diff --git a/fhem/FHEM/WMBus.pm b/fhem/FHEM/WMBus.pm
index acce79356..672031555 100644
--- a/fhem/FHEM/WMBus.pm
+++ b/fhem/FHEM/WMBus.pm
@@ -1,2331 +1,2300 @@
-# $Id$
-
-package WMBus;
-
-use strict;
-use warnings;
-use feature qw(say);
-use Scalar::Util qw(looks_like_number);
-use Digest::CRC; # libdigest-crc-perl
-eval "use Crypt::Mode::CBC"; # cpan -i Crypt::Mode::CBC
-my $hasCBC = ($@)?0:1;
-eval "use Crypt::Mode::CTR"; # cpan -i Crypt::Mode::CTR
-my $hasCTR = ($@)?0:1;
-
-require Exporter;
-my @ISA = qw(Exporter);
-my @EXPORT = qw(new parse parseLinkLayer parseApplicationLayer manId2ascii type2string setFrameType getFrameType VIF_TYPE_MANUFACTURER_SPECIFIC);
-
-sub manId2ascii($$);
-
-
-use constant {
-  # Transport Layer block size
-  TL_BLOCK_SIZE => 10,
-  # Link Layer block size
-  LL_BLOCK_SIZE => 16,
-  # size of CRC in bytes
-  CRC_SIZE => 2,
-
-  # sent by meter
-  SND_NR => 0x44, # Send, no reply
-  SND_IR => 0x46, # Send installation request, must reply with CNF_IR
-  ACC_NR => 0x47,
-  ACC_DMD => 0x48,
-  
-  # sent by controller
-  SND_NKE => 0x40, # Link reset
-  CNF_IR => 0x06, 
-  
-  # CI field
-  CI_RESP_4 => 0x7a,  # Response from device, 4 Bytes
-  CI_RESP_12 => 0x72, # Response from device, 12 Bytes
-  CI_RESP_0 => 0x78,  # Response from device, 0 Byte header, variable length
-  CI_ERROR => 0x70,   # Error from device, only specified for wired M-Bus but used by Easymeter WMBUS module
-  CI_TL_4 => 0x8a,    # Transport layer from device, 4 Bytes
-  CI_TL_12 => 0x8b,   # Transport layer from device, 12 Bytes
-  CI_ELL_2 => 0x8c,   # Extended Link Layer, 2 Bytes
-  CI_ELL_6 => 0x8e,   # Extended Link Layer, 6 Bytes
-  CI_ELL_8 => 0x8d,   # Extended Link Layer, 8 Bytes (see https://www.telit.com/wp-content/uploads/2017/09/Telit_Wireless_M-bus_2013_Part4_User_Guide_r14.pdf, 2.3.4)
-  CI_ELL_16 => 0x8f,  # Extended Link Layer, 16 Bytes (see https://www.telit.com/wp-content/uploads/2017/09/Telit_Wireless_M-bus_2013_Part4_User_Guide_r14.pdf, 2.3.4)
-  CI_AFL => 0x90,     # Authentification and Fragmentation Layer, variable size
-  CI_RESP_SML_4 => 0x7e, # Response from device, 4 Bytes, application layer SML encoded
-  CI_RESP_SML_12 => 0x7f, # Response from device, 12 Bytes, application layer SML encoded  
-  CI_SND_UD_MODE_1 => 0x51, # The master can send data to a slave using a SND_UD with CI-Field 51h for mode 1 or 55h for mode 2
-  CI_SND_UD_MODE_2 => 0x55,
-  
-  # DIF types (Data Information Field), see page 32
-  DIF_NONE => 0x00,
-  DIF_INT8 => 0x01,
-  DIF_INT16 => 0x02,
-  DIF_INT24 => 0x03,
-  DIF_INT32 => 0x04,
-  DIF_FLOAT32 => 0x05,
-  DIF_INT48 => 0x06,
-  DIF_INT64 => 0x07,
-  DIF_READOUT => 0x08,
-  DIF_BCD2 => 0x09,
-  DIF_BCD4 => 0x0a,
-  DIF_BCD6 => 0x0b,
-  DIF_BCD8 => 0x0c,
-  DIF_VARLEN => 0x0d,
-  DIF_BCD12 => 0x0e,
-  DIF_SPECIAL => 0x0f,
-
-  
-  DIF_IDLE_FILLER => 0x2f,
-  
-  DIF_EXTENSION_BIT => 0x80,
-  
-  VIF_EXTENSION        => 0xFB,                     # true VIF is given in the first VIFE and is coded using table 8.4.4 b) (128 new VIF-Codes)
-  VIF_EXTENSION_BIT    => 0x80,
-  
-
-  ERR_NO_ERROR => 0,
-  ERR_CRC_FAILED => 1,
-  ERR_UNKNOWN_VIFE => 2,
-  ERR_UNKNOWN_VIF => 3,
-  ERR_TOO_MANY_DIFE => 4,
-  ERR_UNKNOWN_LVAR => 5,
-  ERR_UNKNOWN_DATAFIELD => 6,
-  ERR_UNKNOWN_CIFIELD => 7,
-  ERR_DECRYPTION_FAILED => 8,
-  ERR_NO_AESKEY => 9,
-  ERR_UNKNOWN_ENCRYPTION => 10,
-  ERR_TOO_MANY_VIFE => 11,
-  ERR_MSG_TOO_SHORT => 12,
-  ERR_SML_PAYLOAD => 13,
-  ERR_FRAGMENT_UNSUPPORTED => 14,
-  ERR_UNKNOWN_COMPACT_FORMAT => 15,
-  ERR_CIPHER_NOT_INSTALLED => 16,
-  ERR_LINK_LAYER_INVALID => 17,
-  
-  VIF_TYPE_MANUFACTURER_SPECIFIC => 'MANUFACTURER SPECIFIC',
- 
-  # TYPE C transmission uses two different frame types
-  # see http://www.st.com/content/ccc/resource/technical/document/application_note/3f/fb/35/5a/25/4e/41/ba/DM00233038.pdf/files/DM00233038.pdf/jcr:content/translations/en.DM00233038.pdf
-  FRAME_TYPE_A => 'A',
-  FRAME_TYPE_B => 'B',
-  
-};
-
-sub valueCalcNumeric($$) {
-  my $value = shift;
-  my $dataBlock = shift;
-
-  # some sanity checks on the provided data
-  if (defined($value) && defined($dataBlock->{valueFactor}) && looks_like_number($value))
-  {
-    return $value * $dataBlock->{valueFactor};
-  } else {
-    return 0;
-  }
-  
-}
-
-sub valueCalcDate($$) {
-  my $value = shift;
-  my $dataBlock = shift;
-  
-  #value is a 16bit int
-  
-  #day: UI5 [1 to 5] <1 to 31>
-  #month: UI4 [9 to 12] <1 to 12>
-  #year: UI7[6 to 8,13 to 16] <0 to 99>
-  
-  #   YYYY MMMM YYY DDDDD
-  # 0b0000 1100 111 11111 = 31.12.2007
-  # 0b0000 0100 111 11110 = 30.04.2007
-
-  my $day = ($value & 0b11111);
-  my $month = (($value & 0b111100000000) >> 8);
-  my $year = ((($value & 0b1111000000000000) >> 9) | (($value & 0b11100000) >> 5)) + 2000;
-  if ($day > 31 || $month > 12 || $year > 2099) {
-    return sprintf("invalid: %x", $value);
-  } else {
-    return sprintf("%04d-%02d-%02d", $year, $month, $day);
-  }
-}
-
-sub valueCalcDateTime($$) {
-  my $value = shift;
-  my $dataBlock = shift;
-
-#min: UI6 [1 to 6] <0 to 59>
-#hour: UI5 [9 to13] <0 to 23>
-#day: UI5 [17 to 21] <1 to 31>
-#month: UI4 [25 to 28] <1 to 12>
-#year: UI7[22 to 24,29 to 32] <0 to 99>
-# IV:
-# B1[8] {time invalid}:
-# IV<0> :=
-#valid,
-#IV>1> := invalid
-#SU: B1[16] {summer time}:
-#SU<0> := standard time,
-#SU<1> := summer time
-#RES1: B1[7] {reserved}: <0>
-#RES2: B1[14] {reserved}: <0>
-#RES3: B1[15] {reserved}: <0>
-  
-  
-  my $datePart = $value >> 16;
-  my $timeInvalid = $value & 0b10000000;
-  
-  my $dateTime = valueCalcDate($datePart, $dataBlock);
-  if ($timeInvalid == 0) {
-    my $min = ($value & 0b111111);
-    my $hour = ($value >> 8) & 0b11111;
-    my $su = ($value & 0b1000000000000000);
-    if ($min > 59 || $hour > 23) {
-      $dateTime = sprintf('invalid: %x', $value);
-    } else {
-      $dateTime .= sprintf(' %02d:%02d %s', $hour, $min, $su ? 'DST' : '');
-    }
-  }
-  
-  return $dateTime;  
-}
-
-sub valueCalcHex($$) {
-  my $value = shift;
-  my $dataBlock = shift;
-
-  return sprintf("%x", $value);
-}
-
-sub valueCalcu($$) {
-  my $value = shift;
-  my $dataBlock = shift;
-
-  my $result = '';
-  
-  $result = ($value & 0b00001000 ? 'upper' : 'lower') . ' limit';
-  return $result;
-}
-
-sub valueCalcufnn($$) {
-  my $value = shift;
-  my $dataBlock = shift;
-
-  my $result = '';
-  
-  $result = ($value & 0b00001000 ? 'upper' : 'lower') . ' limit';
-  $result .= ', ' . ($value & 0b00000100 ? 'first' : 'last');
-  $result .= sprintf(', duration %d', $value & 0b11);
-  return $result;
-}
-
-sub valueCalcMultCorr1000($$) {
-  my $value = shift;
-  my $dataBlock = shift;
-  
-  $dataBlock->{value} *= 1000;
-
-  return "correction by factor 1000";
-}
-
-
-my %TimeSpec = (
-  0b00 => 's', # seconds
-  0b01 => 'm', # minutes
-  0b10 => 'h', # hours
-  0b11 => 'd', # days
-);
-
-sub valueCalcTimeperiod($$) {
-  my $value = shift;
-  my $dataBlock = shift;
-  
-  $dataBlock->{unit} = $TimeSpec{$dataBlock->{exponent}};
-  return $value;
-}
-
-# VIF types (Value Information Field), see page 32
-my %VIFInfo = (
-  VIF_ENERGY_WATT  => {                     #  10(nnn-3) Wh  0.001Wh to 10000Wh
-    typeMask     => 0b01111000,
-    expMask      => 0b00000111,
-    type         => 0b00000000,
-    bias         => -3,
-    unit         => 'Wh',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_ENERGY_JOULE   => {                     #  10(nnn) J     0.001kJ to 10000kJ
-    typeMask     => 0b01111000,
-    expMask      => 0b00000111,
-    type         => 0b00001000,
-    bias         => 0,
-    unit         => 'J',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_VOLUME           => {                     #  10(nnn-6) m3  0.001l to 10000l
-    typeMask     => 0b01111000,
-    expMask      => 0b00000111,
-    type         => 0b00010000,
-    bias         => -6,
-    unit         => 'm³',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_MASS             => {                     #  10(nnn-3) kg  0.001kg to 10000kg
-    typeMask     => 0b01111000,
-    expMask      => 0b00000111,
-    type         => 0b00011000,
-    bias         => -3,
-    unit         => 'kg',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_ON_TIME_SEC      => {                     #  seconds
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100000,
-    bias         => 0,
-    unit         => 'sec',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_ON_TIME_MIN      => {                     #  minutes
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100001,
-    bias         => 0,
-    unit         => 'min',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_ON_TIME_HOURS    => {                     #  hours
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100010,
-    bias         => 0,
-    unit         => 'hours',
-  },
-  VIF_ON_TIME_DAYS    => {                     #  days
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100011,
-    bias         => 0,
-    unit         => 'days',
-  },
-  VIF_OP_TIME_SEC      => {                     #  seconds
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100100,
-    bias         => 0,
-    unit         => 'sec',
-  },
-  VIF_OP_TIME_MIN      => {                     #  minutes
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100101,
-    bias         => 0,
-    unit         => 'min',
-  },
-  VIF_OP_TIME_HOURS    => {                     #  hours
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100110,
-    bias         => 0,
-    unit         => 'hours',
-  },
-  VIF_OP_TIME_DAYS    => {                     #  days
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100111,
-    bias         => 0,
-    unit         => 'days',
-  },
-  VIF_ELECTRIC_POWER   => {                     #  10(nnn-3) W   0.001W to 10000W
-    typeMask     => 0b01111000,
-    expMask      => 0b00000111,
-    type         => 0b00101000,
-    bias         => -3,
-    unit         => 'W',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_THERMAL_POWER    =>  {                    #  10(nnn) J/h   0.001kJ/h to 10000kJ/h
-    typeMask     => 0b01111000,
-    expMask      => 0b00000111,
-    type         => 0b00110000,
-    bias         => 0,
-    unit         => 'J/h',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_VOLUME_FLOW      => {                     #  10(nnn-6) m3/h 0.001l/h to 10000l/h
-    typeMask     => 0b01111000,
-    expMask      => 0b00000111,
-    type         => 0b00111000,
-    bias         => -6,
-    unit         => 'm³/h',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_VOLUME_FLOW_EXT1 => {                     #  10(nnn-7) m3/min 0.0001l/min to 10000l/min
-    typeMask     => 0b01111000,
-    expMask      => 0b00000111,
-    type         => 0b01000000,
-    bias         => -7,
-    unit         => 'm³/min',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_VOLUME_FLOW_EXT2 => {                     #  10(nnn-9) m3/s 0.001ml/s to 10000ml/s
-    typeMask     => 0b01111000,
-    expMask      => 0b00000111,
-    type         => 0b01001000,
-    bias         => -9,
-    unit         => 'm³/s',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_MASS_FLOW         => {                   #  10(nnn-3) kg/h 0.001kg/h to 10000kg/h
-    typeMask     => 0b01111000,
-    expMask      => 0b00000111,
-    type         => 0b01010000,
-    bias         => -3,
-    unit         => 'kg/h',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_FLOW_TEMP         => {                   #  10(nn-3) °C 0.001°C to 1°C
-    typeMask     => 0b01111100,
-    expMask      => 0b00000011,
-    type         => 0b01011000,
-    bias         => -3,
-    unit         => '°C',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_RETURN_TEMP       => {                   #  10(nn-3) °C 0.001°C to 1°C
-    typeMask     => 0b01111100,
-    expMask      => 0b00000011,
-    type         => 0b01011100,
-    bias         => -3,
-    unit         => '°C',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_TEMP_DIFF        => {                    #  10(nn-3) K 1mK to 1000mK
-    typeMask     => 0b01111100,
-    expMask      => 0b00000011,
-    type         => 0b01100000,
-    bias         => -3,
-    unit         => 'K',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_EXTERNAL_TEMP    => {                   #  10(nn-3) °C 0.001°C to 1°C
-    typeMask     => 0b01111100,
-    expMask      => 0b00000011,
-    type         => 0b01100100,
-    bias         => -3,
-    unit         => '°C',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_PRESSURE    => {                        #  10(nn-3) bar  1mbar to 1000mbar
-    typeMask     => 0b01111100,
-    expMask      => 0b00000011,
-    type         => 0b01101000,
-    bias         => -3,
-    unit         => 'bar',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_TIME_POINT_DATE => {                    #  data type G
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01101100,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcDate,
-  },
-  VIF_TIME_POINT_DATE_TIME => {               #  data type F
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01101101,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcDateTime,
-  },
-  VIF_HCA              =>  {                  # Unit for Heat Cost Allocator, dimensonless
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01101110,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_FABRICATION_NO =>  {                    # Fabrication No
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01111000,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_OWNER_NO =>  {                          # Eigentumsnummer (used by Easymeter even though the standard allows this only for writing to a slave)
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01111001,
-    bias         => 0,
-    unit         => '',
-  },  
-  VIF_AVERAGING_DURATION_SEC      => {                     #  seconds
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01110000,
-    bias         => 0,
-    unit         => 'sec',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_AVERAGING_DURATION_MIN      => {                     #  minutes
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01110001,
-    bias         => 0,
-    unit         => 'min',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_AVERAGING_DURATION_HOURS    => {                     #  hours
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01110010,
-    bias         => 0,
-    unit         => 'hours',
-  },
-  VIF_AVERAGING_DURATION_DAYS    => {                     #  days
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01110011,
-    bias         => 0,
-    unit         => 'days',
-  },  
-  VIF_ACTUALITY_DURATION_SEC      => {                     #  seconds
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01110100,
-    bias         => 0,
-    unit         => 'sec',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_ACTUALITY_DURATION_MIN      => {                     #  minutes
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01110101,
-    bias         => 0,
-    unit         => 'min',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_ACTUALITY_DURATION_HOURS    => {                     #  hours
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01110110,
-    bias         => 0,
-    unit         => 'hours',
-  },
-  VIF_ACTUALITY_DURATION_DAYS    => {                     #  days
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01110111,
-    bias         => 0,
-    unit         => 'days',
-  },  
-);  
-
-# Codes used with extension indicator $FD, see 8.4.4 on page 80
-my %VIFInfo_FD = (  
-  VIF_CREDIT  => {                        #  Credit of 10nn-3 of the nominal local legal currency units
-    typeMask     => 0b01111100,
-    expMask      => 0b00000011,
-    type         => 0b00000000,
-    bias         => -3,
-    unit         => '€',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_DEBIT  => {                         #  Debit of 10nn-3 of the nominal local legal currency units
-    typeMask     => 0b01111100,
-    expMask      => 0b00000011,
-    type         => 0b00000100,
-    bias         => -3,
-    unit         => '€',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_ACCESS_NO  => {                     #  Access number (transmission count)
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00001000,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_MEDIUM  => {                        #  Medium (as in fixed header)
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00001001,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_MANUFACTURER  => {                  #  Manufacturer (as in fixed header)
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00001010,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_PARAMETER_SET_ID  => {             #  Parameter set identification
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00001011,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_MODEL_VERSION => {                  #  Model / Version
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00001100,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_HARDWARE_VERSION => {               #  Hardware version #
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00001101,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_FIRMWARE_VERSION => {               #  Firmware version #
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00001110,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_SOFTWARE_VERSION => {               #  Software version #
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00001111,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_ERROR_FLAGS => {                    #  Error flags (binary)
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00010111,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcHex,
-  },
-  VIF_DURATION_SINCE_LAST_READOUT => {    #   Duration since last readout [sec(s)..day(s)]
-    typeMask     => 0b01111100,
-    expMask      => 0b00000011,
-    type         => 0b00101100,
-    bias         => 0,
-    unit         => 's',
-    calcFunc     => \&valueCalcTimeperiod,
-  },
-  VIF_VOLTAGE => {                        #  10nnnn-9 Volts
-    typeMask     => 0b01110000,
-    expMask      => 0b00001111,
-    type         => 0b01000000,
-    bias         => -9,
-    unit         => 'V',
-    calcFunc     => \&valueCalcNumeric,
-  },  
-  VIF_ELECTRICAL_CURRENT => {             #  10nnnn-12 Ampere
-    typeMask     => 0b01110000,
-    expMask      => 0b00001111,
-    type         => 0b01010000,
-    bias         => -12,
-    unit         => 'A',
-    calcFunc     => \&valueCalcNumeric,
-  },  
-  VIF_RECEPTION_LEVEL => {                #   reception level of a received radio device.
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01110001,
-    bias         => 0,
-    unit         => 'dBm',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_STATE_PARAMETER_ACTIVATION => {     #  State of parameter activation
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01100110,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_SPECIAL_SUPPLIER_INFORMATION => {     #  Special supplier information
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01100111,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  
-  VIF_FD_RESERVED => {                   # Reserved
-    typeMask     => 0b01110000,
-    expMask      => 0b00000000,
-    type         => 0b01110000,
-    bias         => 0,
-    unit         => 'Reserved',
-  },
-  
-);
-
-# Codes used with extension indicator $FB
-my %VIFInfo_FB = (                              
-  VIF_ENERGY  => {                     #  Energy 10(n-1) MWh  0.1MWh to 1MWh
-    typeMask     => 0b01111110,
-    expMask      => 0b00000001,
-    type         => 0b00000000,
-    bias         => -1,
-    unit         => 'MWh',
-    calcFunc     => \&valueCalcNumeric,
-  },
-);
-
-
-# Codes used for an enhancement of VIFs other than $FD and $FB
-my %VIFInfo_other = (       
-  VIF_ERROR_NONE => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00000000,
-    bias         => 0,
-    unit         => 'No error',
-  },
-  VIF_TOO_MANY_DIFES => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00000001,
-    bias         => 0,
-    unit         => 'Too many DIFEs',
-  },
-
-  VIF_ILLEGAL_VIF_GROUP => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00001100,
-    bias         => 0,
-    unit         => 'Illegal VIF-Group',
-  },
-
-  VIF_DATA_UNDERFLOW => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00010111,
-    bias         => 0,
-    unit         => 'Data underflow',
-  },
-
-
-  VIF_PER_SECOND => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100000,
-    bias         => 0,
-    unit         => 'per second',
-  },
-  VIF_PER_MINUTE => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100001,
-    bias         => 0,
-    unit         => 'per minute',
-  },
-  VIF_PER_HOUR => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100010,
-    bias         => 0,
-    unit         => 'per hour',
-  },
-  VIF_PER_DAY => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100011,
-    bias         => 0,
-    unit         => 'per day',
-  },
-  VIF_PER_WEEK => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100100,
-    bias         => 0,
-    unit         => 'per week',
-  },
-  VIF_PER_MONTH => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100101,
-    bias         => 0,
-    unit         => 'per month',
-  },
-  VIF_PER_YEAR => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100110,
-    bias         => 0,
-    unit         => 'per year',
-  },
-  VIF_PER_REVOLUTION => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00100111,
-    bias         => 0,
-    unit         => 'per revolution/measurement',
-  },
-  VIF_PER_INCREMENT_INPUT => {
-    typeMask     => 0b01111110,
-    expMask      => 0b00000000,
-    type         => 0b00101000,
-    bias         => 0,
-    unit         => 'increment per input pulse on input channnel #',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_PER_INCREMENT_OUTPUT => {
-    typeMask     => 0b01111110,
-    expMask      => 0b00000000,
-    type         => 0b00101010,
-    bias         => 0,
-    unit         => 'increment per output pulse on output channnel #',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_PER_LITER => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00101100,
-    bias         => 0,
-    unit         => 'per liter',
-  },
-  VIF_PER_M3 => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00101101,
-    bias         => 0,
-    unit         => 'per m³',
-  },
-  VIF_PER_KG => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00101110,
-    bias         => 0,
-    unit         => 'per kg',
-  },  
-  VIF_PER_K => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00101111,
-    bias         => 0,
-    unit         => 'per K',
-  },  
-  VIF_PER_KWH => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00110000,
-    bias         => 0,
-    unit         => 'per kWh',
-  },  
-  VIF_PER_GJ => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00110001,
-    bias         => 0,
-    unit         => 'per GJ',
-  },  
-  VIF_PER_KW => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00110010,
-    bias         => 0,
-    unit         => 'per kW',
-  },  
-  VIF_PER_KL => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00110011,
-    bias         => 0,
-    unit         => 'per (K*l)',
-  },  
-  VIF_PER_V => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00110100,
-    bias         => 0,
-    unit         => 'per V',
-  },  
-  VIF_PER_A => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00110101,
-    bias         => 0,
-    unit         => 'per A',
-  },  
-  VIF_PER_MULT_S => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00110110,
-    bias         => 0,
-    unit         => 'multiplied by sek',
-  },  
-  VIF_PER_MULT_SV => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00110111,
-    bias         => 0,
-    unit         => 'multiplied by sek / V',
-  },  
-  VIF_PER_MULT_SA => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00111000,
-    bias         => 0,
-    unit         => 'multiplied by sek / A',
-  },  
-
-  VIF_START_DATE_TIME => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00111001,
-    bias         => 0,
-    unit         => 'start date(/time) of',
-  },
-  
-  VIF_ACCUMULATION_IF_POSITIVE => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b00111011,
-    bias         => 0,
-    unit         => 'Accumulation only if positive contribution',
-  },
-  
-  VIF_DURATION_NO_EXCEEDS => {
-    typeMask     => 0b01110111,
-    expMask      => 0b00000000,
-    type         => 0b01000001,
-    bias         => 0,
-    unit         => '# of exceeds',
-    calcFunc     => \&valueCalcu,
-  },
-
-  VIF_DURATION_LIMIT_EXCEEDED => {
-    typeMask     => 0b01110000,
-    expMask      => 0b00000000,
-    type         => 0b01010000,
-    bias         => 0,
-    unit         => 'duration of limit exceeded',
-    calcFunc     => \&valueCalcufnn,
-  },
-
-  VIF_MULTIPLICATIVE_CORRECTION_FACTOR => {
-    typeMask     => 0b01111000,
-    expMask      => 0b00000111,
-    type         => 0b01110000,
-    bias         => -6,
-    unit         => '',
-  },  
-  VIF_MULTIPLICATIVE_CORRECTION_FACTOR_1000 => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01111101,
-    bias         => 0,
-    unit         => '',
-    calcFunc     => \&valueCalcMultCorr1000,
-  },  
-  VIF_FUTURE_VALUE => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01111110,
-    bias         => 0,
-    unit         => '',
-  },  
-  VIF_MANUFACTURER_SPECIFIC => {
-    typeMask     => 0b01111111,
-    expMask      => 0b00000000,
-    type         => 0b01111111,
-    bias         => 0,
-    unit         => 'manufacturer specific',
-  },  
-  
-);
-
-# For Easymeter (manufacturer specific)
-my %VIFInfo_ESY = (       
-  VIF_ELECTRIC_POWER_PHASE => {
-    typeMask     => 0b01000000,
-    expMask      => 0b00000000,
-    type         => 0b00000000,
-    bias         => -2,
-    unit         => 'W',
-    calcFunc     => \&valueCalcNumeric,
-  },
-  VIF_ELECTRIC_POWER_PHASE_NO => {
-    typeMask     => 0b01111110,
-    expMask      => 0b00000000,
-    type         => 0b00101000,
-    bias         => 0,
-    unit         => 'phase #',
-    calcFunc     => \&valueCalcNumeric,
-  },
-);
-
-# For Kamstrup (manufacturer specific)
-my %VIFInfo_KAM = (       
-  VIF_KAMSTRUP_INFO => {
-    typeMask     => 0b00000000,
-    expMask      => 0b00000000,
-    type         => 0b00000000,
-    bias         => 0,
-    unit         => '',
-  },
-);
-
-
-# see 4.2.3, page 24
-my %validDeviceTypes = (
- 0x00 => 'Other',
- 0x01 => 'Oil',
- 0x02 => 'Electricity',
- 0x03 => 'Gas',
- 0x04 => 'Heat',
- 0x05 => 'Steam',
- 0x06 => 'Warm Water (30 °C ... 90 °C)',
- 0x07 => 'Water',
- 0x08 => 'Heat Cost Allocator',
- 0x09 => 'Compressed Air',
- 0x0a => 'Cooling load meter (Volume measured at return temperature: outlet)',
- 0x0b => 'Cooling load meter (Volume measured at flow temperature: inlet)',
- 0x0c => 'Heat (Volume measured at flow temperature: inlet)',
- 0x0d => 'Heat / Cooling load meter',
- 0x0e => 'Bus / System component',
- 0x0f => 'Unknown Medium',
- 0x10 => 'Reserved for utility meter',
- 0x11 => 'Reserved for utility meter',
- 0x12 => 'Reserved for utility meter',
- 0x13 => 'Reserved for utility meter',
- 0x14 => 'Calorific value',
- 0x15 => 'Hot water (> 90 °C)',
- 0x16 => 'Cold water',
- 0x17 => 'Dual register (hot/cold) Water meter',
- 0x18 => 'Pressure',
- 0x19 => 'A/D Converter',
- 0x1a => 'Smokedetector',
- 0x1b => 'Room sensor (e.g. temperature or humidity)',
- 0x1c => 'Gasdetector',
- 0x1d => 'Reserved for sensors',
- 0x1e => 'Reserved for sensors',
- 0x1f => 'Reserved for sensors',
- 0x20 => 'Breaker (electricity)',
- 0x21 => 'Valve (gas)',
- 0x22 => 'Reserved for switching devices',
- 0x23 => 'Reserved for switching devices',
- 0x24 => 'Reserved for switching devices',
- 0x25 => 'Customer unit (Display device)',
- 0x26 => 'Reserved for customer units',
- 0x27 => 'Reserved for customer units',
- 0x28 => 'Waste water',
- 0x29 => 'Garbage',
- 0x2a => 'Carbon dioxide',
- 0x2b => 'Environmental meter',
- 0x2c => 'Environmental meter',
- 0x2d => 'Environmental meter',
- 0x2e => 'Environmental meter',
- 0x2f => 'Environmental meter',
- 0x31 => 'OMS MUC',
- 0x32 => 'OMS unidirectional repeater',
- 0x33 => 'OMS bidirectional repeater',
- 0x37 => 'Radio converter (Meter side)',
-);
-
-
-# bitfield, errors can be combined, see 4.2.3.2 on page 22
-my %validStates = (
-  0x00 => 'no errors',
-  0x01 => 'application busy',
-  0x02 => 'any application error',
-  0x03 => 'abnormal condition/alarm',
-  0x04 => 'battery low',
-  0x08 => 'permanent error',
-  0x10 => 'temporary error',
-  0x20 => 'specific to manufacturer',
-  0x40 => 'specific to manufacturer',
-  0x80 => 'specific to manufacturer',
-  
-);
-
-my %encryptionModes = (
-  0x00 => 'standard unsigned',
-  0x01 => 'signed data telegram',
-  0x02 => 'static telegram',
-  0x03 => 'reserved',
-);
-
-my %functionFieldTypes = (
-  0b00 => 'Instantaneous value',
-  0b01 => 'Maximum value',
-  0b10 => 'Minimum value',
-  0b11 => 'Value during error state',
-);
-
-
-sub type2string($$) {
-  my $class = shift;
-  my $type = shift;
-  
-  return $validDeviceTypes{$type} || 'unknown';
-}
-
-sub state2string($$) {
-  my $class = shift;
-  my $state = shift;
-  
-  my @result = ();
-  
-  if ($state) {
-    foreach my $stateMask ( keys %validStates ) {
-      push @result, $validStates{$stateMask} if $state & $stateMask;
-    }
-  } else {
-    @result = ($validStates{0});
-  }
-  return @result;
-}
-
-
-sub calcCRC($$) {
-  my $self = shift;
-  my $data = shift;
-  my $ctx = Digest::CRC->new(width=>16, init=>0x0000, xorout=>0xffff, refout=>0, poly=>0x3D65, refin=>0, cont=>0);
-
-  $ctx->add($data);
-
-  return $ctx->digest;  
-}
-
-
-sub removeCRC($$)
-{
-  my $self = shift;
-  my $msg = shift;
-  my $i;
-  my $res;
-  my $crc;
-  my $blocksize = LL_BLOCK_SIZE;
-  my $blocksize_with_crc = LL_BLOCK_SIZE + $self->{crc_size};
-  my $crcoffset;
-  
-  my $msgLen = $self->{datalen}; # size without CRCs
-  my $noOfBlocks = $self->{datablocks}; # total number of data blocks, each with a CRC appended
-  my $rest = $msgLen % LL_BLOCK_SIZE; # size of the last data block, can be smaller than 16 bytes
-  
-  
-  #print "crc_size $self->{crc_size}\n";
-  
-  return $msg if $self->{crc_size} == 0;
-
-  # each block is 16 bytes + 2 bytes CRC
-  
-  #print "Länge $msgLen Anz. Blöcke $noOfBlocks rest $rest\n";
-  
-  for ($i=0; $i < $noOfBlocks; $i++) {
-    $crcoffset = $blocksize_with_crc * $i + LL_BLOCK_SIZE;
-    #print "$i: crc offset $crcoffset\n";
-    if ($rest > 0 && $crcoffset + $self->{crc_size} > ($noOfBlocks - 1) * $blocksize_with_crc + $rest) {
-      # last block is smaller
-      $crcoffset = ($noOfBlocks - 1) * $blocksize_with_crc + $rest;
-      #print "last crc offset $crcoffset\n";
-      $blocksize = $msgLen - ($i * $blocksize); 
-    }
-    
-    $crc = unpack('n',substr($msg, $crcoffset, $self->{crc_size}));
-    #printf("%d: CRC %x, calc %x blocksize $blocksize\n", $i, $crc, $self->calcCRC(substr($msg, $blocksize_with_crc*$i, $blocksize))); 
-    if ($crc != $self->calcCRC(substr($msg, $blocksize_with_crc*$i, $blocksize))) {
-      $self->{errormsg} = "crc check failed for block $i";
-      $self->{errorcode} = ERR_CRC_FAILED;
-      return 0;
-    }
-    $res .= substr($msg, $blocksize_with_crc*$i, $blocksize);
-  }
-
-  return $res;
-}
-
-
-sub manId2hex($$)
-{
-  my $class = shift;
-  my $idascii = shift;
-  
-  return (ord(substr($idascii,1,1))-64) << 10 | (ord(substr($idascii,2,1))-64) << 5 | (ord(substr($idascii,3,1))-64);
-}
-
-sub manId2ascii($$)
-{
-  my $class = shift;
-  my $idhex = shift;
-    
-  return chr(($idhex >> 10) + 64) . chr((($idhex >> 5) & 0b00011111) + 64) . chr(($idhex & 0b00011111) + 64);
-}
-
-
-sub new {
-  my $class = shift;
-  my $self = {};
-  bless $self, $class;
-  
-  $self->_initialize();
-  return $self;
-}
-
-sub _initialize {
-  my $self = shift;
-  
-  $self->{crc_size} = CRC_SIZE;
-  $self->{frame_type} = FRAME_TYPE_A; # default
-}
-
-sub setCRCsize {
-  my $self = shift;
-
-  $self->{crc_size} = shift;
-}
-
-sub getCRCsize {
-  my $self = shift;
-
-  return $self->{crc_size};
-}
-
-sub decodeConfigword($) {
-  my $self = shift;
-  
-  #printf("cw: %01x %01x\n", $self->{cw_1}, $self->{cw_2});
-  $self->{cw_parts}{mode}             = ($self->{cw_2} & 0b00011111);
-  #printf("mode: %02x\n", $self->{cw_parts}{mode});
-  if ($self->{cw_parts}{mode} == 5 || $self->{cw_parts}{mode} == 0) {
-    $self->{cw_parts}{bidirectional}    = ($self->{cw_2} & 0b10000000) >> 7;
-    $self->{cw_parts}{accessability}    = ($self->{cw_2} & 0b01000000) >> 6;
-    $self->{cw_parts}{synchronous}      = ($self->{cw_2} & 0b00100000) >> 5;
-    $self->{cw_parts}{encrypted_blocks} = ($self->{cw_1} & 0b11110000) >> 4;
-    $self->{cw_parts}{content}          = ($self->{cw_1} & 0b00001100) >> 2;
-    $self->{cw_parts}{repeated_access}  = ($self->{cw_1} & 0b00000010) >> 1;
-    $self->{cw_parts}{hops}             = ($self->{cw_1} & 0b00000001);
-  } #elsif ($self->{cw_parts}{mode} == 7) {
-    # ToDo: wo kommt das dritte Byte her?
-  #  $self->{cw_parts}{mode}             = $self->{cw} & 0b0000111100000000 >> 8;
-  #}
-}
-
-sub decodeBCD($$$) {
-  my $self = shift;
-  my $digits = shift;
-  my $bcd = shift;
-  my $byte;
-  my $val=0;
-  my $mult=1;
-  
-  #print "bcd:" . unpack("H*", $bcd) . "\n";
-  
-  for (my $i = 0; $i < $digits/2; $i++) {
-    $byte = unpack('C',substr($bcd, $i, 1));
-    $val += ($byte & 0x0f) * $mult;
-    $mult *= 10;
-    $val += (($byte & 0xf0) >> 4) * $mult;
-    $mult *= 10;
-  }
-  return $val;
-}
-
-sub findVIF($$$) {
-  my $vif = shift;
-  my $vifInfoRef = shift;
-  my $dataBlockRef = shift;
-  my $bias;
-  
-  if (defined $vifInfoRef) {
-    VIFID: foreach my $vifType ( keys %$vifInfoRef ) { 
-    
-      #printf "vifType $vifType VIF $vif typeMask $vifInfoRef->{$vifType}{typeMask} type $vifInfoRef->{$vifType}{type}\n"; 
-    
-      if (($vif & $vifInfoRef->{$vifType}{typeMask}) == $vifInfoRef->{$vifType}{type}) {
-        #printf " match vifType $vifType\n"; 
-        
-        $bias = $vifInfoRef->{$vifType}{bias};
-        $dataBlockRef->{exponent} = $vif & $vifInfoRef->{$vifType}{expMask};
-        
-        $dataBlockRef->{type} = $vifType;
-        $dataBlockRef->{unit} = $vifInfoRef->{$vifType}{unit};
-        if (defined $dataBlockRef->{exponent} && defined $bias) {
-          $dataBlockRef->{valueFactor} = 10 ** ($dataBlockRef->{exponent} + $bias);
-        } else {
-          $dataBlockRef->{valueFactor} = 1;
-        }
-        $dataBlockRef->{calcFunc} = $vifInfoRef->{$vifType}{calcFunc};
-        
-        #printf("type %s bias %d exp %d valueFactor %d unit %s\n", $dataBlockRef->{type}, $bias, $dataBlockRef->{exponent}, $dataBlockRef->{valueFactor},$dataBlockRef->{unit});
-        return 1;
-      }
-    }
-    #printf "no match!\n";
-    return 0;
-  }
-  return 1;
-}
-
-sub decodePlaintext($$$) {
-  my $self = shift;
-  my $vib = shift;
-  my $dataBlockRef = shift;
-  my $offset = shift;
-  my $vifLength = unpack('C', substr($vib,$offset++,1));
-  
-  $dataBlockRef->{type} = "see unit";
-  $dataBlockRef->{unit} = substr($vib, $offset, $vifLength);
-  $dataBlockRef->{unit} = reverse($dataBlockRef->{unit}) unless $self->{mode_bit}; 
-  $offset += $vifLength;
-  return $offset;
-}
-
-sub decodeValueInformationBlock($$$) {
-  my $self = shift;
-  my $vib = shift;
-  my $dataBlockRef = shift;
-  
-  my $offset = 0;
-  my $vif;
-  my $vifInfoRef;
-  my $vifExtension = 0;
-  my $vifExtNo = 0;
-  my $isExtension;
-  my $dataBlockExt;
-  my @VIFExtensions = ();
-  my $analyzeVIF = 1;
-
-  $dataBlockRef->{type}  = '';
-  # The unit and multiplier is taken from the table for primary VIF
-  $vifInfoRef = \%VIFInfo;
-  
-
-  EXTENSION: while (1) {
-    $vif = unpack('C', substr($vib,$offset++,1));
-    $isExtension = $vif & VIF_EXTENSION_BIT;
-    #printf("vif: %x isExtension %d\n", $vif, $isExtension);
-    
-    # Is this an extension?
-    last EXTENSION if (!$isExtension);
-    
-    # yes, process extension
-
-    $vifExtNo++;
-    if ($vifExtNo > 10) {
-      $dataBlockRef->{errormsg} = 'too many VIFE';
-      $dataBlockRef->{errorcode} = ERR_TOO_MANY_VIFE;
-      last EXTENSION;
-    }
-    
-    # switch to extension codes
-    $vifExtension = $vif;
-    $vif &= ~VIF_EXTENSION_BIT;
-    #printf("vif ohne extension: %x\n", $vif);
-    if ($vif == 0x7D) {
-      $vifInfoRef = \%VIFInfo_FD;
-    } elsif ($vif == 0x7B) {
-      $vifInfoRef = \%VIFInfo_FB;
-    } elsif ($vif == 0x7C) {
-      # Plaintext VIF
-      $offset = $self->decodePlaintext($vib, $dataBlockRef, $offset);
-      $analyzeVIF = 0;
-      last EXTENSION;
-    } elsif ($vif == 0x7F) {
-      
-      if ($self->{manufacturer} eq 'ESY') {
-        # Easymeter
-        $vif = unpack('C', substr($vib,$offset++,1));
-        $vifInfoRef = \%VIFInfo_ESY;
-      } elsif ($self->{manufacturer} eq 'KAM') {
-        $vif = unpack('C', substr($vib,$offset++,1));
-        $vifInfoRef = \%VIFInfo_KAM;       
-      } else {
-        # manufacturer specific data, can't be interpreted
-        
-        $dataBlockRef->{type} = VIF_TYPE_MANUFACTURER_SPECIFIC;
-        $dataBlockRef->{unit} = "";
-        $analyzeVIF = 0;
-      }
-      last EXTENSION;
-    } else {
-      # enhancement of VIFs other than $FD and $FB (see page 84ff.)
-      #print "other extension\n";
-      $dataBlockExt = {};
-      if ($self->{manufacturer} eq 'ESY') {
-        $vifInfoRef = \%VIFInfo_ESY;
-        $dataBlockExt->{value} = unpack('C',substr($vib,2,1)) * 100;
-      } else {
-        $dataBlockExt->{value} = $vif;
-        $vifInfoRef = \%VIFInfo_other;
-      }
-      
-      if (findVIF($vif, $vifInfoRef, $dataBlockExt)) {
-        push @VIFExtensions, $dataBlockExt;
-      } else {
-        $dataBlockRef->{type} = 'unknown';
-        $dataBlockRef->{errormsg} = "unknown VIFE " . sprintf("%x", $vifExtension) . " at offset " . ($offset-1);
-        $dataBlockRef->{errorcode} = ERR_UNKNOWN_VIFE;    
-      }    
-    }
-    last EXTENSION if (!$isExtension);
-  }
-
-  if ($analyzeVIF) {  
-    if ($vif == 0x7C) {
-      # Plaintext VIF
-      $offset = $self->decodePlaintext($vib, $dataBlockRef, $offset);
-    } elsif (findVIF($vif, $vifInfoRef, $dataBlockRef) == 0) {
-      $dataBlockRef->{errormsg} = "unknown VIF " . sprintf("%x", $vifExtension) . " at offset " . ($offset-1);
-      $dataBlockRef->{errorcode} = ERR_UNKNOWN_VIFE;    
-    }
-  }
-  $dataBlockRef->{VIFExtensions} = \@VIFExtensions;
-
-  if ($dataBlockRef->{type} eq '') {
-    $dataBlockRef->{type} = 'unknown';
-    $dataBlockRef->{errormsg} = sprintf("in VIFExtension %x unknown VIF %x",$vifExtension, $vif);
-    $dataBlockRef->{errorcode} = ERR_UNKNOWN_VIF;
-  }
-  
-  return $offset;
-  
-  
-}
-
-
-sub decodeDataInformationBlock($$$) {
-  my $self = shift;
-  my $dib = shift;
-  my $dataBlockRef = shift;
-  
-  my $dif;
-  my $tariff = 0;
-  my $difExtNo = 0;
-  my $offset;
-  my $devUnit = 0;
-  
-  $dif = unpack('C', $dib);
-  $offset = 1;
-  my $isExtension = $dif & DIF_EXTENSION_BIT;
-  my $storageNo = ($dif & 0b01000000) >> 6;
-  my $functionField = ($dif & 0b00110000) >> 4;
-  my $df = $dif & 0b00001111;
-
-  #printf("dif %x storage %d\n", $dif, $storageNo);
-  
-  EXTENSION: while ($isExtension) {
-    $dif = unpack('C', substr($dib,$offset,1));
-    last EXTENSION if (!defined $dif);
-    $offset++;
-    $isExtension = $dif & DIF_EXTENSION_BIT;
-    $difExtNo++;
-    if ($difExtNo > 10) {
-      $dataBlockRef->{errormsg} = 'too many DIFE';
-      $dataBlockRef->{errorcode} = ERR_TOO_MANY_DIFE;
-      last EXTENSION;
-    }
-    
-    $storageNo |= ($dif & 0b00001111) << ($difExtNo*4)+1;
-    $tariff    |= (($dif & 0b00110000) >> 4) << (($difExtNo-1)*2);
-    $devUnit   |= (($dif & 0b01000000) >> 6) << ($difExtNo-1);
-    #printf("dife %x extno %d storage %d\n", $dif, $difExtNo, $storageNo);
-  }
-  
-  $dataBlockRef->{functionField} = $functionField;
-  $dataBlockRef->{functionFieldText} = $functionFieldTypes{$functionField};
-  $dataBlockRef->{dataField} = $df;
-  $dataBlockRef->{storageNo} = $storageNo;
-  $dataBlockRef->{tariff} = $tariff;
-  $dataBlockRef->{devUnit} = $devUnit;
-  
-  #printf("in DIF: datafield %x\n", $dataBlockRef->{dataField});
-  #print "offset in dif $offset\n";
-  return $offset;
-}
-
-sub decodeDataRecordHeader($$$) {
-  my $self = shift;
-  my $drh = shift;
-  my $dataBlockRef = shift;
-  
-  my $offset = $self->decodeDataInformationBlock($drh,$dataBlockRef);
-
-  
-  $offset += $self->decodeValueInformationBlock(substr($drh,$offset),$dataBlockRef);
-  #printf("in DRH: type %s\n", $dataBlockRef->{type});
-  
-  return $offset;
-}
-
-
-
-sub decodePayload($$) {
-  my $self = shift;
-  my $payload = shift;
-  my $offset = 0;
-  my $dif;
-  my $vif;
-  my $scale;
-  my $value;
-  my $dataBlockNo = 0;
-  
-  
-  my @dataBlocks = ();
-  my $dataBlock;
-
-  
-  PAYLOAD: while ($offset < length($payload)) {
-    $dataBlockNo++;
-    
-    # create a new anonymous hash reference
-    $dataBlock = {};
-    $dataBlock->{number} = $dataBlockNo;
-    $dataBlock->{unit} = '';
-    
-    while (unpack('C',substr($payload,$offset,1)) == 0x2f) {
-      # skip filler bytes
-      #printf("skipping filler at offset %d of %d\n", $offset, length($payload));
-      $offset++;
-      if ($offset >= length($payload)) {
-        last PAYLOAD;
-      }
-    }
-    
-    $offset += $self->decodeDataRecordHeader(substr($payload,$offset), $dataBlock);
-    #printf("No. %d, type %x at offset %d\n", $dataBlockNo, $dataBlock->{dataField}, $offset-1);
-    
-    if ($dataBlock->{dataField} == DIF_NONE or $dataBlock->{dataField} == DIF_READOUT) {
-      $dataBlockNo--;
-      $offset++;
-    } elsif ($dataBlock->{dataField} == DIF_BCD2) {
-      $value = $self->decodeBCD(2, substr($payload,$offset,1));
-      $offset += 1;
-    } elsif ($dataBlock->{dataField} == DIF_BCD4) {
-      $value = $self->decodeBCD(4, substr($payload,$offset,2));
-      $offset += 2;
-    } elsif ($dataBlock->{dataField} == DIF_BCD6) {
-      $value = $self->decodeBCD(6, substr($payload,$offset,3));
-      $offset += 3;
-    } elsif ($dataBlock->{dataField} == DIF_BCD8) {
-      $value = $self->decodeBCD(8, substr($payload,$offset,4));
-      $offset += 4;
-    } elsif ($dataBlock->{dataField} == DIF_BCD12) {
-      $value = $self->decodeBCD(12, substr($payload,$offset,6));
-      $offset += 6;
-    } elsif ($dataBlock->{dataField} == DIF_INT8) {
-      $value = unpack('C', substr($payload, $offset, 1));
-      $offset += 1;
-    } elsif ($dataBlock->{dataField} == DIF_INT16) {
-      $value = unpack('v', substr($payload, $offset, 2));
-      $offset += 2;
-    } elsif ($dataBlock->{dataField} == DIF_INT24) {
-      my @bytes = unpack('CCC', substr($payload, $offset, 3));
-      $offset += 3;
-      $value = $bytes[0] + $bytes[1] << 8 + $bytes[2] << 16;
-    } elsif ($dataBlock->{dataField} == DIF_INT32) {
-      $value = unpack('V', substr($payload, $offset, 4));
-      $offset += 4;
-    } elsif ($dataBlock->{dataField} == DIF_INT48) {
-      my @words = unpack('vvv', substr($payload, $offset, 6));
-      $value = $words[0] + ($words[1] << 16) + ($words[2] << 32);
-      $offset += 6;
-    } elsif ($dataBlock->{dataField} == DIF_INT64) {
-      $value = unpack('Q<', substr($payload, $offset, 8));
-      $offset += 8;
-    } elsif ($dataBlock->{dataField} == DIF_FLOAT32) {
-      #not allowed according to wmbus standard, Qundis seems to use it nevertheless
-      $value = unpack('f', substr($payload, $offset, 4));
-      $offset += 4;
-    } elsif ($dataBlock->{dataField} == DIF_VARLEN) {
-      my $lvar = unpack('C',substr($payload, $offset++, 1));
-      #print "in datablock $dataBlockNo: LVAR field " . sprintf("%x", $lvar) . "\n";
-      #printf "payload len %d offset %d\n", length($payload), $offset;
-      if ($lvar <= 0xbf) {
-        if ($dataBlock->{type} eq "MANUFACTURER SPECIFIC") {
-          # special handling, LSE seems to lie about this
-          $value = unpack('H*',substr($payload, $offset, $lvar));
-          #print "VALUE: " . $value . "\n";
-        } else {
-          #  ASCII string with LVAR characters
-          $value = unpack('a*',substr($payload, $offset, $lvar));
-          
-          # check if value only contains printable chars 
-          if(($value =~ tr/\x20-\x7d//c) == 0) {
-          
-            if ($self->{manufacturer} eq 'ESY') {
-              # Easymeter stores the string backwards!
-              $value = reverse($value);
-            }
-          } else {
-            $self->{errormsg} = "Non printable ASCII in LVAR";
-            $self->{errorcode} = ERR_UNKNOWN_DATAFIELD;
-            return 0;
-          }
-        }
-        $offset += $lvar;
-      } elsif ($lvar >= 0xc0 && $lvar <= 0xcf) {
-        #  positive BCD number with (LVAR - C0h) • 2 digits
-        $value = $self->decodeBCD(($lvar-0xc0)*2, substr($payload,$offset,($lvar-0xc0)));
-        $offset += ($lvar-0xc0);
-      } elsif ($lvar >= 0xd0 && $lvar <= 0xdf) {
-        #  negative BCD number with (LVAR - D0h) • 2 digits
-        $value = -$self->decodeBCD(($lvar-0xd0)*2, substr($payload,$offset,($lvar-0xd0)));
-        $offset += ($lvar-0xd0);
-      } else {
-        $self->{errormsg} = "in datablock $dataBlockNo: unhandled LVAR field " . sprintf("%x", $lvar);
-        $self->{errorcode} = ERR_UNKNOWN_LVAR;
-        return 0;
-      }
-    } elsif ($dataBlock->{dataField} == DIF_SPECIAL) {
-      # special functions
-      #print "DIF_SPECIAL at $offset\n";
-      $value = unpack("H*", substr($payload,$offset));
-      last PAYLOAD;
-    } else {
-      $self->{errormsg} = "in datablock $dataBlockNo: unhandled datafield " . sprintf("%x",$dataBlock->{dataField});
-      $self->{errorcode} = ERR_UNKNOWN_DATAFIELD;
-      return 0;
-    }
-    
-    if (defined $dataBlock->{calcFunc}) {
-      $dataBlock->{value} = $dataBlock->{calcFunc}->($value, $dataBlock); 
-      #print "Value raw " . $value . " value calc " . $dataBlock->{value} ."\n";
-    } elsif (defined $value) {
-      $dataBlock->{value} = $value;
-    } else {
-      $dataBlock->{value} = "";
-    }
-    
-    my $VIFExtensions = $dataBlock->{VIFExtensions};
-    for my $VIFExtension (@$VIFExtensions) {
-      $dataBlock->{extension} = $VIFExtension->{unit};
-      if (defined $VIFExtension->{calcFunc}) {
-        #printf("Extension value %d, valueFactor %d\n", $VIFExtension->{value}, $VIFExtension->{valueFactor});
-        $dataBlock->{extension} .= ", " . $VIFExtension->{calcFunc}->($VIFExtension->{value}, $dataBlock); 
-      } elsif (defined $VIFExtension->{value}) {
-        $dataBlock->{extension} .= ", " . sprintf("%x",$VIFExtension->{value});
-      } else {
-        #$dataBlock->{extension} = "";
-      }
-    }
-    undef $value;
-    
-    push @dataBlocks, $dataBlock;
-  }
-  
-  $self->{datablocks} = \@dataBlocks;
-  return 1;
-}
-
-sub decrypt($) {
-  my $self = shift;
-  my $encrypted = shift;
-  my $padding = 2;
-  
-  # see 4.2.5.3, page 26      
-  my $initVector = substr($self->{msg},2,8);
-  for (1..8) {
-    $initVector .= pack('C',$self->{access_no});
-  }
-  
-  if (length($encrypted)%16 == 0) {
-    # no padding if data length is multiple of blocksize
-    $padding = 0;
-  } else {
-    $padding = 2;
-  }
-  #printf("length encrypted %d padding %d\n", length($encrypted), $padding);
-  my $cipher = Crypt::Mode::CBC->new('AES', $padding);
-  return $cipher->decrypt($encrypted, $self->{aeskey}, $initVector);
-}
-
-sub decrypt_mode7($) {
-  my $self = shift;
-  my $encrypted = shift;
-  
-  # see 9.2.4, page 59      
-  my $initVector = '';
-  for (1..16) {
-    $initVector .= pack('C',0x00);
-  }
-  my $cipher = Crypt::Mode::CBC->new('AES', 2);
-  return $cipher->decrypt($encrypted, $self->{aeskey}, $initVector);
-}
-
-# Generate MAC of data
-#
-# Parameter 1: private key as byte string, 16bytes
-# Parameter 2: data fro which mac should be calculated in hexadecimal format, len variable
-# Parameter 3: length of MAC to be generated in bytes
-#
-# Returns: MAC in hexadecimal format
-#
-# This function currently supports data with lentgh of less then 16bytes,
-# MAC for longer data is untested but specified
-#
-# copied from 10_EnOcean.pm
-sub generateMAC($$$$) {
-  my $self = shift;
-	my $private_key = $_[0];
-	my $data = $_[1];
-	my $cmac_len = $_[2];
-
-	#print "Calculating MAC for data $data\n";
-
-	# Pack data to 16byte byte string, padd with 10..0 binary
-	my $data_expanded = pack('H32', $data.'80');
-
-	#print "Exp. data  ".unpack('H32', $data_expanded)."\n";
-
-	# Constants according to specification
-	my $const_zero = pack('H32','00');
-	my $const_rb = pack('H32', '00000000000000000000000000000087');
-
-	# Encrypt zero data with private key to get L
-	my $cipher = Crypt::Rijndael->new($private_key);
-  my $l = $cipher->encrypt($const_zero);
-	#print "L          ".unpack('H32', $l)."\n";
-	#print "L          ".unpack('B128', $l)."\n";
-
-	# Expand L to 128bit string
-	my $l_bit = unpack('B128', $l);
-
-	# K1 and K2 stored as 128bit string
-	my $k1_bit;
-	my $k2_bit;
-
-	# K1 and K2 as binary
-	my $k1;
-	my $k2;
-
-	# Store L << 1 in K1
-	$l_bit =~ /^.(.{127})/;
-	$k1_bit = $1.'0';
-	$k1 = pack('B128', $k1_bit);
-
-	# If MSB of L == 1, K1 = K1 XOR const_Rb
-	if($l_bit =~ m/^1/) {
-		#print "MSB of L is set\n";
-		$k1 = $k1 ^ $const_rb;
-		$k1_bit = unpack('B128', $k1);
-	} else {
-		#print "MSB of L is unset\n";
-	}
-
-	# Store K1 << 1 in K2
-	$k1_bit =~ /^.(.{127})/;
-	$k2_bit = $1.'0';
-	$k2 = pack('B128', $k2_bit);
-
-	# If MSB of K1 == 1, K2 = K2 XOR const_Rb
-	if($k1_bit =~ m/^1/) {
-		#print "MSB of K1 is set\n";
-		$k2 = $k2 ^ $const_rb;
-	} else {
-		#print "MSB of K1 is unset\n";
-	}
-
-	# XOR data with K2
-	$data_expanded ^= $k2;
-
-	# Encrypt data
-	my $cmac = $cipher->encrypt($data_expanded);
-
-	#print "CMAC ".unpack('H32', $cmac)."\n";
-
-	# Extract specified len of MAC
-	my $cmac_pattern = '^(.{'.($cmac_len * 2).'})';
-	unpack('H32', $cmac) =~ /$cmac_pattern/;
-
-	# Return MAC in hexadecimal format
-	return uc($1);
-}
-
-
-sub decodeAFL($$) {
-  my $self = shift;
-  my $afl = shift;
-  my $offset = 0;
-  
-  
-  $self->{afl}{fcl} = unpack('v', $afl);
-  $offset += 2;
-  $self->{afl}{fcl_mf}   = ($self->{afl}{fcl} & 0b0100000000000000) != 0;
-  $self->{afl}{fcl_mclp} = ($self->{afl}{fcl} & 0b0010000000000000) != 0;
-  $self->{afl}{fcl_mlp}  = ($self->{afl}{fcl} & 0b0001000000000000) != 0;
-  $self->{afl}{fcl_mcrp} = ($self->{afl}{fcl} & 0b0000100000000000) != 0;
-  $self->{afl}{fcl_macp} = ($self->{afl}{fcl} & 0b0000010000000000) != 0;
-  $self->{afl}{fcl_kip}  = ($self->{afl}{fcl} & 0b0000001000000000) != 0;
-  $self->{afl}{fcl_fid}  =  $self->{afl}{fcl} & 0b0000000011111111;
-  
-  if ($self->{afl}{fcl_mclp}) {
-    # AFL Message Control Field (AFL.MCL)
-    $self->{afl}{mcl} = unpack('C', substr($afl, $offset, 1));
-    $offset += 1;
-    $self->{afl}{mcl_mlmp} = ($self->{afl}{mcl} & 0b01000000) != 0; 
-    $self->{afl}{mcl_mcmp} = ($self->{afl}{mcl} & 0b00100000) != 0; 
-    $self->{afl}{mcl_kimp} = ($self->{afl}{mcl} & 0b00010000) != 0; 
-    $self->{afl}{mcl_at}   = ($self->{afl}{mcl} & 0b00001111); 
-  }
-  if ($self->{afl}{fcl_mcrp}) {
-    # AFL Message Counter Field (AFL.MCR)
-    $self->{afl}{mcr} = unpack('V', substr($afl, $offset));
-    #printf "AFL MC %08x\n", $self->{afl}{mcr};
-    $offset += 4;
-  }
-  if ($self->{afl}{fcl_mlp}) {
-    # AFL Message Length Field (AFL.ML)
-    $self->{afl}{ml} = unpack('v', substr($afl, $offset));
-    $offset += 2;
-  }
-  if ($self->{afl}{fcl_macp}) {
-    # AFL MAC Field (AFL.MCL)
-    # The length of the MAC field depends on the selected option AFL.MCL.AT indicated by the
-    # AFL.MCL field.
-    my $mac_len = 0;
-    if ($self->{afl}{mcl_at} == 4) {
-      $mac_len = 4;
-      $self->{afl}{mac} = unpack('N', substr($afl, $offset, $mac_len));
-    } elsif ($self->{afl}{mcl_at} == 5) { 
-      $mac_len = 8;
-      $self->{afl}{mac} = (unpack('N', substr($afl, $offset, 4))) << 32 | ((unpack('N', substr($afl, $offset+4, 4))));
-    } elsif ($self->{afl}{mcl_at} == 6) { 
-      $mac_len = 12;
-    } elsif ($self->{afl}{mcl_at} == 7) { 
-      $mac_len = 16;
-    }
-    #printf "AFL MAC %16x\n", $self->{afl}{mac};
-    $offset += $mac_len;
-  }
-  if ($self->{afl}{fcl_kip}) {
-    # AFL Key Information-Field (AFL.KI)
-    $self->{afl}{ki} = unpack('v', $afl);
-    $self->{afl}{ki_key_version}   = ($self->{afl}{ki} & 0b1111111100000000) >> 8;
-    $self->{afl}{ki_kdf_selection} = ($self->{afl}{ki} & 0b0000000001110000) >> 4;
-    $self->{afl}{ki_key_id}        = ($self->{afl}{ki} & 0b0000000000001111);
-    $offset += 2;
-  }
-  return $offset;
-}
-
-sub decodeApplicationLayer($) {
-  my $self = shift;
-  my $applicationlayer = $self->{applicationlayer};
-  my $payload;
-  
-  #print unpack("H*", $applicationlayer) . "\n";
-  
-  if ($self->{errorcode} != ERR_NO_ERROR) {
-    # CRC check failed
-    return 0;
-  }
-  $self->{cifield} = unpack('C', $applicationlayer);
-
-  my $offset = 1;
-
-  if ($self->{cifield} == CI_ELL_2) {
-    # Extended Link Layer
-    ($self->{ell}{cc}, $self->{ell}{access_no}) = unpack('CC', substr($applicationlayer,$offset));
-    $offset += 2;
-  } elsif ($self->{cifield} == CI_ELL_6) {
-    # Extended Link Layer
-    ($self->{ell}{cc}, $self->{ell}{access_no}) = unpack('CC', substr($applicationlayer,$offset));
-    $offset += 6;
-  } elsif ($self->{cifield} == CI_ELL_8) {
-    # Extended Link Layer, payload CRC is part of (encrypted) payload
-    ($self->{ell}{cc}, $self->{ell}{access_no}, $self->{ell}{session_number}) = unpack('CCV', substr($applicationlayer, $offset));
-    $offset += 6;
-  } elsif ($self->{cifield} == CI_ELL_16) {
-    # Extended Link Layer
-    ($self->{ell}{cc}, $self->{ell}{access_no}, $self->{ell}{m2}, $self->{ell}{a2}, $self->{ell}{session_number}) = unpack('CCvC6V', substr($applicationlayer,$offset));
-    $offset += 14;
-  }
-  
-  if (exists($self->{ell}{session_number})) {
-    $self->{ell}{session_number_enc} = $self->{ell}{session_number} >> 29;
-    $self->{ell}{session_number_time} = ($self->{ell}{session_number} & 0b0001111111111111111111111111111) >> 4;
-    $self->{ell}{session_number_session} = $self->{ell}{session_number} & 0b1111;
-    $self->{isEncrypted} = $self->{ell}{session_number_enc} != 0;
-    $self->{decrypted} = 0;
-    
-    if ($self->{isEncrypted}) {
-      if ($self->{aeskey}) {
-        if ($hasCTR) {
-          # AES IV
-          # M-field, A-field, CC, SN, 00, 0000
-          my $initVector = pack("v", $self->{mfield}) . $self->{afield} . pack("CV", $self->{ell}{cc}, $self->{ell}{session_number}) . pack("H*", "000000");
-          my $m = Crypt::Mode::CTR->new('AES', 1);
-          my $ciphertext = substr($applicationlayer,$offset); # payload CRC must also be decrypted
-          #printf("##ciphertext: %s\n", unpack("H*", $ciphertext));
-          $payload = $m->decrypt($ciphertext, $self->{aeskey}, $initVector);
-        
-          #printf("##plaintext   %s\n", unpack("H*", $payload));
-        } else {
-          $self->{errormsg} = 'Crypt::Mode::CTR is not installed, please install it (sudo cpan -i Crypt::Mode::CTR)';
-          $self->{errorcode} = ERR_CIPHER_NOT_INSTALLED;
-          return 0;
-        }
-      } else {
-        $self->{errormsg} = 'encrypted message and no aeskey provided';
-        $self->{errorcode} = ERR_NO_AESKEY;
-        return 0;
-      }
-    }   
-    $self->{ell}{crc} = unpack('v', $payload);
-    $offset += 2;
-    # PayloadCRC is  a  cyclic  redundancy  check  covering  the  remainder  of  the  frame  (excluding the CRC fields)
-    # payload CRC is also encrypted
-    if ($self->{ell}{crc} != $self->calcCRC(substr($payload, 2, $self->{lfield}-20))) {
-      #printf("crc %x, calculated %x\n", $self->{ell}{crc}, $self->calcCRC(substr($payload, 2, $self->{lfield}-20))); 
-      $self->{errormsg} = "Payload CRC check failed on ELL" . ($self->{isEncrypted} ? ", wrong AES key?" : "");
-      $self->{errorcode} = ERR_CRC_FAILED;
-      return 0;
-    } else {
-      $self->{decrypted} = 1;
-    }
-    $applicationlayer = $payload;
-    $offset = 2; # skip PayloadCRC
-  }
-  
-  if ($offset > 1) {
-    $applicationlayer = substr($applicationlayer,$offset);
-    $self->{cifield} = unpack('C', $applicationlayer);
-    $offset = 1;
-    if ($self->{cifield} == CI_AFL) {
-      # Authentification and Fragmentation Layer
-      $self->{afl}{afll} = unpack('C', substr($applicationlayer, $offset));
-      #printf "AFL AFLL %02x\n", $self->{afl}{afll};
-      $offset += 1;
-      $self->decodeAFL(substr($applicationlayer,$offset,$self->{afl}{afll}));
-      $offset += $self->{afl}{afll};
-      if ($self->{afl}{fcl_mf}) {
-        $self->{errormsg} = "fragmented messages are not yet supported";
-        $self->{errorcode} = ERR_FRAGMENT_UNSUPPORTED;
-        return 0;
-      }
-    }
-  }
-  
-  if ($offset > 1) {
-    $applicationlayer = substr($applicationlayer,$offset);
-    $self->{cifield} = unpack('C', $applicationlayer); 
-    $offset = 1;
-  }
-
-  # initialize some fields
-  $self->{cw_1} = 0;
-  $self->{cw_2} = 0;
-  $self->{status} = 0;
-  $self->{statusstring} = "";
-  $self->{access_no} = 0;
-  $self->{sent_from_master} = 0;
-  $self->{isEncrypted} = 0;
-  
-  #printf("CI Field %02x\n", $self->{cifield});
-  
-  if ($self->{cifield} == CI_RESP_4 || $self->{cifield} == CI_RESP_SML_4) {
-    # Short header
-    ($self->{access_no}, $self->{status}, $self->{cw_1}, $self->{cw_2}) = unpack('CCCC', substr($applicationlayer,$offset));
-    #printf("Short header access_no %x\n", $self->{access_no});
-    $offset += 4;
-  } elsif ($self->{cifield} == CI_RESP_12 || $self->{cifield} == CI_RESP_SML_12) {
-    # Long header
-    ($self->{meter_id}, $self->{meter_man}, $self->{meter_vers}, $self->{meter_dev}, $self->{access_no}, $self->{status}, $self->{cw_1}, $self->{cw_2}) 
-      = unpack('VvCCCCCC', substr($applicationlayer,$offset)); 
-    $self->{meter_id} = sprintf("%08d", $self->{meter_id});  
-    $self->{meter_devtypestring} =  $validDeviceTypes{$self->{meter_dev}} || 'unknown'; 
-    $self->{meter_manufacturer} = uc($self->manId2ascii($self->{meter_man}));
-    #printf("Long header access_no %x\n", $self->{access_no});
-    $offset += 12;
-  } elsif ($self->{cifield} == CI_RESP_0) {
-    # no header
-    #print "No header\n";
-
-  } elsif ($self->{cifield} == 0x79 && $self->{manufacturer} eq 'KAM') {
-    #print "Kamstrup compact frame header\n";
-    $self->{format_signature} = unpack("v", substr($applicationlayer,$offset, 2));
-    $offset += 2;
-    $self->{full_frame_payload_crc} = unpack("v", substr($applicationlayer, $offset, 2));
-    $offset += 2;
-    if ($self->{format_signature} == $self->calcCRC(pack("H*", "02FF20" . "0413" . "4413"))) {
-      # Info, Volume, Target Volume
-      # convert into full frame
-      $applicationlayer =   pack("H*", "02FF20") . substr($applicationlayer, 5, 2) # Info
-                          . pack("H*", "0413") . substr($applicationlayer,7,4) # volume
-                          . pack("H*", "4413") . substr($applicationlayer,11,4); # target volume 
-      $offset = 0;
-    } elsif ($self->{format_signature} == $self->calcCRC(pack("H*", "02FF20" . "0413" . "523B"))) {
-      # Info, Volume, Max flow
-      # convert into full frame
-      $applicationlayer =   pack("H*", "02FF20") . substr($applicationlayer, 5, 2) # Info
-                          . pack("H*", "0413") . substr($applicationlayer,7,4) # volume
-                          . pack("H*", "523B") . substr($applicationlayer,11,2); # max flow 
-      $offset = 0;
-    } elsif ($self->{format_signature} == $self->calcCRC(pack("H*", "02FF20" . "0413" . "4413" . "615B" . "6167"))) {
-      # Info, Volume, Max flow, flow temp, external temp
-      # convert into full frame
-      $applicationlayer =   pack("H*", "02FF20") . substr($applicationlayer, 5, 2) # Info
-                          . pack("H*", "0413") . substr($applicationlayer,7,4) # volume
-                          . pack("H*", "4413") . substr($applicationlayer,11,4) # target volume 
-                          . pack("H*", "615B") . substr($applicationlayer,15,1) # flow temp 
-                          . pack("H*", "6167") . substr($applicationlayer,16,1); # external temp
-      $offset = 0;
-    } else {
-      $self->{errormsg} = 'Unknown Kamstrup compact frame format';
-      $self->{errorcode} = ERR_UNKNOWN_COMPACT_FORMAT;
-      return 0;
-    }
-    if ($self->{full_frame_payload_crc} != $self->calcCRC($applicationlayer)) {
-      $self->{errormsg} = 'Kamstrup compact frame format payload CRC error';
-      $self->{errorcode} = ERR_CRC_FAILED;
-      return 0;
-    }
-  } elsif ($self->{cifield} == CI_SND_UD_MODE_1 || $self->{cifield} == CI_SND_UD_MODE_2) {
-    $self->{sent_from_master} = 1;
-    # The  EN1434-3  defines  two  possible  data  sequences  in  multibyte  records.  
-    # The  bit  two (counting begins with bit 0, value 4), which is called M bit or Mode bit, 
-    # in the CI field gives an  information  about  the  used  byte  sequence  in  multibyte  data  structures.  
-    # If  the  Mode  bit  is not set (Mode 1), the least significant byte of a multibyte record is transmitted first, 
-    # otherwise (Mode  2)  the  most  significant  byte.  
-    # The  Usergroup  recommends  to  use  only  the  Mode  1  in future applications.
-    $self->{mode_bit} = $self->{cifield} & 4; 
-  } else {
-    # unsupported
-    $self->decodeConfigword();
-    $self->{errormsg} = 'Unsupported CI Field ' . sprintf("%x", $self->{cifield}) . ", remaining payload is " . unpack("H*", substr($applicationlayer,$offset));
-    $self->{errorcode} = ERR_UNKNOWN_CIFIELD;
-    return 0;
-  }
-  $self->{statusstring} = join(", ", $self->state2string($self->{status}));
-
-  $self->decodeConfigword();
-  
-  $self->{encryptionMode} = $encryptionModes{$self->{cw_parts}{mode}};
-  if ($self->{cw_parts}{mode} == 0) {
-    # no encryption
-    if (!$self->{isEncrypted}) {
-      $self->{decrypted} = 1;
-    }
-    $payload = substr($applicationlayer, $offset);
-  } elsif ($self->{cw_parts}{mode} == 5) {
-    # data is encrypted with AES 128, dynamic init vector
-    # decrypt data before further processing
-    $self->{isEncrypted} = 1;
-    $self->{decrypted} = 0;
-
-    if ($self->{aeskey}) { 
-      if ($hasCBC) {
-        my $encrypted_length = $self->{cw_parts}{encrypted_blocks} * 16;
-        #printf("encrypted payload %s\n", unpack("H*", substr($applicationlayer,$offset, $encrypted_length)));
-        eval {
-          $payload = $self->decrypt(substr($applicationlayer, $offset, $encrypted_length)) 
-            . substr($applicationlayer, $offset+$encrypted_length);
-        };
-        if ($@) {
-          #fatal decryption error occurred
-          $self->{errormsg} = "fatal decryption error: $@";
-          $self->{errorcode} = ERR_DECRYPTION_FAILED;
-          return 0;
-        }
-        #printf("decrypted payload %s\n", unpack("H*", $payload));
-        if (unpack('n', $payload) == 0x2f2f) {
-          $self->{decrypted} = 1;
-        } else {
-          # Decryption verification failed
-          $self->{errormsg} = 'Decryption failed, wrong key?';
-          $self->{errorcode} = ERR_DECRYPTION_FAILED;
-          #printf("%x\n", unpack('n', $payload));
-          return 0;
-        }
-      } else {
-        $self->{errormsg} = 'Crypt::Mode::CBC is not installed, please install it (sudo cpan -i Crypt::Mode::CBC)';
-        $self->{errorcode} = ERR_CIPHER_NOT_INSTALLED;
-        return 0;
-      }
-    } else {
-      $self->{errormsg} = 'encrypted message and no aeskey provided';
-      $self->{errorcode} = ERR_NO_AESKEY;
-      return 0;
-    }
-
-  } else {
-    # error, encryption mode not implemented
-    $self->{errormsg} = sprintf('Encryption mode %x not implemented', $self->{cw_parts}{mode});
-    $self->{errorcode} = ERR_UNKNOWN_ENCRYPTION;
-    $self->{isEncrypted} = 1;
-    $self->{decrypted} = 0;
-    return 0;
-  }
-  
-  if ($self->{cifield} == CI_RESP_SML_4 || $self->{cifield} == CI_RESP_SML_12) {
-    # payload is SML encoded, that's not implemented
-    $self->{errormsg} = "payload is SML encoded, can't be decoded, SML payload is " . unpack("H*", substr($applicationlayer,$offset));
-    $self->{errorcode} = ERR_SML_PAYLOAD;
-    return 0;
-  } else {
-    return $self->decodePayload($payload);  
-  }
-  
-}
-
-sub decodeLinkLayer($$)
-{
-  my $self = shift;
-  my $linklayer = shift;
-
-  if (length($linklayer) < TL_BLOCK_SIZE + $self->{crc_size}) {
-    $self->{errormsg} = "link layer too short";
-    $self->{errorcode} = ERR_LINK_LAYER_INVALID;
-    return 0;
-  }
-  ($self->{lfield}, $self->{cfield}, $self->{mfield}) = unpack('CCv', $linklayer);
-  $self->{afield} = substr($linklayer,4,6);
-  $self->{afield_id} = sprintf("%08d", $self->decodeBCD(8,substr($linklayer,4,4)));
-  ($self->{afield_ver}, $self->{afield_type}) = unpack('CC', substr($linklayer,8,2));
-  
-  #printf("lfield %d\n", $self->{lfield});
-
-  if ($self->{frame_type} eq FRAME_TYPE_A) {
-    if ($self->{crc_size} > 0) {
-      $self->{crc0} = unpack('n', substr($linklayer,TL_BLOCK_SIZE, $self->{crc_size}));
-    
-      #printf("crc0 %x calc %x\n", $self->{crc0}, $self->calcCRC(substr($linklayer,0,10)));
-    
-      if ($self->{crc0} != $self->calcCRC(substr($linklayer,0,TL_BLOCK_SIZE))) {
-        $self->{errormsg} = "CRC check failed on link layer";
-        $self->{errorcode} = ERR_CRC_FAILED;
-        #print "CRC check failed on link layer\n";
-        return 0;
-      }
-    }
-
-    # header block is 10 bytes + 2 bytes CRC, each following block is 16 bytes + 2 bytes CRC, the last block may be smaller
-    $self->{datalen} = $self->{lfield} - (TL_BLOCK_SIZE - 1); # this is without CRCs and the lfield itself
-    $self->{datablocks} = int($self->{datalen} / LL_BLOCK_SIZE);
-    $self->{datablocks}++ if $self->{datalen} % LL_BLOCK_SIZE != 0;
-    $self->{msglen} = TL_BLOCK_SIZE + $self->{crc_size} + $self->{datalen} + $self->{datablocks} * $self->{crc_size};
-      
-    #printf("calc len %d, actual %d\n", $self->{msglen}, length($self->{msg}));
-    $self->{applicationlayer} = $self->removeCRC(substr($self->{msg},TL_BLOCK_SIZE + $self->{crc_size}));
-  
-  } else {
-    # FRAME TYPE B
-    # each block is at most 129 bytes long.
-    # first contains the header (TL_BLOCK), L field and trailing crc
-    # L field is included in crc calculation
-    # each following block contains only data and trailing crc
-    if (length($self->{msg}) < $self->{lfield}) {
-      $self->{errormsg} = "message too short, expected " . $self->{lfield} . ", got " . length($self->{msg}) . " bytes";
-      $self->{errorcode} = ERR_MSG_TOO_SHORT;
-      return 0;
-    }    
-    
-    
-    my $length = 129;
-    if ($self->{lfield} < $length) {
-      $length = $self->{lfield};
-    }
-    if ($self->{crc_size} > 0) {
-      $length -= $self->{crc_size};
-      $length++; # for L field
-      #print "length: $length\n";
-      $self->{crc0} = unpack('n', substr($self->{msg}, $length, $self->{crc_size}));
-      
-      #printf "crc in msg %x crc calculated %x\n", $self->{crc0}, $self->calcCRC(substr($self->{msg}, 0, $length));
-      if ($self->{crc0} != $self->calcCRC(substr($self->{msg}, 0, $length))) {
-        $self->{errormsg} = "CRC check failed on block 1";
-        $self->{errorcode} = ERR_CRC_FAILED;
-        return 0;
-      }
-    }
-    
-    $self->{datablocks} = int($self->{lfield} / 129);
-    $self->{datablocks}++ if $self->{lfield} % 129 != 0;
-    # header block is 10 bytes, following block 
-    $self->{datalen} = $self->{lfield} - (TL_BLOCK_SIZE - 1) - ($self->{datablocks} * $self->{crc_size}) ; # this is with CRCs but without the lfield itself
-    $self->{msglen} = $self->{lfield};
-
-    if ($self->{datablocks} == 2) {
-      # TODO
-    } else {
-      $self->{applicationlayer} = substr($self->{msg}, TL_BLOCK_SIZE, $length - TL_BLOCK_SIZE); # - $self->{crc_size});
-    }
-  }
-
-  if (length($self->{msg}) > $self->{msglen}) {
-    $self->{remainingData} = substr($self->{msg},$self->{msglen});
-  } elsif (length($self->{msg}) < $self->{msglen}) {
-    $self->{errormsg} = "message too short, expected " . $self->{msglen} . ", got " . length($self->{msg}) . " bytes";
-    $self->{errorcode} = ERR_MSG_TOO_SHORT;
-    return 0;
-  }
-  
-  
-  # according to the MBus spec only upper case letters are allowed.
-  # some devices send lower case letters none the less
-  # convert to upper case to make them spec conformant
-  $self->{manufacturer} = uc($self->manId2ascii($self->{mfield}));
-  $self->{typestring} =  $validDeviceTypes{$self->{afield_type}} || 'unknown';
-  return 1;
-}
-
-sub encodeLinkLayer($)
-{
-  my $self = shift;
-
-  my $linklayer = pack('CCv', $self->{lfield}, $self->{cfield}, $self->{mfield});
-  ($self->{lfield}, $self->{cfield}, $self->{mfield}) = unpack('CCv', $linklayer);
-  $self->{afield} = substr($linklayer,4,6);
-  $self->{afield_id} = sprintf("%08d", $self->decodeBCD(8,substr($linklayer,4,4)));
-  ($self->{afield_ver}, $self->{afield_type}) = unpack('CC', substr($linklayer,8,2));
-  
-  #printf("lfield %d\n", $self->{lfield});
-
-  if ($self->{frame_type} eq FRAME_TYPE_A) {
-    if ($self->{crc_size} > 0) {
-      $self->{crc0} = unpack('n', substr($linklayer,TL_BLOCK_SIZE, $self->{crc_size}));
-    
-      #printf("crc0 %x calc %x\n", $self->{crc0}, $self->calcCRC(substr($linklayer,0,10)));
-    
-      if ($self->{crc0} != $self->calcCRC(substr($linklayer,0,TL_BLOCK_SIZE))) {
-        $self->{errormsg} = "CRC check failed on link layer";
-        $self->{errorcode} = ERR_CRC_FAILED;
-        #print "CRC check failed on link layer\n";
-        return 0;
-      }
-    }
-
-    # header block is 10 bytes + 2 bytes CRC, each following block is 16 bytes + 2 bytes CRC, the last block may be smaller
-    $self->{datalen} = $self->{lfield} - (TL_BLOCK_SIZE - 1); # this is without CRCs and the lfield itself
-    $self->{datablocks} = int($self->{datalen} / LL_BLOCK_SIZE);
-    $self->{datablocks}++ if $self->{datalen} % LL_BLOCK_SIZE != 0;
-    $self->{msglen} = TL_BLOCK_SIZE + $self->{crc_size} + $self->{datalen} + $self->{datablocks} * $self->{crc_size};
-      
-    #printf("calc len %d, actual %d\n", $self->{msglen}, length($self->{msg}));
-    $self->{applicationlayer} = $self->removeCRC(substr($self->{msg},TL_BLOCK_SIZE + $self->{crc_size}));
-  
-  } else {
-    # FRAME TYPE B
-    # each block is at most 129 bytes long.
-    # first contains the header (TL_BLOCK), L field and trailing crc
-    # L field is included in crc calculation
-    # each following block contains only data and trailing crc
-    if (length($self->{msg}) < $self->{lfield}) {
-      $self->{errormsg} = "message too short, expected " . $self->{lfield} . ", got " . length($self->{msg}) . " bytes";
-      $self->{errorcode} = ERR_MSG_TOO_SHORT;
-      return 0;
-    }    
-    
-    
-    my $length = 129;
-    if ($self->{lfield} < $length) {
-      $length = $self->{lfield};
-    }
-    if ($self->{crc_size} > 0) {
-      $length -= $self->{crc_size};
-      $length++; # for L field
-      #print "length: $length\n";
-      $self->{crc0} = unpack('n', substr($self->{msg}, $length, $self->{crc_size}));
-      
-      #printf "crc in msg %x crc calculated %x\n", $self->{crc0}, $self->calcCRC(substr($self->{msg}, 0, $length));
-      if ($self->{crc0} != $self->calcCRC(substr($self->{msg}, 0, $length))) {
-        $self->{errormsg} = "CRC check failed on block 1";
-        $self->{errorcode} = ERR_CRC_FAILED;
-        return 0;
-      }
-    }
-    
-    $self->{datablocks} = int($self->{lfield} / 129);
-    $self->{datablocks}++ if $self->{lfield} % 129 != 0;
-    # header block is 10 bytes, following block 
-    $self->{datalen} = $self->{lfield} - (TL_BLOCK_SIZE - 1) - ($self->{datablocks} * $self->{crc_size}) ; # this is with CRCs but without the lfield itself
-    $self->{msglen} = $self->{lfield};
-
-    if ($self->{datablocks} == 2) {
-      # TODO
-    } else {
-      $self->{applicationlayer} = substr($self->{msg}, TL_BLOCK_SIZE, $length - TL_BLOCK_SIZE); # - $self->{crc_size});
-    }
-  }
-
-  if (length($self->{msg}) > $self->{msglen}) {
-    $self->{remainingData} = substr($self->{msg},$self->{msglen});
-  } elsif (length($self->{msg}) < $self->{msglen}) {
-    $self->{errormsg} = "message too short, expected " . $self->{msglen} . ", got " . length($self->{msg}) . " bytes";
-    $self->{errorcode} = ERR_MSG_TOO_SHORT;
-    return 0;
-  }
-  
-  
-  # according to the MBus spec only upper case letters are allowed.
-  # some devices send lower case letters none the less
-  # convert to upper case to make them spec conformant
-  $self->{manufacturer} = uc($self->manId2ascii($self->{mfield}));
-  $self->{typestring} =  $validDeviceTypes{$self->{afield_type}} || 'unknown';
-  return 1;
-}
-
-
-sub setFrameType($$)
-{
-  my $self = shift;
-  $self->{frame_type} = shift;
-}
-
-sub getFrameType($)
-{
-  my $self = shift;
-  return $self->{frame_type};
-}
-
-sub parse($$)
-{
-  my $self = shift;
-  $self->{msg} = shift;
-  
-  $self->{errormsg} = '';
-  $self->{errorcode} = ERR_NO_ERROR;
-  
-  if (length($self->{msg}) < 12) {
-    $self->{errormsg} = "Message too short";
-    $self->{errorcode} = ERR_MSG_TOO_SHORT;
-    return 1;
-  }
-  if (substr($self->{msg}, 0, 4) eq pack("H*", "543D543D")) {
-    $self->setFrameType(FRAME_TYPE_B);
-    $self->{msg} = substr($self->{msg},4);
-  }
-  if ($self->decodeLinkLayer(substr($self->{msg},0,12)) != 0)  {
-    $self->{linkLayerOk} = 1;
-    return $self->decodeApplicationLayer();
-  }
-  return 0;
-
-}
-
-sub parseLinkLayer($$)
-{
-  my $self = shift;
-  $self->{msg} = shift;
-
-  $self->{errormsg} = '';
-  $self->{errorcode} = ERR_NO_ERROR;
-  $self->{linkLayerOk} = $self->decodeLinkLayer(substr($self->{msg},0,12));
-  return $self->{linkLayerOk};
-}
-
-sub parseApplicationLayer($)
-{
-  my $self = shift;
-
-  $self->{errormsg} = '';
-  $self->{errorcode} = ERR_NO_ERROR;
-  return $self->decodeApplicationLayer();
-}
-
-1;
+# $Id$
+
+package WMBus;
+
+use strict;
+use warnings;
+use feature qw(say);
+use Scalar::Util qw(looks_like_number);
+use Digest::CRC; # libdigest-crc-perl
+eval "use Crypt::Mode::CBC"; # cpan -i Crypt::Mode::CBC
+my $hasCBC = ($@)?0:1;
+eval "use Crypt::Mode::CTR"; # cpan -i Crypt::Mode::CTR
+my $hasCTR = ($@)?0:1;
+eval "use Digest::CMAC"; # cpan -i Digest::CMAC
+my $hasCMAC = ($@)?0:1;
+
+require Exporter;
+my @ISA = qw(Exporter);
+my @EXPORT = qw(new parse parseLinkLayer parseApplicationLayer manId2ascii type2string setFrameType getFrameType VIF_TYPE_MANUFACTURER_SPECIFIC);
+
+sub manId2ascii($$);
+
+
+use constant {
+  # Transport Layer block size
+  TL_BLOCK_SIZE => 10,
+  # Link Layer block size
+  LL_BLOCK_SIZE => 16,
+  # size of CRC in bytes
+  CRC_SIZE => 2,
+
+  # sent by meter
+  SND_NR => 0x44, # Send, no reply
+  SND_IR => 0x46, # Send installation request, must reply with CNF_IR
+  ACC_NR => 0x47,
+  ACC_DMD => 0x48,
+  
+  # sent by controller
+  SND_NKE => 0x40, # Link reset
+  CNF_IR => 0x06, 
+  
+  # CI field
+  CI_RESP_4 => 0x7a,  # Response from device, 4 Bytes
+  CI_RESP_12 => 0x72, # Response from device, 12 Bytes
+  CI_RESP_0 => 0x78,  # Response from device, 0 Byte header, variable length
+  CI_ERROR => 0x70,   # Error from device, only specified for wired M-Bus but used by Easymeter WMBUS module
+  CI_TL_4 => 0x8a,    # Transport layer from device, 4 Bytes
+  CI_TL_12 => 0x8b,   # Transport layer from device, 12 Bytes
+  CI_ELL_2 => 0x8c,   # Extended Link Layer, 2 Bytes
+  CI_ELL_6 => 0x8e,   # Extended Link Layer, 6 Bytes
+  CI_ELL_8 => 0x8d,   # Extended Link Layer, 8 Bytes (see https://www.telit.com/wp-content/uploads/2017/09/Telit_Wireless_M-bus_2013_Part4_User_Guide_r14.pdf, 2.3.4)
+  CI_ELL_16 => 0x8f,  # Extended Link Layer, 16 Bytes (see https://www.telit.com/wp-content/uploads/2017/09/Telit_Wireless_M-bus_2013_Part4_User_Guide_r14.pdf, 2.3.4)
+  CI_AFL => 0x90,     # Authentification and Fragmentation Layer, variable size
+  CI_RESP_SML_4 => 0x7e, # Response from device, 4 Bytes, application layer SML encoded
+  CI_RESP_SML_12 => 0x7f, # Response from device, 12 Bytes, application layer SML encoded  
+  CI_SND_UD_MODE_1 => 0x51, # The master can send data to a slave using a SND_UD with CI-Field 51h for mode 1 or 55h for mode 2
+  CI_SND_UD_MODE_2 => 0x55,
+  
+  # DIF types (Data Information Field), see page 32
+  DIF_NONE => 0x00,
+  DIF_INT8 => 0x01,
+  DIF_INT16 => 0x02,
+  DIF_INT24 => 0x03,
+  DIF_INT32 => 0x04,
+  DIF_FLOAT32 => 0x05,
+  DIF_INT48 => 0x06,
+  DIF_INT64 => 0x07,
+  DIF_READOUT => 0x08,
+  DIF_BCD2 => 0x09,
+  DIF_BCD4 => 0x0a,
+  DIF_BCD6 => 0x0b,
+  DIF_BCD8 => 0x0c,
+  DIF_VARLEN => 0x0d,
+  DIF_BCD12 => 0x0e,
+  DIF_SPECIAL => 0x0f,
+
+  
+  DIF_IDLE_FILLER => 0x2f,
+  
+  DIF_EXTENSION_BIT => 0x80,
+  
+  VIF_EXTENSION        => 0xFB,                     # true VIF is given in the first VIFE and is coded using table 8.4.4 b) (128 new VIF-Codes)
+  VIF_EXTENSION_BIT    => 0x80,
+  
+
+  ERR_NO_ERROR => 0,
+  ERR_CRC_FAILED => 1,
+  ERR_UNKNOWN_VIFE => 2,
+  ERR_UNKNOWN_VIF => 3,
+  ERR_TOO_MANY_DIFE => 4,
+  ERR_UNKNOWN_LVAR => 5,
+  ERR_UNKNOWN_DATAFIELD => 6,
+  ERR_UNKNOWN_CIFIELD => 7,
+  ERR_DECRYPTION_FAILED => 8,
+  ERR_NO_AESKEY => 9,
+  ERR_UNKNOWN_ENCRYPTION => 10,
+  ERR_TOO_MANY_VIFE => 11,
+  ERR_MSG_TOO_SHORT => 12,
+  ERR_SML_PAYLOAD => 13,
+  ERR_FRAGMENT_UNSUPPORTED => 14,
+  ERR_UNKNOWN_COMPACT_FORMAT => 15,
+  ERR_CIPHER_NOT_INSTALLED => 16,
+  ERR_LINK_LAYER_INVALID => 17,
+  
+  VIF_TYPE_MANUFACTURER_SPECIFIC => 'MANUFACTURER SPECIFIC',
+ 
+  # TYPE C transmission uses two different frame types
+  # see http://www.st.com/content/ccc/resource/technical/document/application_note/3f/fb/35/5a/25/4e/41/ba/DM00233038.pdf/files/DM00233038.pdf/jcr:content/translations/en.DM00233038.pdf
+  FRAME_TYPE_A => 'A',
+  FRAME_TYPE_B => 'B',
+  
+};
+
+sub valueCalcNumeric($$) {
+  my $value = shift;
+  my $dataBlock = shift;
+
+  # some sanity checks on the provided data
+  if (defined($value) && defined($dataBlock->{valueFactor}) && looks_like_number($value))
+  {
+    return $value * $dataBlock->{valueFactor};
+  } else {
+    return 0;
+  }
+  
+}
+
+sub valueCalcDate($$) {
+  my $value = shift;
+  my $dataBlock = shift;
+  
+  #value is a 16bit int
+  
+  #day: UI5 [1 to 5] <1 to 31>
+  #month: UI4 [9 to 12] <1 to 12>
+  #year: UI7[6 to 8,13 to 16] <0 to 99>
+  
+  #   YYYY MMMM YYY DDDDD
+  # 0b0000 1100 111 11111 = 31.12.2007
+  # 0b0000 0100 111 11110 = 30.04.2007
+
+  my $day = ($value & 0b11111);
+  my $month = (($value & 0b111100000000) >> 8);
+  my $year = ((($value & 0b1111000000000000) >> 9) | (($value & 0b11100000) >> 5)) + 2000;
+  if ($day > 31 || $month > 12 || $year > 2099) {
+    return sprintf("invalid: %x", $value);
+  } else {
+    return sprintf("%04d-%02d-%02d", $year, $month, $day);
+  }
+}
+
+sub valueCalcDateTime($$) {
+  my $value = shift;
+  my $dataBlock = shift;
+
+#min: UI6 [1 to 6] <0 to 59>
+#hour: UI5 [9 to13] <0 to 23>
+#day: UI5 [17 to 21] <1 to 31>
+#month: UI4 [25 to 28] <1 to 12>
+#year: UI7[22 to 24,29 to 32] <0 to 99>
+# IV:
+# B1[8] {time invalid}:
+# IV<0> :=
+#valid,
+#IV>1> := invalid
+#SU: B1[16] {summer time}:
+#SU<0> := standard time,
+#SU<1> := summer time
+#RES1: B1[7] {reserved}: <0>
+#RES2: B1[14] {reserved}: <0>
+#RES3: B1[15] {reserved}: <0>
+  
+  
+  my $datePart = $value >> 16;
+  my $timeInvalid = $value & 0b10000000;
+  
+  my $dateTime = valueCalcDate($datePart, $dataBlock);
+  if ($timeInvalid == 0) {
+    my $min = ($value & 0b111111);
+    my $hour = ($value >> 8) & 0b11111;
+    my $su = ($value & 0b1000000000000000);
+    if ($min > 59 || $hour > 23) {
+      $dateTime = sprintf('invalid: %x', $value);
+    } else {
+      $dateTime .= sprintf(' %02d:%02d %s', $hour, $min, $su ? 'DST' : '');
+    }
+  }
+  
+  return $dateTime;  
+}
+
+sub valueCalcHex($$) {
+  my $value = shift;
+  my $dataBlock = shift;
+
+  return sprintf("%x", $value);
+}
+
+sub valueCalcu($$) {
+  my $value = shift;
+  my $dataBlock = shift;
+
+  my $result = '';
+  
+  $result = ($value & 0b00001000 ? 'upper' : 'lower') . ' limit';
+  return $result;
+}
+
+sub valueCalcufnn($$) {
+  my $value = shift;
+  my $dataBlock = shift;
+
+  my $result = '';
+  
+  $result = ($value & 0b00001000 ? 'upper' : 'lower') . ' limit';
+  $result .= ', ' . ($value & 0b00000100 ? 'first' : 'last');
+  $result .= sprintf(', duration %d', $value & 0b11);
+  return $result;
+}
+
+sub valueCalcMultCorr1000($$) {
+  my $value = shift;
+  my $dataBlock = shift;
+  
+  $dataBlock->{value} *= 1000;
+
+  return "correction by factor 1000";
+}
+
+
+my %TimeSpec = (
+  0b00 => 's', # seconds
+  0b01 => 'm', # minutes
+  0b10 => 'h', # hours
+  0b11 => 'd', # days
+);
+
+sub valueCalcTimeperiod($$) {
+  my $value = shift;
+  my $dataBlock = shift;
+  
+  $dataBlock->{unit} = $TimeSpec{$dataBlock->{exponent}};
+  return $value;
+}
+
+# VIF types (Value Information Field), see page 32
+my %VIFInfo = (
+  VIF_ENERGY_WATT  => {                     #  10(nnn-3) Wh  0.001Wh to 10000Wh
+    typeMask     => 0b01111000,
+    expMask      => 0b00000111,
+    type         => 0b00000000,
+    bias         => -3,
+    unit         => 'Wh',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_ENERGY_JOULE   => {                     #  10(nnn) J     0.001kJ to 10000kJ
+    typeMask     => 0b01111000,
+    expMask      => 0b00000111,
+    type         => 0b00001000,
+    bias         => 0,
+    unit         => 'J',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_VOLUME           => {                     #  10(nnn-6) m3  0.001l to 10000l
+    typeMask     => 0b01111000,
+    expMask      => 0b00000111,
+    type         => 0b00010000,
+    bias         => -6,
+    unit         => 'm³',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_MASS             => {                     #  10(nnn-3) kg  0.001kg to 10000kg
+    typeMask     => 0b01111000,
+    expMask      => 0b00000111,
+    type         => 0b00011000,
+    bias         => -3,
+    unit         => 'kg',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_ON_TIME_SEC      => {                     #  seconds
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100000,
+    bias         => 0,
+    unit         => 'sec',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_ON_TIME_MIN      => {                     #  minutes
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100001,
+    bias         => 0,
+    unit         => 'min',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_ON_TIME_HOURS    => {                     #  hours
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100010,
+    bias         => 0,
+    unit         => 'hours',
+  },
+  VIF_ON_TIME_DAYS    => {                     #  days
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100011,
+    bias         => 0,
+    unit         => 'days',
+  },
+  VIF_OP_TIME_SEC      => {                     #  seconds
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100100,
+    bias         => 0,
+    unit         => 'sec',
+  },
+  VIF_OP_TIME_MIN      => {                     #  minutes
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100101,
+    bias         => 0,
+    unit         => 'min',
+  },
+  VIF_OP_TIME_HOURS    => {                     #  hours
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100110,
+    bias         => 0,
+    unit         => 'hours',
+  },
+  VIF_OP_TIME_DAYS    => {                     #  days
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100111,
+    bias         => 0,
+    unit         => 'days',
+  },
+  VIF_ELECTRIC_POWER   => {                     #  10(nnn-3) W   0.001W to 10000W
+    typeMask     => 0b01111000,
+    expMask      => 0b00000111,
+    type         => 0b00101000,
+    bias         => -3,
+    unit         => 'W',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_THERMAL_POWER    =>  {                    #  10(nnn) J/h   0.001kJ/h to 10000kJ/h
+    typeMask     => 0b01111000,
+    expMask      => 0b00000111,
+    type         => 0b00110000,
+    bias         => 0,
+    unit         => 'J/h',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_VOLUME_FLOW      => {                     #  10(nnn-6) m3/h 0.001l/h to 10000l/h
+    typeMask     => 0b01111000,
+    expMask      => 0b00000111,
+    type         => 0b00111000,
+    bias         => -6,
+    unit         => 'm³/h',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_VOLUME_FLOW_EXT1 => {                     #  10(nnn-7) m3/min 0.0001l/min to 10000l/min
+    typeMask     => 0b01111000,
+    expMask      => 0b00000111,
+    type         => 0b01000000,
+    bias         => -7,
+    unit         => 'm³/min',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_VOLUME_FLOW_EXT2 => {                     #  10(nnn-9) m3/s 0.001ml/s to 10000ml/s
+    typeMask     => 0b01111000,
+    expMask      => 0b00000111,
+    type         => 0b01001000,
+    bias         => -9,
+    unit         => 'm³/s',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_MASS_FLOW         => {                   #  10(nnn-3) kg/h 0.001kg/h to 10000kg/h
+    typeMask     => 0b01111000,
+    expMask      => 0b00000111,
+    type         => 0b01010000,
+    bias         => -3,
+    unit         => 'kg/h',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_FLOW_TEMP         => {                   #  10(nn-3) °C 0.001°C to 1°C
+    typeMask     => 0b01111100,
+    expMask      => 0b00000011,
+    type         => 0b01011000,
+    bias         => -3,
+    unit         => '°C',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_RETURN_TEMP       => {                   #  10(nn-3) °C 0.001°C to 1°C
+    typeMask     => 0b01111100,
+    expMask      => 0b00000011,
+    type         => 0b01011100,
+    bias         => -3,
+    unit         => '°C',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_TEMP_DIFF        => {                    #  10(nn-3) K 1mK to 1000mK
+    typeMask     => 0b01111100,
+    expMask      => 0b00000011,
+    type         => 0b01100000,
+    bias         => -3,
+    unit         => 'K',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_EXTERNAL_TEMP    => {                   #  10(nn-3) °C 0.001°C to 1°C
+    typeMask     => 0b01111100,
+    expMask      => 0b00000011,
+    type         => 0b01100100,
+    bias         => -3,
+    unit         => '°C',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_PRESSURE    => {                        #  10(nn-3) bar  1mbar to 1000mbar
+    typeMask     => 0b01111100,
+    expMask      => 0b00000011,
+    type         => 0b01101000,
+    bias         => -3,
+    unit         => 'bar',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_TIME_POINT_DATE => {                    #  data type G
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01101100,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcDate,
+  },
+  VIF_TIME_POINT_DATE_TIME => {               #  data type F
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01101101,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcDateTime,
+  },
+  VIF_HCA              =>  {                  # Unit for Heat Cost Allocator, dimensonless
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01101110,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_FABRICATION_NO =>  {                    # Fabrication No
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01111000,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_OWNER_NO =>  {                          # Eigentumsnummer (used by Easymeter even though the standard allows this only for writing to a slave)
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01111001,
+    bias         => 0,
+    unit         => '',
+  },  
+  VIF_AVERAGING_DURATION_SEC      => {                     #  seconds
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01110000,
+    bias         => 0,
+    unit         => 'sec',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_AVERAGING_DURATION_MIN      => {                     #  minutes
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01110001,
+    bias         => 0,
+    unit         => 'min',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_AVERAGING_DURATION_HOURS    => {                     #  hours
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01110010,
+    bias         => 0,
+    unit         => 'hours',
+  },
+  VIF_AVERAGING_DURATION_DAYS    => {                     #  days
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01110011,
+    bias         => 0,
+    unit         => 'days',
+  },  
+  VIF_ACTUALITY_DURATION_SEC      => {                     #  seconds
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01110100,
+    bias         => 0,
+    unit         => 'sec',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_ACTUALITY_DURATION_MIN      => {                     #  minutes
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01110101,
+    bias         => 0,
+    unit         => 'min',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_ACTUALITY_DURATION_HOURS    => {                     #  hours
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01110110,
+    bias         => 0,
+    unit         => 'hours',
+  },
+  VIF_ACTUALITY_DURATION_DAYS    => {                     #  days
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01110111,
+    bias         => 0,
+    unit         => 'days',
+  },  
+);  
+
+# Codes used with extension indicator $FD, see 8.4.4 on page 80
+my %VIFInfo_FD = (  
+  VIF_CREDIT  => {                        #  Credit of 10nn-3 of the nominal local legal currency units
+    typeMask     => 0b01111100,
+    expMask      => 0b00000011,
+    type         => 0b00000000,
+    bias         => -3,
+    unit         => '€',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_DEBIT  => {                         #  Debit of 10nn-3 of the nominal local legal currency units
+    typeMask     => 0b01111100,
+    expMask      => 0b00000011,
+    type         => 0b00000100,
+    bias         => -3,
+    unit         => '€',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_ACCESS_NO  => {                     #  Access number (transmission count)
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00001000,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_MEDIUM  => {                        #  Medium (as in fixed header)
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00001001,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_MANUFACTURER  => {                  #  Manufacturer (as in fixed header)
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00001010,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_PARAMETER_SET_ID  => {             #  Parameter set identification
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00001011,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_MODEL_VERSION => {                  #  Model / Version
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00001100,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_HARDWARE_VERSION => {               #  Hardware version #
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00001101,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_FIRMWARE_VERSION => {               #  Firmware version #
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00001110,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_SOFTWARE_VERSION => {               #  Software version #
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00001111,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_ERROR_FLAGS => {                    #  Error flags (binary)
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00010111,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcHex,
+  },
+  VIF_DURATION_SINCE_LAST_READOUT => {    #   Duration since last readout [sec(s)..day(s)]
+    typeMask     => 0b01111100,
+    expMask      => 0b00000011,
+    type         => 0b00101100,
+    bias         => 0,
+    unit         => 's',
+    calcFunc     => \&valueCalcTimeperiod,
+  },
+  VIF_VOLTAGE => {                        #  10nnnn-9 Volts
+    typeMask     => 0b01110000,
+    expMask      => 0b00001111,
+    type         => 0b01000000,
+    bias         => -9,
+    unit         => 'V',
+    calcFunc     => \&valueCalcNumeric,
+  },  
+  VIF_ELECTRICAL_CURRENT => {             #  10nnnn-12 Ampere
+    typeMask     => 0b01110000,
+    expMask      => 0b00001111,
+    type         => 0b01010000,
+    bias         => -12,
+    unit         => 'A',
+    calcFunc     => \&valueCalcNumeric,
+  },  
+  VIF_RECEPTION_LEVEL => {                #   reception level of a received radio device.
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01110001,
+    bias         => 0,
+    unit         => 'dBm',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_STATE_PARAMETER_ACTIVATION => {     #  State of parameter activation
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01100110,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_SPECIAL_SUPPLIER_INFORMATION => {     #  Special supplier information
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01100111,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  
+  VIF_FD_RESERVED => {                   # Reserved
+    typeMask     => 0b01110000,
+    expMask      => 0b00000000,
+    type         => 0b01110000,
+    bias         => 0,
+    unit         => 'Reserved',
+  },
+  
+);
+
+# Codes used with extension indicator $FB
+my %VIFInfo_FB = (                              
+  VIF_ENERGY  => {                     #  Energy 10(n-1) MWh  0.1MWh to 1MWh
+    typeMask     => 0b01111110,
+    expMask      => 0b00000001,
+    type         => 0b00000000,
+    bias         => -1,
+    unit         => 'MWh',
+    calcFunc     => \&valueCalcNumeric,
+  },
+);
+
+
+# Codes used for an enhancement of VIFs other than $FD and $FB
+my %VIFInfo_other = (       
+  VIF_ERROR_NONE => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00000000,
+    bias         => 0,
+    unit         => 'No error',
+  },
+  VIF_TOO_MANY_DIFES => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00000001,
+    bias         => 0,
+    unit         => 'Too many DIFEs',
+  },
+
+  VIF_ILLEGAL_VIF_GROUP => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00001100,
+    bias         => 0,
+    unit         => 'Illegal VIF-Group',
+  },
+
+  VIF_DATA_UNDERFLOW => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00010111,
+    bias         => 0,
+    unit         => 'Data underflow',
+  },
+
+
+  VIF_PER_SECOND => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100000,
+    bias         => 0,
+    unit         => 'per second',
+  },
+  VIF_PER_MINUTE => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100001,
+    bias         => 0,
+    unit         => 'per minute',
+  },
+  VIF_PER_HOUR => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100010,
+    bias         => 0,
+    unit         => 'per hour',
+  },
+  VIF_PER_DAY => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100011,
+    bias         => 0,
+    unit         => 'per day',
+  },
+  VIF_PER_WEEK => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100100,
+    bias         => 0,
+    unit         => 'per week',
+  },
+  VIF_PER_MONTH => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100101,
+    bias         => 0,
+    unit         => 'per month',
+  },
+  VIF_PER_YEAR => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100110,
+    bias         => 0,
+    unit         => 'per year',
+  },
+  VIF_PER_REVOLUTION => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00100111,
+    bias         => 0,
+    unit         => 'per revolution/measurement',
+  },
+  VIF_PER_INCREMENT_INPUT => {
+    typeMask     => 0b01111110,
+    expMask      => 0b00000000,
+    type         => 0b00101000,
+    bias         => 0,
+    unit         => 'increment per input pulse on input channnel #',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_PER_INCREMENT_OUTPUT => {
+    typeMask     => 0b01111110,
+    expMask      => 0b00000000,
+    type         => 0b00101010,
+    bias         => 0,
+    unit         => 'increment per output pulse on output channnel #',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_PER_LITER => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00101100,
+    bias         => 0,
+    unit         => 'per liter',
+  },
+  VIF_PER_M3 => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00101101,
+    bias         => 0,
+    unit         => 'per m³',
+  },
+  VIF_PER_KG => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00101110,
+    bias         => 0,
+    unit         => 'per kg',
+  },  
+  VIF_PER_K => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00101111,
+    bias         => 0,
+    unit         => 'per K',
+  },  
+  VIF_PER_KWH => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00110000,
+    bias         => 0,
+    unit         => 'per kWh',
+  },  
+  VIF_PER_GJ => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00110001,
+    bias         => 0,
+    unit         => 'per GJ',
+  },  
+  VIF_PER_KW => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00110010,
+    bias         => 0,
+    unit         => 'per kW',
+  },  
+  VIF_PER_KL => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00110011,
+    bias         => 0,
+    unit         => 'per (K*l)',
+  },  
+  VIF_PER_V => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00110100,
+    bias         => 0,
+    unit         => 'per V',
+  },  
+  VIF_PER_A => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00110101,
+    bias         => 0,
+    unit         => 'per A',
+  },  
+  VIF_PER_MULT_S => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00110110,
+    bias         => 0,
+    unit         => 'multiplied by sek',
+  },  
+  VIF_PER_MULT_SV => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00110111,
+    bias         => 0,
+    unit         => 'multiplied by sek / V',
+  },  
+  VIF_PER_MULT_SA => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00111000,
+    bias         => 0,
+    unit         => 'multiplied by sek / A',
+  },  
+
+  VIF_START_DATE_TIME => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00111001,
+    bias         => 0,
+    unit         => 'start date(/time) of',
+  },
+  
+  VIF_ACCUMULATION_IF_POSITIVE => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b00111011,
+    bias         => 0,
+    unit         => 'Accumulation only if positive contribution',
+  },
+  
+  VIF_DURATION_NO_EXCEEDS => {
+    typeMask     => 0b01110111,
+    expMask      => 0b00000000,
+    type         => 0b01000001,
+    bias         => 0,
+    unit         => '# of exceeds',
+    calcFunc     => \&valueCalcu,
+  },
+
+  VIF_DURATION_LIMIT_EXCEEDED => {
+    typeMask     => 0b01110000,
+    expMask      => 0b00000000,
+    type         => 0b01010000,
+    bias         => 0,
+    unit         => 'duration of limit exceeded',
+    calcFunc     => \&valueCalcufnn,
+  },
+
+  VIF_MULTIPLICATIVE_CORRECTION_FACTOR => {
+    typeMask     => 0b01111000,
+    expMask      => 0b00000111,
+    type         => 0b01110000,
+    bias         => -6,
+    unit         => '',
+  },  
+  VIF_MULTIPLICATIVE_CORRECTION_FACTOR_1000 => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01111101,
+    bias         => 0,
+    unit         => '',
+    calcFunc     => \&valueCalcMultCorr1000,
+  },  
+  VIF_FUTURE_VALUE => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01111110,
+    bias         => 0,
+    unit         => '',
+  },  
+  VIF_MANUFACTURER_SPECIFIC => {
+    typeMask     => 0b01111111,
+    expMask      => 0b00000000,
+    type         => 0b01111111,
+    bias         => 0,
+    unit         => 'manufacturer specific',
+  },  
+  
+);
+
+# For Easymeter (manufacturer specific)
+my %VIFInfo_ESY = (       
+  VIF_ELECTRIC_POWER_PHASE => {
+    typeMask     => 0b01000000,
+    expMask      => 0b00000000,
+    type         => 0b00000000,
+    bias         => -2,
+    unit         => 'W',
+    calcFunc     => \&valueCalcNumeric,
+  },
+  VIF_ELECTRIC_POWER_PHASE_NO => {
+    typeMask     => 0b01111110,
+    expMask      => 0b00000000,
+    type         => 0b00101000,
+    bias         => 0,
+    unit         => 'phase #',
+    calcFunc     => \&valueCalcNumeric,
+  },
+);
+
+# For Kamstrup (manufacturer specific)
+my %VIFInfo_KAM = (       
+  VIF_KAMSTRUP_INFO => {
+    typeMask     => 0b00000000,
+    expMask      => 0b00000000,
+    type         => 0b00000000,
+    bias         => 0,
+    unit         => '',
+  },
+);
+
+
+# see 4.2.3, page 24
+my %validDeviceTypes = (
+ 0x00 => 'Other',
+ 0x01 => 'Oil',
+ 0x02 => 'Electricity',
+ 0x03 => 'Gas',
+ 0x04 => 'Heat',
+ 0x05 => 'Steam',
+ 0x06 => 'Warm Water (30 °C ... 90 °C)',
+ 0x07 => 'Water',
+ 0x08 => 'Heat Cost Allocator',
+ 0x09 => 'Compressed Air',
+ 0x0a => 'Cooling load meter (Volume measured at return temperature: outlet)',
+ 0x0b => 'Cooling load meter (Volume measured at flow temperature: inlet)',
+ 0x0c => 'Heat (Volume measured at flow temperature: inlet)',
+ 0x0d => 'Heat / Cooling load meter',
+ 0x0e => 'Bus / System component',
+ 0x0f => 'Unknown Medium',
+ 0x10 => 'Reserved for utility meter',
+ 0x11 => 'Reserved for utility meter',
+ 0x12 => 'Reserved for utility meter',
+ 0x13 => 'Reserved for utility meter',
+ 0x14 => 'Calorific value',
+ 0x15 => 'Hot water (> 90 °C)',
+ 0x16 => 'Cold water',
+ 0x17 => 'Dual register (hot/cold) Water meter',
+ 0x18 => 'Pressure',
+ 0x19 => 'A/D Converter',
+ 0x1a => 'Smokedetector',
+ 0x1b => 'Room sensor (e.g. temperature or humidity)',
+ 0x1c => 'Gasdetector',
+ 0x1d => 'Reserved for sensors',
+ 0x1e => 'Reserved for sensors',
+ 0x1f => 'Reserved for sensors',
+ 0x20 => 'Breaker (electricity)',
+ 0x21 => 'Valve (gas)',
+ 0x22 => 'Reserved for switching devices',
+ 0x23 => 'Reserved for switching devices',
+ 0x24 => 'Reserved for switching devices',
+ 0x25 => 'Customer unit (Display device)',
+ 0x26 => 'Reserved for customer units',
+ 0x27 => 'Reserved for customer units',
+ 0x28 => 'Waste water',
+ 0x29 => 'Garbage',
+ 0x2a => 'Carbon dioxide',
+ 0x2b => 'Environmental meter',
+ 0x2c => 'Environmental meter',
+ 0x2d => 'Environmental meter',
+ 0x2e => 'Environmental meter',
+ 0x2f => 'Environmental meter',
+ 0x31 => 'OMS MUC',
+ 0x32 => 'OMS unidirectional repeater',
+ 0x33 => 'OMS bidirectional repeater',
+ 0x37 => 'Radio converter (Meter side)',
+);
+
+
+# bitfield, errors can be combined, see 4.2.3.2 on page 22
+my %validStates = (
+  0x00 => 'no errors',
+  0x01 => 'application busy',
+  0x02 => 'any application error',
+  0x03 => 'abnormal condition/alarm',
+  0x04 => 'battery low',
+  0x08 => 'permanent error',
+  0x10 => 'temporary error',
+  0x20 => 'specific to manufacturer',
+  0x40 => 'specific to manufacturer',
+  0x80 => 'specific to manufacturer',
+  
+);
+
+my %encryptionModes = (
+  0x00 => 'standard unsigned',
+  0x01 => 'signed data telegram',
+  0x02 => 'static telegram',
+  0x03 => 'reserved',
+);
+
+my %functionFieldTypes = (
+  0b00 => 'Instantaneous value',
+  0b01 => 'Maximum value',
+  0b10 => 'Minimum value',
+  0b11 => 'Value during error state',
+);
+
+
+sub type2string($$) {
+  my $class = shift;
+  my $type = shift;
+  
+  return $validDeviceTypes{$type} || 'unknown';
+}
+
+sub state2string($$) {
+  my $class = shift;
+  my $state = shift;
+  
+  my @result = ();
+  
+  if ($state) {
+    foreach my $stateMask ( keys %validStates ) {
+      push @result, $validStates{$stateMask} if $state & $stateMask;
+    }
+  } else {
+    @result = ($validStates{0});
+  }
+  return @result;
+}
+
+
+sub calcCRC($$) {
+  my $self = shift;
+  my $data = shift;
+  my $ctx = Digest::CRC->new(width=>16, init=>0x0000, xorout=>0xffff, refout=>0, poly=>0x3D65, refin=>0, cont=>0);
+
+  $ctx->add($data);
+
+  return $ctx->digest;  
+}
+
+
+sub removeCRC($$)
+{
+  my $self = shift;
+  my $msg = shift;
+  my $i;
+  my $res;
+  my $crc;
+  my $blocksize = LL_BLOCK_SIZE;
+  my $blocksize_with_crc = LL_BLOCK_SIZE + $self->{crc_size};
+  my $crcoffset;
+  
+  my $msgLen = $self->{datalen}; # size without CRCs
+  my $noOfBlocks = $self->{datablocks}; # total number of data blocks, each with a CRC appended
+  my $rest = $msgLen % LL_BLOCK_SIZE; # size of the last data block, can be smaller than 16 bytes
+  
+  
+  #print "crc_size $self->{crc_size}\n";
+  
+  return $msg if $self->{crc_size} == 0;
+
+  # each block is 16 bytes + 2 bytes CRC
+  
+  #print "Länge $msgLen Anz. Blöcke $noOfBlocks rest $rest\n";
+  
+  for ($i=0; $i < $noOfBlocks; $i++) {
+    $crcoffset = $blocksize_with_crc * $i + LL_BLOCK_SIZE;
+    #print "$i: crc offset $crcoffset\n";
+    if ($rest > 0 && $crcoffset + $self->{crc_size} > ($noOfBlocks - 1) * $blocksize_with_crc + $rest) {
+      # last block is smaller
+      $crcoffset = ($noOfBlocks - 1) * $blocksize_with_crc + $rest;
+      #print "last crc offset $crcoffset\n";
+      $blocksize = $msgLen - ($i * $blocksize); 
+    }
+    
+    $crc = unpack('n',substr($msg, $crcoffset, $self->{crc_size}));
+    #printf("%d: CRC %x, calc %x blocksize $blocksize\n", $i, $crc, $self->calcCRC(substr($msg, $blocksize_with_crc*$i, $blocksize))); 
+    if ($crc != $self->calcCRC(substr($msg, $blocksize_with_crc*$i, $blocksize))) {
+      $self->{errormsg} = "crc check failed for block $i";
+      $self->{errorcode} = ERR_CRC_FAILED;
+      return 0;
+    }
+    $res .= substr($msg, $blocksize_with_crc*$i, $blocksize);
+  }
+
+  return $res;
+}
+
+
+sub manId2hex($$)
+{
+  my $class = shift;
+  my $idascii = shift;
+  
+  return (ord(substr($idascii,1,1))-64) << 10 | (ord(substr($idascii,2,1))-64) << 5 | (ord(substr($idascii,3,1))-64);
+}
+
+sub manId2ascii($$)
+{
+  my $class = shift;
+  my $idhex = shift;
+    
+  return chr(($idhex >> 10) + 64) . chr((($idhex >> 5) & 0b00011111) + 64) . chr(($idhex & 0b00011111) + 64);
+}
+
+
+sub new {
+  my $class = shift;
+  my $self = {};
+  bless $self, $class;
+  
+  $self->_initialize();
+  return $self;
+}
+
+sub _initialize {
+  my $self = shift;
+  
+  $self->{crc_size} = CRC_SIZE;
+  $self->{frame_type} = FRAME_TYPE_A; # default
+}
+
+sub setCRCsize {
+  my $self = shift;
+
+  $self->{crc_size} = shift;
+}
+
+sub getCRCsize {
+  my $self = shift;
+
+  return $self->{crc_size};
+}
+
+sub decodeConfigword($) {
+  my $self = shift;
+
+  
+  #printf("cw: %01x %01x\n", $self->{cw_1}, $self->{cw_2});
+  $self->{cw_parts}{mode}             = ($self->{cw_2} & 0b00011111);
+  #printf("mode: %02x\n", $self->{cw_parts}{mode});
+  if ($self->{cw_parts}{mode} == 5 || $self->{cw_parts}{mode} == 0) {
+    $self->{cw_parts}{bidirectional}    = ($self->{cw_2} & 0b10000000) >> 7;
+    $self->{cw_parts}{accessability}    = ($self->{cw_2} & 0b01000000) >> 6;
+    $self->{cw_parts}{synchronous}      = ($self->{cw_2} & 0b00100000) >> 5;
+    $self->{cw_parts}{encrypted_blocks} = ($self->{cw_1} & 0b11110000) >> 4;
+    $self->{cw_parts}{content}          = ($self->{cw_1} & 0b00001100) >> 2;
+    $self->{cw_parts}{repeated_access}  = ($self->{cw_1} & 0b00000010) >> 1;
+    $self->{cw_parts}{hops}             = ($self->{cw_1} & 0b00000001);
+  } elsif ($self->{cw_parts}{mode} == 7) {
+    # configword ist 3 Bytes lang
+    $self->{cw_parts}{key_id}           = ($self->{cw_3} & 0b00001111);
+    $self->{cw_parts}{dynamic_key}      = ($self->{cw_3} & 0b01110000) >> 4;
+    $self->{cw_parts}{content}          = ($self->{cw_2} & 0b11000000) >> 6;
+    $self->{cw_parts}{encrypted_blocks} = ($self->{cw_1} & 0b11110000) >> 4;
+  }
+}
+
+sub decodeBCD($$$) {
+  my $self = shift;
+  my $digits = shift;
+  my $bcd = shift;
+  my $byte;
+  my $val=0;
+  my $mult=1;
+  
+  #print "bcd:" . unpack("H*", $bcd) . "\n";
+  
+  for (my $i = 0; $i < $digits/2; $i++) {
+    $byte = unpack('C',substr($bcd, $i, 1));
+    $val += ($byte & 0x0f) * $mult;
+    $mult *= 10;
+    $val += (($byte & 0xf0) >> 4) * $mult;
+    $mult *= 10;
+  }
+  return $val;
+}
+
+sub findVIF($$$) {
+  my $vif = shift;
+  my $vifInfoRef = shift;
+  my $dataBlockRef = shift;
+  my $bias;
+  
+  if (defined $vifInfoRef) {
+    VIFID: foreach my $vifType ( keys %$vifInfoRef ) { 
+    
+      #printf "vifType $vifType VIF $vif typeMask $vifInfoRef->{$vifType}{typeMask} type $vifInfoRef->{$vifType}{type}\n"; 
+    
+      if (($vif & $vifInfoRef->{$vifType}{typeMask}) == $vifInfoRef->{$vifType}{type}) {
+        #printf " match vifType $vifType\n"; 
+        
+        $bias = $vifInfoRef->{$vifType}{bias};
+        $dataBlockRef->{exponent} = $vif & $vifInfoRef->{$vifType}{expMask};
+        
+        $dataBlockRef->{type} = $vifType;
+        $dataBlockRef->{unit} = $vifInfoRef->{$vifType}{unit};
+        if (defined $dataBlockRef->{exponent} && defined $bias) {
+          $dataBlockRef->{valueFactor} = 10 ** ($dataBlockRef->{exponent} + $bias);
+        } else {
+          $dataBlockRef->{valueFactor} = 1;
+        }
+        $dataBlockRef->{calcFunc} = $vifInfoRef->{$vifType}{calcFunc};
+        
+        #printf("type %s bias %d exp %d valueFactor %d unit %s\n", $dataBlockRef->{type}, $bias, $dataBlockRef->{exponent}, $dataBlockRef->{valueFactor},$dataBlockRef->{unit});
+        return 1;
+      }
+    }
+    #printf "no match!\n";
+    return 0;
+  }
+  return 1;
+}
+
+sub decodePlaintext($$$) {
+  my $self = shift;
+  my $vib = shift;
+  my $dataBlockRef = shift;
+  my $offset = shift;
+  my $vifLength = unpack('C', substr($vib,$offset++,1));
+  
+  $dataBlockRef->{type} = "see unit";
+  $dataBlockRef->{unit} = substr($vib, $offset, $vifLength);
+  $dataBlockRef->{unit} = reverse($dataBlockRef->{unit}) unless $self->{mode_bit}; 
+  $offset += $vifLength;
+  return $offset;
+}
+
+sub decodeValueInformationBlock($$$) {
+  my $self = shift;
+  my $vib = shift;
+  my $dataBlockRef = shift;
+  
+  my $offset = 0;
+  my $vif;
+  my $vifInfoRef;
+  my $vifExtension = 0;
+  my $vifExtNo = 0;
+  my $isExtension;
+  my $dataBlockExt;
+  my @VIFExtensions = ();
+  my $analyzeVIF = 1;
+
+  $dataBlockRef->{type}  = '';
+  # The unit and multiplier is taken from the table for primary VIF
+  $vifInfoRef = \%VIFInfo;
+  
+
+  EXTENSION: while (1) {
+    $vif = unpack('C', substr($vib,$offset++,1));
+    $isExtension = $vif & VIF_EXTENSION_BIT;
+    #printf("vif: %x isExtension %d\n", $vif, $isExtension);
+    
+    # Is this an extension?
+    last EXTENSION if (!$isExtension);
+    
+    # yes, process extension
+
+    $vifExtNo++;
+    if ($vifExtNo > 10) {
+      $dataBlockRef->{errormsg} = 'too many VIFE';
+      $dataBlockRef->{errorcode} = ERR_TOO_MANY_VIFE;
+      last EXTENSION;
+    }
+    
+    # switch to extension codes
+    $vifExtension = $vif;
+    $vif &= ~VIF_EXTENSION_BIT;
+    #printf("vif ohne extension: %x\n", $vif);
+    if ($vif == 0x7D) {
+      $vifInfoRef = \%VIFInfo_FD;
+    } elsif ($vif == 0x7B) {
+      $vifInfoRef = \%VIFInfo_FB;
+    } elsif ($vif == 0x7C) {
+      # Plaintext VIF
+      $offset = $self->decodePlaintext($vib, $dataBlockRef, $offset);
+      $analyzeVIF = 0;
+      last EXTENSION;
+    } elsif ($vif == 0x7F) {
+      
+      if ($self->{manufacturer} eq 'ESY') {
+        # Easymeter
+        $vif = unpack('C', substr($vib,$offset++,1));
+        $vifInfoRef = \%VIFInfo_ESY;
+      } elsif ($self->{manufacturer} eq 'KAM') {
+        $vif = unpack('C', substr($vib,$offset++,1));
+        $vifInfoRef = \%VIFInfo_KAM;       
+      } else {
+        # manufacturer specific data, can't be interpreted
+        
+        $dataBlockRef->{type} = VIF_TYPE_MANUFACTURER_SPECIFIC;
+        $dataBlockRef->{unit} = "";
+        $analyzeVIF = 0;
+      }
+      last EXTENSION;
+    } else {
+      # enhancement of VIFs other than $FD and $FB (see page 84ff.)
+      #print "other extension\n";
+      $dataBlockExt = {};
+      if ($self->{manufacturer} eq 'ESY') {
+        $vifInfoRef = \%VIFInfo_ESY;
+        $dataBlockExt->{value} = unpack('C',substr($vib,2,1)) * 100;
+      } else {
+        $dataBlockExt->{value} = $vif;
+        $vifInfoRef = \%VIFInfo_other;
+      }
+      
+      if (findVIF($vif, $vifInfoRef, $dataBlockExt)) {
+        push @VIFExtensions, $dataBlockExt;
+      } else {
+        $dataBlockRef->{type} = 'unknown';
+        $dataBlockRef->{errormsg} = "unknown VIFE " . sprintf("%x", $vifExtension) . " at offset " . ($offset-1);
+        $dataBlockRef->{errorcode} = ERR_UNKNOWN_VIFE;    
+      }    
+    }
+    last EXTENSION if (!$isExtension);
+  }
+
+  if ($analyzeVIF) {  
+    if ($vif == 0x7C) {
+      # Plaintext VIF
+      $offset = $self->decodePlaintext($vib, $dataBlockRef, $offset);
+    } elsif (findVIF($vif, $vifInfoRef, $dataBlockRef) == 0) {
+      $dataBlockRef->{errormsg} = "unknown VIF " . sprintf("%x", $vifExtension) . " at offset " . ($offset-1);
+      $dataBlockRef->{errorcode} = ERR_UNKNOWN_VIFE;    
+    }
+  }
+  $dataBlockRef->{VIFExtensions} = \@VIFExtensions;
+
+  if ($dataBlockRef->{type} eq '') {
+    $dataBlockRef->{type} = 'unknown';
+    $dataBlockRef->{errormsg} = sprintf("in VIFExtension %x unknown VIF %x",$vifExtension, $vif);
+    $dataBlockRef->{errorcode} = ERR_UNKNOWN_VIF;
+  }
+  
+  return $offset;
+  
+  
+}
+
+
+sub decodeDataInformationBlock($$$) {
+  my $self = shift;
+  my $dib = shift;
+  my $dataBlockRef = shift;
+  
+  my $dif;
+  my $tariff = 0;
+  my $difExtNo = 0;
+  my $offset;
+  my $devUnit = 0;
+  
+  $dif = unpack('C', $dib);
+  $offset = 1;
+  my $isExtension = $dif & DIF_EXTENSION_BIT;
+  my $storageNo = ($dif & 0b01000000) >> 6;
+  my $functionField = ($dif & 0b00110000) >> 4;
+  my $df = $dif & 0b00001111;
+
+  #printf("dif %x storage %d\n", $dif, $storageNo);
+  
+  EXTENSION: while ($isExtension) {
+    $dif = unpack('C', substr($dib,$offset,1));
+    last EXTENSION if (!defined $dif);
+    $offset++;
+    $isExtension = $dif & DIF_EXTENSION_BIT;
+    $difExtNo++;
+    if ($difExtNo > 10) {
+      $dataBlockRef->{errormsg} = 'too many DIFE';
+      $dataBlockRef->{errorcode} = ERR_TOO_MANY_DIFE;
+      last EXTENSION;
+    }
+    
+    $storageNo |= ($dif & 0b00001111) << ($difExtNo*4)+1;
+    $tariff    |= (($dif & 0b00110000) >> 4) << (($difExtNo-1)*2);
+    $devUnit   |= (($dif & 0b01000000) >> 6) << ($difExtNo-1);
+    #printf("dife %x extno %d storage %d\n", $dif, $difExtNo, $storageNo);
+  }
+  
+  $dataBlockRef->{functionField} = $functionField;
+  $dataBlockRef->{functionFieldText} = $functionFieldTypes{$functionField};
+  $dataBlockRef->{dataField} = $df;
+  $dataBlockRef->{storageNo} = $storageNo;
+  $dataBlockRef->{tariff} = $tariff;
+  $dataBlockRef->{devUnit} = $devUnit;
+  
+  #printf("in DIF: datafield %x\n", $dataBlockRef->{dataField});
+  #print "offset in dif $offset\n";
+  return $offset;
+}
+
+sub decodeDataRecordHeader($$$) {
+  my $self = shift;
+  my $drh = shift;
+  my $dataBlockRef = shift;
+  
+  my $offset = $self->decodeDataInformationBlock($drh,$dataBlockRef);
+
+  
+  $offset += $self->decodeValueInformationBlock(substr($drh,$offset),$dataBlockRef);
+  #printf("in DRH: type %s\n", $dataBlockRef->{type});
+  
+  return $offset;
+}
+
+
+
+sub decodePayload($$) {
+  my $self = shift;
+  my $payload = shift;
+  my $offset = 0;
+  my $dif;
+  my $vif;
+  my $scale;
+  my $value;
+  my $dataBlockNo = 0;
+  
+  
+  my @dataBlocks = ();
+  my $dataBlock;
+
+  
+  PAYLOAD: while ($offset < length($payload)) {
+    $dataBlockNo++;
+    
+    # create a new anonymous hash reference
+    $dataBlock = {};
+    $dataBlock->{number} = $dataBlockNo;
+    $dataBlock->{unit} = '';
+    
+    while (unpack('C',substr($payload,$offset,1)) == 0x2f) {
+      # skip filler bytes
+      #printf("skipping filler at offset %d of %d\n", $offset, length($payload));
+      $offset++;
+      if ($offset >= length($payload)) {
+        last PAYLOAD;
+      }
+    }
+    
+    $offset += $self->decodeDataRecordHeader(substr($payload,$offset), $dataBlock);
+    #printf("No. %d, type %x at offset %d\n", $dataBlockNo, $dataBlock->{dataField}, $offset-1);
+    
+    if ($dataBlock->{dataField} == DIF_NONE or $dataBlock->{dataField} == DIF_READOUT) {
+      $dataBlockNo--;
+      $offset++;
+    } elsif ($dataBlock->{dataField} == DIF_BCD2) {
+      $value = $self->decodeBCD(2, substr($payload,$offset,1));
+      $offset += 1;
+    } elsif ($dataBlock->{dataField} == DIF_BCD4) {
+      $value = $self->decodeBCD(4, substr($payload,$offset,2));
+      $offset += 2;
+    } elsif ($dataBlock->{dataField} == DIF_BCD6) {
+      $value = $self->decodeBCD(6, substr($payload,$offset,3));
+      $offset += 3;
+    } elsif ($dataBlock->{dataField} == DIF_BCD8) {
+      $value = $self->decodeBCD(8, substr($payload,$offset,4));
+      $offset += 4;
+    } elsif ($dataBlock->{dataField} == DIF_BCD12) {
+      $value = $self->decodeBCD(12, substr($payload,$offset,6));
+      $offset += 6;
+    } elsif ($dataBlock->{dataField} == DIF_INT8) {
+      $value = unpack('C', substr($payload, $offset, 1));
+      $offset += 1;
+    } elsif ($dataBlock->{dataField} == DIF_INT16) {
+      $value = unpack('v', substr($payload, $offset, 2));
+      $offset += 2;
+    } elsif ($dataBlock->{dataField} == DIF_INT24) {
+      my @bytes = unpack('CCC', substr($payload, $offset, 3));
+      $offset += 3;
+      $value = $bytes[0] + $bytes[1] << 8 + $bytes[2] << 16;
+    } elsif ($dataBlock->{dataField} == DIF_INT32) {
+      $value = unpack('V', substr($payload, $offset, 4));
+      $offset += 4;
+    } elsif ($dataBlock->{dataField} == DIF_INT48) {
+      my @words = unpack('vvv', substr($payload, $offset, 6));
+      $value = $words[0] + ($words[1] << 16) + ($words[2] << 32);
+      $offset += 6;
+    } elsif ($dataBlock->{dataField} == DIF_INT64) {
+      $value = unpack('Q<', substr($payload, $offset, 8));
+      $offset += 8;
+    } elsif ($dataBlock->{dataField} == DIF_FLOAT32) {
+      #not allowed according to wmbus standard, Qundis seems to use it nevertheless
+      $value = unpack('f', substr($payload, $offset, 4));
+      $offset += 4;
+    } elsif ($dataBlock->{dataField} == DIF_VARLEN) {
+      my $lvar = unpack('C',substr($payload, $offset++, 1));
+      #print "in datablock $dataBlockNo: LVAR field " . sprintf("%x", $lvar) . "\n";
+      #printf "payload len %d offset %d\n", length($payload), $offset;
+      if ($lvar <= 0xbf) {
+        if ($dataBlock->{type} eq "MANUFACTURER SPECIFIC") {
+          # special handling, LSE seems to lie about this
+          $value = unpack('H*',substr($payload, $offset, $lvar));
+          #print "VALUE: " . $value . "\n";
+        } else {
+          #  ASCII string with LVAR characters
+          $value = unpack('a*',substr($payload, $offset, $lvar));
+          
+          # check if value only contains printable chars 
+          if(($value =~ tr/\x20-\x7d//c) == 0) {
+          
+            if ($self->{manufacturer} eq 'ESY') {
+              # Easymeter stores the string backwards!
+              $value = reverse($value);
+            }
+          } else {
+            $self->{errormsg} = "Non printable ASCII in LVAR";
+            $self->{errorcode} = ERR_UNKNOWN_DATAFIELD;
+            return 0;
+          }
+        }
+        $offset += $lvar;
+      } elsif ($lvar >= 0xc0 && $lvar <= 0xcf) {
+        #  positive BCD number with (LVAR - C0h) • 2 digits
+        $value = $self->decodeBCD(($lvar-0xc0)*2, substr($payload,$offset,($lvar-0xc0)));
+        $offset += ($lvar-0xc0);
+      } elsif ($lvar >= 0xd0 && $lvar <= 0xdf) {
+        #  negative BCD number with (LVAR - D0h) • 2 digits
+        $value = -$self->decodeBCD(($lvar-0xd0)*2, substr($payload,$offset,($lvar-0xd0)));
+        $offset += ($lvar-0xd0);
+      } else {
+        $self->{errormsg} = "in datablock $dataBlockNo: unhandled LVAR field " . sprintf("%x", $lvar);
+        $self->{errorcode} = ERR_UNKNOWN_LVAR;
+        return 0;
+      }
+    } elsif ($dataBlock->{dataField} == DIF_SPECIAL) {
+      # special functions
+      #print "DIF_SPECIAL at $offset\n";
+      $value = unpack("H*", substr($payload,$offset));
+      last PAYLOAD;
+    } else {
+      $self->{errormsg} = "in datablock $dataBlockNo: unhandled datafield " . sprintf("%x",$dataBlock->{dataField});
+      $self->{errorcode} = ERR_UNKNOWN_DATAFIELD;
+      return 0;
+    }
+    
+    if (defined $dataBlock->{calcFunc}) {
+      $dataBlock->{value} = $dataBlock->{calcFunc}->($value, $dataBlock); 
+      #print "Value raw " . $value . " value calc " . $dataBlock->{value} ."\n";
+    } elsif (defined $value) {
+      $dataBlock->{value} = $value;
+    } else {
+      $dataBlock->{value} = "";
+    }
+    
+    my $VIFExtensions = $dataBlock->{VIFExtensions};
+    for my $VIFExtension (@$VIFExtensions) {
+      $dataBlock->{extension} = $VIFExtension->{unit};
+      if (defined $VIFExtension->{calcFunc}) {
+        #printf("Extension value %d, valueFactor %d\n", $VIFExtension->{value}, $VIFExtension->{valueFactor});
+        $dataBlock->{extension} .= ", " . $VIFExtension->{calcFunc}->($VIFExtension->{value}, $dataBlock); 
+      } elsif (defined $VIFExtension->{value}) {
+        $dataBlock->{extension} .= ", " . sprintf("%x",$VIFExtension->{value});
+      } else {
+        #$dataBlock->{extension} = "";
+      }
+    }
+    undef $value;
+    
+    push @dataBlocks, $dataBlock;
+  }
+  
+  $self->{datablocks} = \@dataBlocks;
+  return 1;
+}
+
+sub decrypt_mode5($) {
+  my $self = shift;
+  my $encrypted = shift;
+  my $padding = 2;
+  
+  # see 4.2.5.3, page 26      
+  my $initVector = substr($self->{msg},2,8);
+  for (1..8) {
+    $initVector .= pack('C',$self->{access_no});
+  }
+  
+  if (length($encrypted)%16 == 0) {
+    # no padding if data length is multiple of blocksize
+    $padding = 0;
+  } else {
+    $padding = 2;
+  }
+  #printf("length encrypted %d padding %d\n", length($encrypted), $padding);
+  my $cipher = Crypt::Mode::CBC->new('AES', $padding);
+  return $cipher->decrypt($encrypted, $self->{aeskey}, $initVector);
+}
+
+sub decrypt_mode7($) {
+  my $self = shift;
+  my $encrypted = shift;
+  my $padding = 2;
+  
+  # generate dynamic key
+  my $cmac = Digest::CMAC->new($self->{aeskey});
+  #my $cmac = Digest::CMAC->new(pack("H*",'000102030405060708090A0B0C0D0E0F'));
+  
+  # The calculation of Kenc and Kmac for the meter:
+  # Kenc = CMAC(MK, 0x00 ||C[7..0] ||C[15..8] ||C[23..16] ||C[31..24] ||ID_0||ID_1||ID_2||ID_3||0x07||0x07||0x07||0x07||0x07||0x07||0x07)
+  # Where C[7..0] is the LSB and C[31..24] is the MSB (Big Endian) of the counter AFL.MCR.C from meter to other (gateway).
+  
+  $cmac->add(pack("H*", "00"));
+  
+  #$self->{afl}{mcr} = pack("H*", "b30a0000");
+  $cmac->add($self->{afl}{mcr});
+  #print "MCR " . unpack("H*", $self->{afl}{mcr}) . "\n";
+  #print "identno " . unpack("H*", $self->{afield_identno}) . "\n";
+  $cmac->add($self->{afield_identno});
+  $cmac->add(pack("H*", "07070707070707"));
+  #$cmac->add(pack("H*",'7856341207070707070707'));
+  
+  
+  
+  my $key = $cmac->digest;
+  
+  #printf("Dynamic key %s\n", $cmac->hexdigest);
+  
+  # see 9.2.3, page 52      
+  my $initVector = '';
+  for (1..16) {
+    $initVector .= pack('C',0x00);
+  }
+  if (length($encrypted)%16 == 0) {
+    # no padding if data length is multiple of blocksize
+    $padding = 0;
+  } else {
+    $padding = 2;
+  }  
+  
+  #$encrypted = pack("H*","9058475F4BC91DF878B80A1B0F98B629024AAC727942BFC549233C0140829B93");
+  #print unpack("H*", $encrypted) . "\n";
+  my $cipher = Crypt::Mode::CBC->new('AES', $padding);
+  return $cipher->decrypt($encrypted, $key, $initVector);
+}
+
+sub decodeAFL($$) {
+  my $self = shift;
+  my $afl = shift;
+  my $offset = 0;
+  
+  
+  $self->{afl}{fcl} = unpack('v', $afl);
+  $offset += 2;
+  $self->{afl}{fcl_mf}   = ($self->{afl}{fcl} & 0b0100000000000000) != 0;
+  $self->{afl}{fcl_mclp} = ($self->{afl}{fcl} & 0b0010000000000000) != 0;
+  $self->{afl}{fcl_mlp}  = ($self->{afl}{fcl} & 0b0001000000000000) != 0;
+  $self->{afl}{fcl_mcrp} = ($self->{afl}{fcl} & 0b0000100000000000) != 0;
+  $self->{afl}{fcl_macp} = ($self->{afl}{fcl} & 0b0000010000000000) != 0;
+  $self->{afl}{fcl_kip}  = ($self->{afl}{fcl} & 0b0000001000000000) != 0;
+  $self->{afl}{fcl_fid}  =  $self->{afl}{fcl} & 0b0000000011111111;
+  
+  if ($self->{afl}{fcl_mclp}) {
+    # AFL Message Control Field (AFL.MCL)
+    $self->{afl}{mcl} = unpack('C', substr($afl, $offset, 1));
+    #printf "AFL MCL %01x\n", $self->{afl}{mcl};
+    $offset += 1;
+    $self->{afl}{mcl_mlmp} = ($self->{afl}{mcl} & 0b01000000) != 0; 
+    $self->{afl}{mcl_mcmp} = ($self->{afl}{mcl} & 0b00100000) != 0; 
+    $self->{afl}{mcl_kimp} = ($self->{afl}{mcl} & 0b00010000) != 0; 
+    $self->{afl}{mcl_at}   = ($self->{afl}{mcl} & 0b00001100) >> 2; 
+    $self->{afl}{mcl_ato}  = ($self->{afl}{mcl} & 0b00000011); 
+  }
+  if ($self->{afl}{fcl_mcrp}) {
+    # AFL Message Counter Field (AFL.MCR)
+    #$self->{afl}{mcr} = unpack('N', substr($afl, $offset));
+    $self->{afl}{mcr} = substr($afl, $offset, 4);
+    $offset += 4;
+  }
+  if ($self->{afl}{fcl_mlp}) {
+    # AFL Message Length Field (AFL.ML)
+    $self->{afl}{ml} = unpack('v', substr($afl, $offset));
+    $offset += 2;
+  }
+  if ($self->{afl}{mcl_at} == 1) {
+    # CMAC-AES128 (see 9.3.1)
+    my $mac_len = 0;
+    if ($self->{afl}{mcl_ato} == 1) {
+      $mac_len = 8;
+      $self->{afl}{mac} = (unpack('N', substr($afl, $offset, 4))) << 32 | ((unpack('N', substr($afl, $offset+4, 4))));
+      #printf "AFL MAC %8x\n", $self->{afl}{mac};
+    } else {
+      # reserved
+    }
+    $offset += $mac_len;
+  }
+  if ($self->{afl}{fcl_kip}) {
+    # AFL Key Information-Field (AFL.KI)
+    $self->{afl}{ki} = unpack('v', $afl);
+    $self->{afl}{ki_key_version}   = ($self->{afl}{ki} & 0b1111111100000000) >> 8;
+    $self->{afl}{ki_kdf_selection} = ($self->{afl}{ki} & 0b0000000001110000) >> 4;
+    $self->{afl}{ki_key_id}        = ($self->{afl}{ki} & 0b0000000000001111);
+    $offset += 2;
+  }
+  return $offset;
+}
+
+sub decodeApplicationLayer($) {
+  my $self = shift;
+  my $applicationlayer = $self->{applicationlayer};
+  my $payload;
+  
+  #print unpack("H*", $applicationlayer) . "\n";
+  
+  if ($self->{errorcode} != ERR_NO_ERROR) {
+    # CRC check failed
+    return 0;
+  }
+  $self->{cifield} = unpack('C', $applicationlayer);
+
+  my $offset = 1;
+  my $has_ell = 1;
+
+  if ($self->{cifield} == CI_ELL_2) {
+    # Extended Link Layer
+    ($self->{ell}{cc}, $self->{ell}{access_no}) = unpack('CC', substr($applicationlayer,$offset));
+    $offset += 2;
+  } elsif ($self->{cifield} == CI_ELL_6) {
+    # Extended Link Layer
+    ($self->{ell}{cc}, $self->{ell}{access_no}) = unpack('CC', substr($applicationlayer,$offset));
+    $offset += 6;
+  } elsif ($self->{cifield} == CI_ELL_8) {
+    # Extended Link Layer, payload CRC is part of (encrypted) payload
+    ($self->{ell}{cc}, $self->{ell}{access_no}, $self->{ell}{session_number}) = unpack('CCV', substr($applicationlayer, $offset));
+    $offset += 6;
+  } elsif ($self->{cifield} == CI_ELL_16) {
+    # Extended Link Layer
+    ($self->{ell}{cc}, $self->{ell}{access_no}, $self->{ell}{m2}, $self->{ell}{a2}, $self->{ell}{session_number}) = unpack('CCvC6V', substr($applicationlayer,$offset));
+    $offset += 14;
+  } else {
+    $has_ell = 0;
+  }
+  
+  if (exists($self->{ell}{session_number})) {
+    $self->{ell}{session_number_enc} = $self->{ell}{session_number} >> 29;
+    $self->{ell}{session_number_time} = ($self->{ell}{session_number} & 0b0001111111111111111111111111111) >> 4;
+    $self->{ell}{session_number_session} = $self->{ell}{session_number} & 0b1111;
+    $self->{isEncrypted} = $self->{ell}{session_number_enc} != 0;
+    $self->{decrypted} = 0;
+    
+    if ($self->{isEncrypted}) {
+      if ($self->{aeskey}) {
+        if ($hasCTR) {
+          # AES IV
+          # M-field, A-field, CC, SN, 00, 0000
+          my $initVector = pack("v", $self->{mfield}) . $self->{afield} . pack("CV", $self->{ell}{cc}, $self->{ell}{session_number}) . pack("H*", "000000");
+          my $m = Crypt::Mode::CTR->new('AES', 1);
+          my $ciphertext = substr($applicationlayer,$offset); # payload CRC must also be decrypted
+          #printf("##ciphertext: %s\n", unpack("H*", $ciphertext));
+          $payload = $m->decrypt($ciphertext, $self->{aeskey}, $initVector);
+        
+          #printf("##plaintext   %s\n", unpack("H*", $payload));
+        } else {
+          $self->{errormsg} = 'Crypt::Mode::CTR is not installed, please install it (sudo cpan -i Crypt::Mode::CTR)';
+          $self->{errorcode} = ERR_CIPHER_NOT_INSTALLED;
+          return 0;
+        }
+      } else {
+        $self->{errormsg} = 'encrypted message and no aeskey provided';
+        $self->{errorcode} = ERR_NO_AESKEY;
+        return 0;
+      }
+    }   
+    $self->{ell}{crc} = unpack('v', $payload);
+    $offset += 2;
+    # PayloadCRC is  a  cyclic  redundancy  check  covering  the  remainder  of  the  frame  (excluding the CRC fields)
+    # payload CRC is also encrypted
+    if ($self->{ell}{crc} != $self->calcCRC(substr($payload, 2, $self->{lfield}-20))) {
+      #printf("crc %x, calculated %x\n", $self->{ell}{crc}, $self->calcCRC(substr($payload, 2, $self->{lfield}-20))); 
+      $self->{errormsg} = "Payload CRC check failed on ELL" . ($self->{isEncrypted} ? ", wrong AES key?" : "");
+      $self->{errorcode} = ERR_CRC_FAILED;
+      return 0;
+    } else {
+      $self->{decrypted} = 1;
+    }
+    $applicationlayer = $payload;
+    $offset = 2; # skip PayloadCRC
+  }
+  
+  if ($offset > 1) {
+    $applicationlayer = substr($applicationlayer,$offset);
+    $self->{cifield} = unpack('C', $applicationlayer);
+    $offset = 1;
+    if ($self->{cifield} == CI_AFL) {
+      # Authentification and Fragmentation Layer
+      $self->{afl}{afll} = unpack('C', substr($applicationlayer, $offset));
+      #printf "AFL AFLL %02x\n", $self->{afl}{afll};
+      $offset += 1;
+      $self->decodeAFL(substr($applicationlayer,$offset,$self->{afl}{afll}));
+      $offset += $self->{afl}{afll};
+      if ($self->{afl}{fcl_mf}) {
+        $self->{errormsg} = "fragmented messages are not yet supported";
+        $self->{errorcode} = ERR_FRAGMENT_UNSUPPORTED;
+        return 0;
+      }
+    }
+  }
+  
+  if ($offset > 1) {
+    $applicationlayer = substr($applicationlayer,$offset);
+    $self->{cifield} = unpack('C', $applicationlayer); 
+    $offset = 1;
+  }
+
+  # initialize some fields
+  $self->{cw_1} = 0;
+  $self->{cw_2} = 0;
+  $self->{cw_3} = 0;
+  $self->{status} = 0;
+  $self->{statusstring} = "";
+  $self->{access_no} = 0;
+  $self->{sent_from_master} = 0;
+  $self->{isEncrypted} = 0;
+  
+  #printf("CI Field %02x\n", $self->{cifield});
+  
+  # Config Word ist normalerweise 2 Bytes lang, nur bei encryption mode 7 drei Bytes
+  # erstmal drei Bytes auslesen, aber den Offset nur um 2 Bytes erhöhen
+  
+  if ($self->{cifield} == CI_RESP_4 || $self->{cifield} == CI_RESP_SML_4) {
+    # Short header
+    ($self->{access_no}, $self->{status}, $self->{cw_1}, $self->{cw_2}, $self->{cw_3}) = unpack('CCCCC', substr($applicationlayer,$offset));
+    #printf("Short header access_no %x\n", $self->{access_no});
+    $offset += 4;
+  } elsif ($self->{cifield} == CI_RESP_12 || $self->{cifield} == CI_RESP_SML_12) {
+    # Long header
+    ($self->{meter_id}, $self->{meter_man}, $self->{meter_vers}, $self->{meter_dev}, $self->{access_no}, $self->{status}, $self->{cw_1}, $self->{cw_2}, $self->{cw_3}) 
+      = unpack('VvCCCCCCC', substr($applicationlayer,$offset)); 
+    $self->{meter_id} = sprintf("%08d", $self->{meter_id});  
+    $self->{meter_devtypestring} =  $validDeviceTypes{$self->{meter_dev}} || 'unknown'; 
+    $self->{meter_manufacturer} = uc($self->manId2ascii($self->{meter_man}));
+    #printf("Long header access_no %x\n", $self->{access_no});
+    $offset += 12;
+  } elsif ($self->{cifield} == CI_RESP_0) {
+    # no header
+    #print "No header\n";
+
+  } elsif ($self->{cifield} == 0x79 && $self->{manufacturer} eq 'KAM') {
+    #print "Kamstrup compact frame header\n";
+    $self->{format_signature} = unpack("v", substr($applicationlayer,$offset, 2));
+    $offset += 2;
+    $self->{full_frame_payload_crc} = unpack("v", substr($applicationlayer, $offset, 2));
+    $offset += 2;
+    if ($self->{format_signature} == $self->calcCRC(pack("H*", "02FF20" . "0413" . "4413"))) {
+      # Info, Volume, Target Volume
+      # convert into full frame
+      $applicationlayer =   pack("H*", "02FF20") . substr($applicationlayer, 5, 2) # Info
+                          . pack("H*", "0413") . substr($applicationlayer,7,4) # volume
+                          . pack("H*", "4413") . substr($applicationlayer,11,4); # target volume 
+      $offset = 0;
+    } elsif ($self->{format_signature} == $self->calcCRC(pack("H*", "02FF20" . "0413" . "523B"))) {
+      # Info, Volume, Max flow
+      # convert into full frame
+      $applicationlayer =   pack("H*", "02FF20") . substr($applicationlayer, 5, 2) # Info
+                          . pack("H*", "0413") . substr($applicationlayer,7,4) # volume
+                          . pack("H*", "523B") . substr($applicationlayer,11,2); # max flow 
+      $offset = 0;
+    } elsif ($self->{format_signature} == $self->calcCRC(pack("H*", "02FF20" . "0413" . "4413" . "615B" . "6167"))) {
+      # Info, Volume, Max flow, flow temp, external temp
+      # convert into full frame
+      $applicationlayer =   pack("H*", "02FF20") . substr($applicationlayer, 5, 2) # Info
+                          . pack("H*", "0413") . substr($applicationlayer,7,4) # volume
+                          . pack("H*", "4413") . substr($applicationlayer,11,4) # target volume 
+                          . pack("H*", "615B") . substr($applicationlayer,15,1) # flow temp 
+                          . pack("H*", "6167") . substr($applicationlayer,16,1); # external temp
+      $offset = 0;
+    } else {
+      $self->{errormsg} = 'Unknown Kamstrup compact frame format';
+      $self->{errorcode} = ERR_UNKNOWN_COMPACT_FORMAT;
+      return 0;
+    }
+    if ($self->{full_frame_payload_crc} != $self->calcCRC($applicationlayer)) {
+      $self->{errormsg} = 'Kamstrup compact frame format payload CRC error';
+      $self->{errorcode} = ERR_CRC_FAILED;
+      return 0;
+    }
+  } elsif ($self->{cifield} == CI_SND_UD_MODE_1 || $self->{cifield} == CI_SND_UD_MODE_2) {
+    $self->{sent_from_master} = 1;
+    # The  EN1434-3  defines  two  possible  data  sequences  in  multibyte  records.  
+    # The  bit  two (counting begins with bit 0, value 4), which is called M bit or Mode bit, 
+    # in the CI field gives an  information  about  the  used  byte  sequence  in  multibyte  data  structures.  
+    # If  the  Mode  bit  is not set (Mode 1), the least significant byte of a multibyte record is transmitted first, 
+    # otherwise (Mode  2)  the  most  significant  byte.  
+    # The  Usergroup  recommends  to  use  only  the  Mode  1  in future applications.
+    $self->{mode_bit} = $self->{cifield} & 4; 
+  } else {
+    # unsupported
+    $self->decodeConfigword();
+    $self->{errormsg} = 'Unsupported CI Field ' . sprintf("%x", $self->{cifield}) . ", remaining payload is " . unpack("H*", substr($applicationlayer,$offset));
+    $self->{errorcode} = ERR_UNKNOWN_CIFIELD;
+    return 0;
+  }
+  $self->{statusstring} = join(", ", $self->state2string($self->{status}));
+
+  $self->decodeConfigword();
+  
+  $self->{encryptionMode} = $encryptionModes{$self->{cw_parts}{mode}};
+  if ($self->{cw_parts}{mode} == 0) {
+    # no encryption
+    if (!$self->{isEncrypted}) {
+      $self->{decrypted} = 1;
+    }
+    $payload = substr($applicationlayer, $offset);
+  } elsif ($self->{cw_parts}{mode} == 5 || $self->{cw_parts}{mode} == 7) {
+    # data is encrypted with AES 128, dynamic init vector
+    # decrypt data before further processing
+    $self->{isEncrypted} = 1;
+    $self->{decrypted} = 0;
+
+    if ($self->{aeskey}) { 
+      if ($hasCBC) {
+        # payload can be only partially encrypted.
+        # decrypt only the encrypted part
+        my $encrypted_length = $self->{cw_parts}{encrypted_blocks} * 16;
+        #printf("encrypted payload %s\n", unpack("H*", substr($applicationlayer,$offset, $encrypted_length)));
+        if ($self->{cw_parts}{mode} == 5) {
+          eval {
+            $payload = $self->decrypt_mode5(substr($applicationlayer, $offset, $encrypted_length)); 
+          };
+        } else {
+          # mode 7
+          if ($hasCMAC) {
+            $offset++; # account for codeword byte 3
+            eval {
+              $payload = $self->decrypt_mode7(substr($applicationlayer, $offset, $encrypted_length)); 
+            }
+          } else {
+            $self->{errormsg} = 'Digest::CMAC is not installed, please install it (sudo cpan -i Digest::CMAC)';
+            $self->{errorcode} = ERR_CIPHER_NOT_INSTALLED;
+            return 0;          
+          }
+        }
+        if ($@) {
+          #fatal decryption error occurred
+          $self->{errormsg} = "fatal decryption error for mode " . $self->{cw_parts}{mode} . ": $@";
+          $self->{errorcode} = ERR_DECRYPTION_FAILED;
+          return 0;
+        }
+        # add unencrypted payload 
+        $payload .= substr($applicationlayer, $offset+$encrypted_length);
+        #printf("decrypted payload %s\n", unpack("H*", $payload));
+        if (unpack('n', $payload) == 0x2f2f) {
+          $self->{decrypted} = 1;
+        } else {
+          # Decryption verification failed
+          $self->{errormsg} = sprintf('Decryption mode %d failed, wrong key?', $self->{cw_parts}{mode});
+          $self->{errorcode} = ERR_DECRYPTION_FAILED;
+          #printf("%x\n", unpack('n', $payload));
+          return 0;
+        }
+      } else {
+        $self->{errormsg} = 'Crypt::Mode::CBC is not installed, please install it (sudo cpan -i Crypt::Mode::CBC)';
+        $self->{errorcode} = ERR_CIPHER_NOT_INSTALLED;
+        return 0;
+      }
+    } else {
+      $self->{errormsg} = 'encrypted message and no aeskey provided';
+      $self->{errorcode} = ERR_NO_AESKEY;
+      return 0;
+    }
+  } else {
+    # error, encryption mode not implemented
+    $self->{errormsg} = sprintf('Encryption mode %x not implemented', $self->{cw_parts}{mode});
+    $self->{errorcode} = ERR_UNKNOWN_ENCRYPTION;
+    $self->{isEncrypted} = 1;
+    $self->{decrypted} = 0;
+    return 0;
+  }
+  
+  if ($self->{cifield} == CI_RESP_SML_4 || $self->{cifield} == CI_RESP_SML_12) {
+    # payload is SML encoded, that's not implemented
+    $self->{errormsg} = "payload is SML encoded, can't be decoded, SML payload is " . unpack("H*", substr($applicationlayer,$offset));
+    $self->{errorcode} = ERR_SML_PAYLOAD;
+    return 0;
+  } else {
+    return $self->decodePayload($payload);  
+  }
+  
+}
+
+sub decodeLinkLayer($$)
+{
+  my $self = shift;
+  my $linklayer = shift;
+
+  if (length($linklayer) < TL_BLOCK_SIZE + $self->{crc_size}) {
+    $self->{errormsg} = "link layer too short";
+    $self->{errorcode} = ERR_LINK_LAYER_INVALID;
+    return 0;
+  }
+  ($self->{lfield}, $self->{cfield}, $self->{mfield}) = unpack('CCv', $linklayer);
+  $self->{afield} = substr($linklayer,4,6);
+  $self->{afield_identno} = substr($self->{afield}, 0, 4);
+  $self->{afield_id} = sprintf("%08d", $self->decodeBCD(8,substr($linklayer,4,4)));
+  ($self->{afield_ver}, $self->{afield_type}) = unpack('CC', substr($linklayer,8,2));
+  
+  #printf("lfield %d\n", $self->{lfield});
+
+  if ($self->{frame_type} eq FRAME_TYPE_A) {
+    if ($self->{crc_size} > 0) {
+      $self->{crc0} = unpack('n', substr($linklayer,TL_BLOCK_SIZE, $self->{crc_size}));
+    
+      #printf("crc0 %x calc %x\n", $self->{crc0}, $self->calcCRC(substr($linklayer,0,10)));
+    
+      if ($self->{crc0} != $self->calcCRC(substr($linklayer,0,TL_BLOCK_SIZE))) {
+        $self->{errormsg} = "CRC check failed on link layer";
+        $self->{errorcode} = ERR_CRC_FAILED;
+        #print "CRC check failed on link layer\n";
+        return 0;
+      }
+    }
+
+    # header block is 10 bytes + 2 bytes CRC, each following block is 16 bytes + 2 bytes CRC, the last block may be smaller
+    $self->{datalen} = $self->{lfield} - (TL_BLOCK_SIZE - 1); # this is without CRCs and the lfield itself
+    $self->{datablocks} = int($self->{datalen} / LL_BLOCK_SIZE);
+    $self->{datablocks}++ if $self->{datalen} % LL_BLOCK_SIZE != 0;
+    $self->{msglen} = TL_BLOCK_SIZE + $self->{crc_size} + $self->{datalen} + $self->{datablocks} * $self->{crc_size};
+      
+    #printf("calc len %d, actual %d\n", $self->{msglen}, length($self->{msg}));
+    $self->{applicationlayer} = $self->removeCRC(substr($self->{msg},TL_BLOCK_SIZE + $self->{crc_size}));
+  
+  } else {
+    # FRAME TYPE B
+    # each block is at most 129 bytes long.
+    # first contains the header (TL_BLOCK), L field and trailing crc
+    # L field is included in crc calculation
+    # each following block contains only data and trailing crc
+    if (length($self->{msg}) < $self->{lfield}) {
+      $self->{errormsg} = "message too short, expected " . $self->{lfield} . ", got " . length($self->{msg}) . " bytes";
+      $self->{errorcode} = ERR_MSG_TOO_SHORT;
+      return 0;
+    }    
+    
+    
+    my $length = 129;
+    if ($self->{lfield} < $length) {
+      $length = $self->{lfield};
+    }
+    if ($self->{crc_size} > 0) {
+      $length -= $self->{crc_size};
+      $length++; # for L field
+      #print "length: $length\n";
+      $self->{crc0} = unpack('n', substr($self->{msg}, $length, $self->{crc_size}));
+      
+      #printf "crc in msg %x crc calculated %x\n", $self->{crc0}, $self->calcCRC(substr($self->{msg}, 0, $length));
+      if ($self->{crc0} != $self->calcCRC(substr($self->{msg}, 0, $length))) {
+        $self->{errormsg} = "CRC check failed on block 1";
+        $self->{errorcode} = ERR_CRC_FAILED;
+        return 0;
+      }
+    }
+    
+    $self->{datablocks} = int($self->{lfield} / 129);
+    $self->{datablocks}++ if $self->{lfield} % 129 != 0;
+    # header block is 10 bytes, following block 
+    $self->{datalen} = $self->{lfield} - (TL_BLOCK_SIZE - 1) - ($self->{datablocks} * $self->{crc_size}) ; # this is with CRCs but without the lfield itself
+    $self->{msglen} = $self->{lfield};
+
+    if ($self->{datablocks} == 2) {
+      # TODO
+    } else {
+      $self->{applicationlayer} = substr($self->{msg}, TL_BLOCK_SIZE, $length - TL_BLOCK_SIZE); # - $self->{crc_size});
+    }
+  }
+
+  if (length($self->{msg}) > $self->{msglen}) {
+    $self->{remainingData} = substr($self->{msg},$self->{msglen});
+  } elsif (length($self->{msg}) < $self->{msglen}) {
+    $self->{errormsg} = "message too short, expected " . $self->{msglen} . ", got " . length($self->{msg}) . " bytes";
+    $self->{errorcode} = ERR_MSG_TOO_SHORT;
+    return 0;
+  }
+  
+  
+  # according to the MBus spec only upper case letters are allowed.
+  # some devices send lower case letters none the less
+  # convert to upper case to make them spec conformant
+  $self->{manufacturer} = uc($self->manId2ascii($self->{mfield}));
+  $self->{typestring} =  $validDeviceTypes{$self->{afield_type}} || 'unknown';
+  return 1;
+}
+
+sub encodeLinkLayer($)
+{
+  my $self = shift;
+
+  my $linklayer = pack('CCv', $self->{lfield}, $self->{cfield}, $self->{mfield});
+  ($self->{lfield}, $self->{cfield}, $self->{mfield}) = unpack('CCv', $linklayer);
+  $self->{afield} = substr($linklayer,4,6);
+  $self->{afield_id} = sprintf("%08d", $self->decodeBCD(8,substr($linklayer,4,4)));
+  ($self->{afield_ver}, $self->{afield_type}) = unpack('CC', substr($linklayer,8,2));
+  
+  #printf("lfield %d\n", $self->{lfield});
+
+  if ($self->{frame_type} eq FRAME_TYPE_A) {
+    if ($self->{crc_size} > 0) {
+      $self->{crc0} = unpack('n', substr($linklayer,TL_BLOCK_SIZE, $self->{crc_size}));
+    
+      #printf("crc0 %x calc %x\n", $self->{crc0}, $self->calcCRC(substr($linklayer,0,10)));
+    
+      if ($self->{crc0} != $self->calcCRC(substr($linklayer,0,TL_BLOCK_SIZE))) {
+        $self->{errormsg} = "CRC check failed on link layer";
+        $self->{errorcode} = ERR_CRC_FAILED;
+        #print "CRC check failed on link layer\n";
+        return 0;
+      }
+    }
+
+    # header block is 10 bytes + 2 bytes CRC, each following block is 16 bytes + 2 bytes CRC, the last block may be smaller
+    $self->{datalen} = $self->{lfield} - (TL_BLOCK_SIZE - 1); # this is without CRCs and the lfield itself
+    $self->{datablocks} = int($self->{datalen} / LL_BLOCK_SIZE);
+    $self->{datablocks}++ if $self->{datalen} % LL_BLOCK_SIZE != 0;
+    $self->{msglen} = TL_BLOCK_SIZE + $self->{crc_size} + $self->{datalen} + $self->{datablocks} * $self->{crc_size};
+      
+    #printf("calc len %d, actual %d\n", $self->{msglen}, length($self->{msg}));
+    $self->{applicationlayer} = $self->removeCRC(substr($self->{msg},TL_BLOCK_SIZE + $self->{crc_size}));
+  
+  } else {
+    # FRAME TYPE B
+    # each block is at most 129 bytes long.
+    # first contains the header (TL_BLOCK), L field and trailing crc
+    # L field is included in crc calculation
+    # each following block contains only data and trailing crc
+    if (length($self->{msg}) < $self->{lfield}) {
+      $self->{errormsg} = "message too short, expected " . $self->{lfield} . ", got " . length($self->{msg}) . " bytes";
+      $self->{errorcode} = ERR_MSG_TOO_SHORT;
+      return 0;
+    }    
+    
+    
+    my $length = 129;
+    if ($self->{lfield} < $length) {
+      $length = $self->{lfield};
+    }
+    if ($self->{crc_size} > 0) {
+      $length -= $self->{crc_size};
+      $length++; # for L field
+      #print "length: $length\n";
+      $self->{crc0} = unpack('n', substr($self->{msg}, $length, $self->{crc_size}));
+      
+      #printf "crc in msg %x crc calculated %x\n", $self->{crc0}, $self->calcCRC(substr($self->{msg}, 0, $length));
+      if ($self->{crc0} != $self->calcCRC(substr($self->{msg}, 0, $length))) {
+        $self->{errormsg} = "CRC check failed on block 1";
+        $self->{errorcode} = ERR_CRC_FAILED;
+        return 0;
+      }
+    }
+    
+    $self->{datablocks} = int($self->{lfield} / 129);
+    $self->{datablocks}++ if $self->{lfield} % 129 != 0;
+    # header block is 10 bytes, following block 
+    $self->{datalen} = $self->{lfield} - (TL_BLOCK_SIZE - 1) - ($self->{datablocks} * $self->{crc_size}) ; # this is with CRCs but without the lfield itself
+    $self->{msglen} = $self->{lfield};
+
+    if ($self->{datablocks} == 2) {
+      # TODO
+    } else {
+      $self->{applicationlayer} = substr($self->{msg}, TL_BLOCK_SIZE, $length - TL_BLOCK_SIZE); # - $self->{crc_size});
+    }
+  }
+
+  if (length($self->{msg}) > $self->{msglen}) {
+    $self->{remainingData} = substr($self->{msg},$self->{msglen});
+  } elsif (length($self->{msg}) < $self->{msglen}) {
+    $self->{errormsg} = "message too short, expected " . $self->{msglen} . ", got " . length($self->{msg}) . " bytes";
+    $self->{errorcode} = ERR_MSG_TOO_SHORT;
+    return 0;
+  }
+  
+  
+  # according to the MBus spec only upper case letters are allowed.
+  # some devices send lower case letters none the less
+  # convert to upper case to make them spec conformant
+  $self->{manufacturer} = uc($self->manId2ascii($self->{mfield}));
+  $self->{typestring} =  $validDeviceTypes{$self->{afield_type}} || 'unknown';
+  return 1;
+}
+
+
+sub setFrameType($$)
+{
+  my $self = shift;
+  $self->{frame_type} = shift;
+}
+
+sub getFrameType($)
+{
+  my $self = shift;
+  return $self->{frame_type};
+}
+
+sub parse($$)
+{
+  my $self = shift;
+  $self->{msg} = shift;
+  
+  $self->{errormsg} = '';
+  $self->{errorcode} = ERR_NO_ERROR;
+  
+  if (length($self->{msg}) < 12) {
+    $self->{errormsg} = "Message too short";
+    $self->{errorcode} = ERR_MSG_TOO_SHORT;
+    return 1;
+  }
+  if (substr($self->{msg}, 0, 4) eq pack("H*", "543D543D")) {
+    $self->setFrameType(FRAME_TYPE_B);
+    $self->{msg} = substr($self->{msg},4);
+  }
+  if ($self->decodeLinkLayer(substr($self->{msg},0,12)) != 0)  {
+    $self->{linkLayerOk} = 1;
+    return $self->decodeApplicationLayer();
+  }
+  return 0;
+
+}
+
+sub parseLinkLayer($$)
+{
+  my $self = shift;
+  $self->{msg} = shift;
+
+  $self->{errormsg} = '';
+  $self->{errorcode} = ERR_NO_ERROR;
+  $self->{linkLayerOk} = $self->decodeLinkLayer(substr($self->{msg},0,12));
+  return $self->{linkLayerOk};
+}
+
+sub parseApplicationLayer($)
+{
+  my $self = shift;
+
+  $self->{errormsg} = '';
+  $self->{errorcode} = ERR_NO_ERROR;
+  return $self->decodeApplicationLayer();
+}
+
+1;