diff --git a/fhem/webfrontend/pgm2/01_FHEMWEB.pm b/fhem/webfrontend/pgm2/01_FHEMWEB.pm
index 4cb75884c..df9153f61 100755
--- a/fhem/webfrontend/pgm2/01_FHEMWEB.pm
+++ b/fhem/webfrontend/pgm2/01_FHEMWEB.pm
@@ -21,6 +21,7 @@ sub FW_showWeblink($$$);
 sub FW_select($$$);
 sub FW_textfield($$);
 sub FW_submit($$);
+sub FW_substcfg($$$$$$);
 sub FW_style($$);
 sub FW_roomOverview($);
 sub FW_fatal($);
@@ -851,7 +852,7 @@ FW_substcfg($$$$$$)
 {
   my ($splitret, $wl, $cfg, $plot, $file, $tmpfile) = @_;
 
-  # interprete title and label as a perl command and open accessiblity
+  # interpret title and label as a perl command and make
   # to all internal values e.g. $value.
 
   my $oll = $attr{global}{verbose};
@@ -886,9 +887,9 @@ FW_substcfg($$$$$$)
     }
   }
 
-  if($splitret) {
+  if($splitret == 1) {
     my @ret = split("\n", $gplot_script); 
-    return \@ret;
+    return (\@ret, $plot);
   } else {
     return $gplot_script;
   }
@@ -995,7 +996,7 @@ FW_showLog($)
       Log 0, $ret if($ret);
     }
     $ret = fC("get $d $file INT $f $t " . join(" ", @{$flog}));
-    $cfg = FW_substcfg(1, $wl, $cfg, $plot, $file, "<OuT>");
+    ($cfg, $plot) = FW_substcfg(1, $wl, $cfg, $plot, $file, "<OuT>");
     SVG_render($f, $t, $cfg, $internal_data, $plot);
     $__RETTYPE = "image/svg+xml";
 
diff --git a/fhem/webfrontend/pgm2/98_SVG.pm b/fhem/webfrontend/pgm2/98_SVG.pm
index 108a5d8c0..cac3cb411 100755
--- a/fhem/webfrontend/pgm2/98_SVG.pm
+++ b/fhem/webfrontend/pgm2/98_SVG.pm
@@ -112,8 +112,10 @@ SVG_render($$$$$)
     $dpoff = $ndpoff+1;
     if($l =~ m/^#/) {
       my $a = $axes[$idx];
-      $hmin{$a} = $min if(!defined($hmin{$a}) || $hmin{$a} > $min);
-      $hmax{$a} = $max if(!defined($hmax{$a}) || $hmax{$a} < $max);
+      if(defined($a)) {
+        $hmin{$a} = $min if(!defined($hmin{$a}) || $hmin{$a} > $min);
+        $hmax{$a} = $max if(!defined($hmax{$a}) || $hmax{$a} < $max);
+      }
       ($min, $max) = (99999999, -99999999);
       $hdx[$idx] = $dxp; $hdy[$idx] = $dyp;
       ($dxp, $dyp) = (\(), \());
@@ -208,6 +210,7 @@ SVG_render($$$$$)
   for my $axis ("x1y1", "x1y2") {
 
     # Round values, compute a nice step
+    next if(!defined($hmax{$axis}));
     my $dh = $hmax{$axis} - $hmin{$axis};
     my ($step, $mi, $ma);
     my @limit = (1,2,5,10,20,50,100,200,500,1000,2000,5000,10000);
@@ -279,6 +282,7 @@ SVG_render($$$$$)
   # Second loop over the data: draw the measured points
   for my $idx (0..int(@hdx)-1) {
     my $a = $axes[$idx];
+    next if(!defined($a));
     $min = $hmin{$a};
     $hmax{$a} += 1 if($min == $hmax{$a});  # Else division by 0 in the next line
     my $hmul = $h/($hmax{$a}-$min);