diff --git a/fhem/contrib/CULsim.pl b/fhem/contrib/CULsim.pl
new file mode 100644
index 000000000..157ca2bc2
--- /dev/null
+++ b/fhem/contrib/CULsim.pl
@@ -0,0 +1,106 @@
+#!/usr/bin/perl
+
+# Used for SCC testing.
+
+use strict;
+use warnings;
+use IO::Socket;
+
+my $port = "12345";
+my $serverSock = IO::Socket::INET->new(
+   Listen    => 5,
+   LocalAddr => 'localhost',
+   LocalPort => $port,
+   Proto     => 'tcp',
+   ReuseAddr => 1
+);
+
+die "Can't open server port: $!" if(!$serverSock);
+print "Opened port $port\n";
+
+my %selectlist;
+$selectlist{$serverSock->fileno()} = $serverSock;
+my $cnt=0;
+
+for(;;) {
+  my ($rout,$rin) = ('','');
+  map { vec($rin, $_, 1) = 1; } keys %selectlist;
+
+  my $nfound = select($rout=$rin, undef, undef, 60);
+  die "select error: $!" if($nfound < 0);
+
+  if($nfound == 0) { # timeout
+    $cnt++;
+
+    my $msg = "";
+    if($cnt % 3 == 0) {
+      $msg = "T123400A62D04";
+    } elsif($cnt % 3 == 1) {
+      $msg = "*T123400A62D04";
+    } else {
+      $msg = "**T123400A62D04";
+    }
+    foreach my $fd (keys %selectlist) {
+      if($fd != $serverSock->fileno()) {
+        my $h = $selectlist{$fd};
+        print "$h->{addr}:$h->{port}: snd >$msg<\n";
+        syswrite($h->{sock}, $msg."\n");
+      }
+    }
+  }
+
+  foreach my $fd (keys %selectlist) {
+    next if(!vec($rout, $fd, 1));
+    my $h = $selectlist{$fd};
+
+    if($fd == $serverSock->fileno()) {
+      my @clientinfo = $h->accept();
+      if(!@clientinfo) {
+        print "Accept failed: $!\n";
+
+      } else {
+        my ($port, $iaddr) = sockaddr_in($clientinfo[1]);
+        my %hash = ( port    => $port,
+                     addr    => inet_ntoa($iaddr),
+                     sock    => $clientinfo[0],
+                     partial => "");
+        print "$hash{addr}:$hash{port}: Connect\n";
+        $selectlist{$clientinfo[0]->fileno()} = \%hash;
+      }
+
+      next;
+    }
+
+    my $buf;
+    if(sysread($h->{sock}, $buf, 256) <= 0) {
+      print "$h->{addr}:$h->{port}: left us\n";
+      delete $selectlist{$fd};
+      next;
+    }
+
+    $buf = $h->{partial} . $buf;
+    while($buf =~ m/\n/) {
+      my ($cmd, $rest) = split("\n", $buf, 2);
+      print "$h->{addr}:$h->{port}: rcv >$cmd<\n";
+      my $stars;
+      $cmd =~ m/^(\**)(.*)$/;
+      $stars = $1; $cmd = $2;
+
+      my $msg = "";
+           if($cmd eq "V")   { $msg = "V 1.6".length($stars)." CUL868";
+      } elsif($cmd eq "T01") { $msg = "0000";
+      } elsif($cmd eq "?")   { $msg = "? (? is unknown) Use one of t u x";
+      } elsif($cmd eq "t")   { $msg = sprintf("%08X", (time()%86400)*125);
+      }
+      if($msg) {
+        print "$h->{addr}:$h->{port}:    =>$stars$msg<\n";
+        syswrite($h->{sock}, $stars . $msg."\n")
+      }
+
+      $buf = $rest;
+    }
+    $h->{partial} = $buf;
+
+  }
+}
+