set default interval to 30 min

diff --git a/zc-send b/zc-send
index 93dfe81..3e188ca 100755 (executable)
--- a/zc-send
+++ b/zc-send
@@ -41,7 +41,7 @@ my $raw;
 
 if ( $ARGV[0] =~ m/interval/ ) {
        # heartbeat interval
-       my $interval = $ARGV[1] || 300;
+       my $interval = $ARGV[1] || 30 * 60;
        print "set heartbeat interval to $interval s\n";
        $raw = write_parameter_frame( "\x21" => "\x04" . pack('l',$interval) );
 } elsif ( $ARGV[0] =~ m/zero/ ) {