What is your code? Why don't the snippets from the docs of Tibrco::Rv work for you? Should be (blindy copying from POD since i've never used this module):

use Tibco::Rv;

my ( $rv ) = new Tibco::Rv(
      service => $service,
      network => $network,
      daemon => $daemon
);

my ( $msg ) = $rv->createMsg;
$msg->addString( field1 => 'myvalue' );
$msg->addString( field2 => 'myothervalue' );
$msg->sendSubject( 'ABC' );

$rv->send( $msg );
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