$self->{conn} = new Net::Jabber::Client();

$self->{conn}->SetCallBacks(message=>\&InMessage,
              presence=>\&InPresence,
              iq=>\&InIQ);

my $status = $self->{conn}->Connect(
                  hostname=>$self->{Host},
                  port=>$self->{Port},
                  );

 ...

sub gpib_read {
 my $self = shift;

 print "Reading from gpib UD=$self->{ud}.\n" if ($debug);
 
 my $message = "GPIB|read|$self->{ud}";

 $self->{conn}->MessageSend(to=>'gpibserver@192.168.0.2',
           subject=>"",
           body=>$message,
           thread=>"",
           priority=>10);
 
 #Blocks until answer comes 
 $self->{conn}->Process();

 # Answer comes through callback InMessage. Is there a way
 # of expecting the answer here?
}