hello.....

I want to send serial command to a GV6 driver controller witch a PLC micrologix1500, I am testing from PLC to hyperterminal and the PLC is sending the correct string, but the GV6 is not detecting the message. Can somebody give a recommendation?

Thanks.

how are you testing if plc sends right string? you may be missing correct termination character so don't use ASCII display output for monitoring (like in most terminal emulators such as Hyperterminal etc.), use something that shows characters in HEX. there should be SuperMon:
http://forums.mrplc.com/index.php?autocom=downloads&showfile=575

In addition to Panic's suggestion try using hyperterminal to send strings to the GV6. Use the captured strings from the PLC and see if you get response.