Mitsubishi PLC Serial and Ethernet communication - help!

[michael.lewchuk 0]

Hello. I'm having a problem getting my Mitsubishi Q00J PLC with QJ71E71 Ethernet and QJ71C24 Serial to talk to my computer via what appears to be a couple of standard Q protocols (3Cx and 3Ex). I can get my Ethernet card to talk MELSEC with my PC using GX Developer, but I the PLC doesn't seem to want to respond to the 3C and 3E frames I send it. * My Ethernet card is in slot 0. * My Serial card is in slot 1. * In GX Developer PLC Parameters page, I/O Assignment tab, my Ethernet card is set as an Intelligent 32-point card at StartXY=0000, and my Serial card as an Intelligent 32-point card at StartXY=0020. My Ethernet card has no Switch X settings values, while my Serial card is set to 9600/8/N/1 protocol 1. * My Ethernet page has a Starting I/O # of 0000, Net/Group/Station 1/1/1, On-line. I have set up my Ethernet address and DNS server. My Open Settings include a TCP MELSOFT connection and a paired unpassive TCP Send/Receive buffer at port 0x0444. I had hoped to have it talking by now, or at least to be getting lots of NAKs, but it won't talk a peep to me. HELP!!!

[Crossbow 297]

What is it talking to on the PC side? How are you creating the packets?