Connection between pc and mitisibushi fx3u-64m plc via usb-sc09-fx cable adapter

[how]

Dear all,
I have fx3u series plc with built in rs422 port and usb-sc09-fx cable. I have a a hyperterminal like application to send and receive message between the pc and the plc. I know the cable work because it is fine when I load the ladder from gx work 2 to plc and when I read back. I used a simple ladder using RS instruction with non protocol communication given as example in the plc manual. But I can not communicate with plc. I have checked the baud rate and related things but still I didn't get a solution. Please help

 

[goghie]

RS command does not work with Programming port.

 

[how]

Thank you very much. I was struggling with it. Then any one knows which command works

 

[parky]

As far as I know the protocol of the programming port is not documented, there are probably some code out there i.e. VB or C that somebody has tried, the alternative is to fit the 232 BD board this gives you simple 232 comms as well as programming capability.

 

[how]

Currently I can't add any module. But I saw a commercial automation system that uses the built in port for both the programming and for the scada in fact that plc is not exactly fx3u-64 but it was fx series . Dear parky, can you point me those vb or c implementations?

 

[how]

I am struggling with computer link dedicated protocol. When I send a message from the hyperterminal I am getting NAK 15H. Does this show that I am closer. Can we say that at least the plc respond? I should fight this because getting even a cheap device like external communication module here is a nightmare

 

[how]

Any help?

 

[parky]

The FX series is long past it's usable date & is not supported but I have no idea if the protocol for the programming port is the same as the FX series.
However, this is a link to some information but it is for the FX0 so may be the same,

Mitsubishi FX0N series PLC programming port communication protocol example

fx protocol, fx plc, px serial frame

www.coder96.com

 

[how]

Thank you parky, I will try the code provided there.