c200h modbus slave - my pc a modbus master

Hello everyone. I've just bought myself a beautiful white vintage from 1992 Omron c200h cpu 43. I want to learn more about comms and have done some work setting up a pc to poll a modbus slave, how would I get my cpu to communicate as a modbus slave ? Do I have to do something with cx protocol ? (I have no experience of this) obviously as this is my own money I would like to not to have spend any more money

That is a really old tiger. The only way Modbus was available was with an ASCII card. I think I still have the software if you have an ASCII card.

How much did you pay for the plc?

Unfortunately not Bob, I have a sysmac net card and some sort of Controller link card that came with it, is it possible to speak directly to the PLC with my PC using that? Could I possible write some sort of protocol for it ? It has the com-04 option card.

I paid 120 GBP for it, that was with two high density I/O units, two output units and two comms cards ( unfortuantly neither of them ascii )

It is a beauty though, they built things properly in the early 90's

You could connect with Host Link to the RS232 port.

You will need the W143 manual. This explains Host Link and has an example BASIC program for connecting a computer to the plc.

You can find the manual here:

http://forums.mrplc.com/index.php?app=downloads&showfile=368

Hope this will help.

Some Hostlink examples

gtsuport said:

You could connect with Host Link to the RS232 port.

You will need the W143 manual. This explains Host Link and has an example BASIC program for connecting a computer to the plc.

You can find the manual here:

http://forums.mrplc.com/index.php?app=downloads&showfile=368

Hope this will help.

Click to expand...

Hi,
New member and first post here.
I was/am in a similar scenario with a CQM1H w/o modbus so I did a bunch of Hostlink stuff, such as opening and closing the serial port, force set/reset of bits and reading sensors (words).

The attached file is in tcl/tk, but the same logic works for any/most languages.

hope it helps,
nick