Replace Omron NT30C HMI with a Proface HMI

3 posts in this topic

I have an Omron CQM1-CPU41-V1 and a NT30C HMI. I would like to replace the NT30C with a Proface GP4301-TM.

The Proface HMI software (GP-Pro EX) has a Omron driver to communicate with the CQM1. I’ve followed the directions provided from Proface for setting up the communications in the CQM1 and the GP4301.

I also create the special cable that needs to go from the RS232 ports on the CQM1 and the GP4301.

I’m getting either a cable is disconnected or response timed out error from the GP4301.

I’ve tried various communications settings to no avail.

The last thing I’ve done is to run the RS232 cable from the NT30C into my PC and forward it out of my PC to the CQM1 using a piece of software call Termite.

What this does for me is to see what is being sent on the RS232 line.

The 1st code sent from the NT30C to the CQM1 is @00MM40 (in ASCII), the CQM1 responses and they both work fine together.

When I connect up the GP4301 in this fashion the 1st code sent out from it is @00MS5E (in ASCII). As you can see these are different and the CQM1 does not response.


Does anyone have ideas on how to get the correct code out of the GP4301?


Thank You,


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@00MM is a HostLink command, to read the PLC Model (with the 40 at the end is a CRC code)

@00MS is also a HostLink command, which is used to read the current status of the PLC (whether it's in Stop/Program, Monitor, or Run Mode).

None of these are a prerequisite to enable communications between the HMI and PLC. The PLC is basically passive, waiting for any request from the connected device, and it will respond accordingly. So that's not the issue here.

Maybe you can attach your cable pinout configs, and also communication settings you've done on both the NT30 and the Proface

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Thank you for the information. I did some more work with the cabling and found out that in addition to jumping RTS and CTS on the HMI I also need to jumper DTR and DSR in the HMI. When I did that it started working.

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