M91 2 R2C Modbus comunication

[knt2009]

Dear all,

 

I am new on this forum, even though I an using the Unitronics PLC for more than 10 years now. I have a problem with the RS485 MODBUS communication to the frequency converter. After I have established the communication to the converter I am not able to connect to the PLC with the programing computer. I have tried all possible settings of the comunication protocol bur without sucess.

 

Can somebody give me some advice what to do? Is there a possiblity to do somehow a reset of the PLC?

 

I am using M91 2 R2C

 

Thanks and best regards,

[AlexUT]

It seems that you use the same COM port to communicate to frequency converter and PC.

PC use PCOM protocol to connect to PLC.

Frequency converter use MODBUS protocol.

Only one protocol can be active, not both.

You can send your project to support@unitronics.com for review.

[Joe Tauser]

This is a much easier application with a V130 and an add-in COM port.  M91s are a pain in the butt to do serial communications.

 

Joe T.