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robror_

MB_CLIENT Error

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Hi there!

I'm trying to communicate a S7-1500 CPU via Modbus TCP with an CJ2 PLC using a CP1W-MODTC61 card.


I configurated the MB_Client and the CP1W-MODTC61 was also configured as the attached files show. The thing is that I could not read any data from the PLC (the registers are in the correct address and memory area) and I tried different combinations until I started to get data (with the correct values) for a moment, even with a configuration I already tried.

After that the block kept writing a 8200 error in the status word and no data was received. According to the manual that reads:

    A different Modbus request is currently being processed via the port.
    Another instance of MB_CLIENT with the same connection parameters is processing an existing Modbus request.

I can confirm that there is no other device doing a Modbus request in either the 1500 or the CJ2, and I only have one MB_CLIENT block in the entire program.

So that's where my question comes, is the CPU detecting another "ghost" request, even if there shouldn't be any? Or am I missing something in the CONNECT structure of the block?


Thanks in advance for your support!

 

 

Click to choose files

Modbus MB_CLIENT.png

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Try putting a normally closed of "BUSY" in series with "M0.7" in the "REQ" input

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