DA70A ModBus TCP/IP Slave Communication

[hoguegregplc]

CR3000 HMI ModBus TCP/IP Master has gotten erratic after increasing block size to 24 at DA70A in Protocol 1. What should a practical guide be for block assignment? Will splitting into dual Protocols help?

 

[Ken Roach]

Welcome to the PLCTalk forum community !

Please clarify: is your DA70 initiating the comms to a "slave" peer, or is it answering requests from another device ?

Can you describe what you consider to be "erratic" ? Is the reply time changing, or is your client seeing a timeout ?

24 registers should be trivial to read or write with Modbus/TCP.

What kind of device is the other device ?

 

[hoguegregplc]

What i found was that I completed the 40000 mapping of Data Tags in the Communications protocol of the DA70A to match all of those entered in the CR3000 Data Tags, and the erratic display at the CR3000 has been eliminated.

I did not think the Communications protocol omission at the controller would interfere with the HMI, but I no longer can duplicate the error seen (failed button actions, numeric displays flashing blank) with the 40000 registers unassigned. Would this mapping correction really fix a problem?