briantet (Customer) asked a question.
ModBus Timming
How is the best way to handle timing on the ModBus RTU line to prevent data collisions? I have a BRX PLC that r/w from a solo temp controller. I have it working by adjusting the timing off on the write by 250ms and that works well. But what if I have 7 or more devices all reading and writing. How would you get your timing right? To where it operates effectively, what am I missing.
Do-more RTU client devices automatically interlock internally. You can't get it wrong. If the PLC is hitting the slave device too fast, you can set the Inter-packet Delay in the client device configuration. That controls how long the Do-more Modbus RTU Client device will wait before starting the next request.
+1 HOST_BobO
https://accautomation.ca/brx-plc-serial-communication-modbus-rtu-to-solo-process-temperature-controller/
The above post shows the communication from a BRX to the Solo. I have used the success and error bits to trigger the next communication instruction.
I hope this helps you out.
Regards,
Garry
https://accautomation.ca/series/brx-do-more-plc/