Puddle
Member
I had a similar problem with modbus a few days ago, seeing no data return and getting a time-out error. After going through all the possibilities, I think the thing I'd missed was the addressing. For holding registers you start at address 40001, so address 1 would be 40002.
Going on the assumption that in your code Cmd = 3 means that you're using function 3, this addressing shouldn't be required though. I was doing it with the modbus blocks in TIA portal, which gets the function code from a combination of mode and address, but if you can specify function then I wouldn't have thought the full address would be neccessary.
Going on the assumption that in your code Cmd = 3 means that you're using function 3, this addressing shouldn't be required though. I was doing it with the modbus blocks in TIA portal, which gets the function code from a combination of mode and address, but if you can specify function then I wouldn't have thought the full address would be neccessary.