Modbus Serial Write to a single register

[harry10138]

Hi, I'm trying to write command to my energy meter UEM80-4D R, the query message is correct, I try to change the bps on the meter through writing the command, but the setting on the meter didn't change, I do not know how to get the response message too. Any examples of write single holding register by using the Modbus library will be great.

Thank you 

[GerdW]

Hi harry,

does your energy meter even support "Write Single Register" (as the error message suggests)?

[harry10138]

Hi, yes it does support, I write the command based on the example on the datasheet of the meter.

[GerdW]

Hi harry,

those images always show function code 10h=16d…

You use that function code 10h=16d when creating your own "message" indicator.

But you still use that WriteSingleHoldingRegister function! That function is using the ModBus function code 6 - and then your device responds with "unsupported function code"! Have you tried to write to multiple registers?

[harry10138]

Hi, I just tried what you have suggested, but i still encounter the error. 

[GerdW]

Hi harry,

what happens when you send the bytes of that example (Capture.png from message #3) to your device using a simple VISAWrite command?