Prosoft to PM500 SquareD comms via Modbus


Thread Starter

Norberto Florez

I have a Mvi56-mcm prosoft module, it's connected to 20 power meter PM500 SquareD via modbus (mvi56/master... PMs/Slaves). I can read the PMs using the function code 3 without problem; however, when i try write them for reset the energy values using the function code 6 nothing happens. Any suggestions? Thanks.
I'm not used to working with the Prosoft modules with SquareD, so just a couple of pointers: Have you checked if it is "allowed" to write to the registers you are addressing with the function code 6? Does the reset require a bit write (function code 5)? Have you followed through the path of where you are writing to on the PLC side, to where the data ends up in the module (based on the Write area start loction in the module buffer)? Are you aware that the addressing for bit writes requires the address to be that of the bit (not the word)? Are you setting a bit in the write buffer area, so that the written bit is actually turned on?