text: <s>[INST] PowerFlex 700 drive Modbus communication network with Prosoft Module 3100-MCM plus PLC -5 remote I/O Hi,I am having a PLC-5 system and prosoft module MCM-3100. . We are connecting the PF700VC drive with 20-COMM-H module on modbus RTU RS485 communication network. But don't know how to write the prosoft logic , what are regsister addresses need to configure or use in the PLC-5 and prosoft logic. If anybody has already done this type of communication , please guide me.I am trying to write  Start command, stop command, Speed reference to drive and reading Drive status for start/stop and fault, speed feedabck and output current. [/INST] I realize this is an old post and am posting in the event others search for a similar solution. For OP's scenario, 3100-MCM sample ladder ProSoft provides is 99% ready to read/write to a 20-COMM-H. The only changes needed would be to ensure the R/G/S are correct in the BTR/BTW, make the proper changes to the Modbus ports being used, and then create the Modbus Master commands that will communicate with the 20-COMM-H. If you have any questions, please don't hesitate to contact our Technical Support group. Chris Hines ProSoft Technology \\n </s>