Nick, thanks for taking the time to explain the details. I have gained a better understanding of how OPC and DSC work.
Since I had a working project prior to the upgrade and not being very versed on how the OPC / DSC was working, I was to focused on what changes the upgrade may have made and not looking at making changes to the COM port settings. I had decided to change the Transceiver Mode from "4 wire" to "2 wire auto" and this has resolved my communication problem. During the course of the project I did switch from a RS-422 4 wire to RS-485 2 wire network but don't remember ever changing the COM settings from 4 wire to 2 wire auto since everything was still working after the switch. I basically took my initial 4 wires and tied RXD + and TXD + to Data + and RXD - and TXD - to Data - for my 2 wire network. So at this time I am not sure now how this was working in 7.1 initially but apparently something changed forcing me to switch to 2 wire.
Nick thanks again for your explanation and to all for your input in helping me resolve this problem. I appreciate everyone’s input.
