Hi Joe,
I will try with the method used in the help tutorial.
Another clarification I need from you. In Unitronics PLC for RS485 in built port has D+, D-, SG and GND only. In power supply it has TX+, TX-, RX+, RX-,SG. So I connected TX+ AND RX+ together and connected PLC side to D+. TX- and RX- together connected with D-. and SG for SG in PLC. Is this correct?