I design a new system with PLC GEFanuc series 90-70 connected with MMI. I have to choose MMI software between Cimplicity and RSView. I put GE modbus RTU module (P/N IC697CMM711) and use it to connect to MMI. I think if i chose Cimplicity, i don't have to buy anything else, just pull a wire from modbus RTU module to PC, because cimplicity already have the modbus RTU driver. But if i chose RSView, i have to buy OPC server. Could anybody suggest that my assumption is correct or not ?