IO server I don't know about, but the V120 supports serial modbus, RS232 on either port, or RS485 on port 2. If OPC is an option, you can download a free OPC server from their website.
I connect to V120's from RSView32 with Unitronics UniOPC Server so In Touch should have no problem with bi-directional comms. The UniOPC is compliant with OPC Foundation 3.0 spec and it supports the lower specs too.