i never connect a roboter this a plc over device net, but often simple fieldbuscoupler like a WAGO coupler. To configure the system it schould be the same.
Create in the eio.cfg lines like this
EIO_UNIT_TYPE:
VondorId, DeviceType and ProductId must be from the PLC. You can get the information maybe from an Allen Bradley eds-file.
The eds-file for the S4C+ is on the cd and below the text.