Confused about the 1761-NET-AIC

Good day,

We are attempting to connect a Micrologics 1200 to an MDS-9810 spread spectrum radio. This is to add a station to an existing SCADA network. The existing stations all use the AIC module between the raio and the PLC. Do we really need the AIC? I am unclear about what this AIC actually does. I have read the literature and installation manual but nothing really explains exactly what this module does.

The 1761-NET-AIC is a signal converter and isolator. It converts from a differential serial signal (RS-485) to a single-ended serial signal (RS-232). It also duplicates the serial data stream on a second isolated RS-232 port.

A quick read of the MDS-9810 data sheet suggests that it has only an RS-232 port, so the 1761-NET-AIC is likely being used as an RS-232 isolator, not using the RS-485 port (that's the screw terminal connector).

I like to isolate radios from controllers; it's very cheap insurance against interference or damage.

But it's not strictly necessary to make them function, nor is a three-port device like the Net-AIC necessary.

My choice would be an RS-232 isolator from B&B Electronics like the 232OPDR.