Communication Redundancy board is RS 422/485 redundancy switch. It has optical isolation that protects one segment of network from problems that arises on the other. Data can be switched over Output from either of the port depending on the corresponding data coming from the terminal server port. Supports for RS 422/RS 485-4 Wire/ RS 485-2Wire. (Jumper Link selectable). Opto-isolation : 1.5KV Operation : Point to Point (RS 422), Multi-drop Full Duplex (RS 485-4 W), Multi-drop Half Duplex (RS 485-2 W) Speed : 9.6Kbps TO 38.4 Kbps Channels : 2 CHANNELS LED Indications : Power, Transmit and Receive POWER : 230VAC SIZE : 107[W] * 245[L]* 45[H] mm