This rugged device reliably solves a host of communication problems. It converts two- or four-wire RS485 to RS232 (and back again), and an optional module converts either of these formats into fiber optic, Bidirectionally. The Unicom 2500 communicates at a rate of up to 115 kilo baud, and it even increases the throughput of two-wire RS485 mode. Its opto-isolation protects your valuable equipment and buses from destructive spikes and surges of up to 2500 volts. The Unicom also has a DTE/DCE switch that eliminates the need for a null modem. A nifty little feature that can’t be fully appreciated until it’s needed.