LDM30-S

The LDM30-S is a General-purpose Limited Distance Modem allows video display terminals (VDTs) and other RS-232 devices to be connected over distances sufficient to cover any industrial or institutional complex of buildings. The device is designed for full-duplex, asynchronous operation over two, DC-continuity, non-loaded, twisted-wire pairs. Through special high-speed optically-coupled circuits they may communicate at data rates up to 57,600baud. The self-powered unit uses 12VAC from a wall-mounted transformer while the host-powered unit takes ±DC power from pins 9 and 10 of the RS-232 connector. The modem circuits and consequently, the host device are protected from electrical transients due to lightning strikes or operation of heavy industrial equipment.