• Orion Electronics

Limited Distance Modem

Limited Distance Modem, LDM 30, is designed to allow video display terminals (VDTs) and other RS-232 devices to be connected over distances to cover any industrial or institutional complex of buildings. This is enclosed in a small aluminium enclosure saving desk space. The unit is designed for full duplex, asynchronous operation over two, DC-continuity, non-loaded twisted pairs. Baud rate can be from 1.2 Kb to 57.6 Kb and can communicate over a length of 20 km to 0.8 km respectively. Self powered 12 V AC and host powered (draws power from pin 9 and 10) models are available. Each device features a convenient DCE to DTE switch to reverse pin 2 and 3 of RS-232 connector. For installation and troubleshooting each unit have diagnostic LEDs on transmit and receive line. Both 9 pin and 25 pin D-type connector versions are available. Field connection is made through screw terminations or 4-wire modular phone jack. This provides optical isolation between input and output signals, and protects the equipment from industrial surges.