Dataforth's new LDM2485A/B Series of high speed, RS-232 to RS-485 interface converters turn PCs, terminals, and other RS-232 devices into powerful RS-485 workstations. Both models conform to the EIA RS-485 standard. Operating asynchronously over 2 or 4 wires, at data rates up to 115.2 kbps, these compact converters let RS-232 machines "talk" with up to 50 addressable devices in a multipoint polling environment. Distances of up to 5000 feet are possible at lower data rates. And they feature 600W of built-in silicon avalanche diode surge protection to keep critical applications up and running Five separate configuration parameters (carrier control, RTS/CTS delay, receive impedance, transmit-off impedance, and echo) make it easy to fine tune the converters to demanding multipoint applications. For example, the carrier may be continuous or "controlled by RTS", RTS/CTS delay may be 0 or 8msec, operation may be with or without "echo". Configuration is simple using on-board DIP switches. Power requirements for the devices are also simplified. The LDM2485A/B converters draw power from the RS-232 or EIA-574 data and control signals; no AC power or batteries are needed. The miniature LDM2485A measures 2.66"x2.10"x0.73" and has a DB-25 connector for RS-232 environments. The ultra-miniature LDM2485B measures only 2.50"x1.20"x0.75" and has a DB-9 connector for EIA-574. Both models have several options for twisted pair connection.