Expand leased line, polled environments without adding computer ports or communications links. Reduce line costs in your RS-232 system by using a BLACK BOX RS-232 Data Sharer to connect two devices to a single modem and phone line. The RS-232 Data Sharer features transparent operation up to 64 kbps and convenient LED monitoring. Front-panel switches enable and disable RTS on each input port. It features antistreaming circuitry to lock out any port the instant it begins to stream. The RS-232 Data Sharer is compatible with various popular IBM communications protocols, such as half-duplex Bisynchronous Communication and Synchronous Data Link Control (SDLC).