Black Box - transceiver - RS-232

Convert RS232 to Current loop to interconnect a digital 20-mA unipolar Current Loop interface to an RS-232 interface. The RS-232 to Current Loop Interface-Powered Bidirectional Converter connects to either a modem or mux. Just flip the switch to attach a terminal or computer. Your RS-232 devices are protected from dangerous transients too. Opto-isolators in both the Transmit and Receive loops keep out electrical interference.