... -MMDescription: The Ci-sf120 series is designed for use in optical RS232/485/422 general serial networks. Feature with ... one electrical interface. The modems provide fiber optic connection in point to point, star, daisy chain topologies networks.SpecificationElectrical interfaceRS232/ ... support for RXD, TXD, GND 3-line approach to work;RS422 support for RX-, RX +, TX-, TX + full-duplex mode;RS485 ...