The Force Model 2769 increases the transmission range (compared to copper) of RS-232 or RS-422 data signals in a linear bus topology. Each unit is a complete daisy-chain transceiver capable of full-duplex data transmission. Operating over an optical loss range of 21 dB, the link is DC coupled and will handle bursty data or long periods of time between data bits. A backup power source, NiCd batteries, allow continuous operation for up to 24 hours after a loss of primary, +12 Volt DC power to the unit. TM Single-mode 1310 nm optics and ST optical connectors ensure reliable performance. The unit is available in a 4RU rack-mount configuration in addition to the rugged stand-alone module. These units are ideal for polled security systems, computer LAN, process control, and I.T.S. applications.