DATA TRANSMISSION SYSTEM USES CMOS.

A data transmission system has been developed which, although originally intended to fill the need for a low-cost highway telephone and signaling system, is showing a great deal of promise in other applications. Apart from novel aspects of the system design, the circuit is interesting in that it is one of the first examples of TTL circuitry being replaced by CMOS. The system can have up to 184 inputs which are scanned sequentially. The resulting data are transmitted down a pair of wires to a receiver where they are checked, decoded and divided into 184 outputs. The system can really be looked at as a 2-wire replacement for a 184-core cable. In a practical system, it would be usual to install a transmitter and a receiver at each end of the link, making two-way, or duplex, communication possible.