Data highway for process-controlled plant

A data highway has been devised to reduce cabling on complex process plant. Time-division-multiplexing techniques are employed, and the system provides a simple interface to a digital computer. Pulse-duration addressing is used and the data are transmitted in either analogue (pulse-duration) or digital form. A prototype system with a capacity of 500 channels has been constructed and tested on a plant. The paper describes the elements of the system and the initial results of the plant trial.