|February 1955, Vol. 138, No. 6||Railway and Locomotive Engineering (New York)||Page 10|
Equipment and Supplies
High-speed signal control
The General Railway Signal Company has announcedSyncroscan, a new form of coded remote control combining relay and electronic operation, which is said to have outstanding characteristics of speed and capacity for both controls and indications. It makes possible centralized control of large, heavy-traffic territories of multiple track and complex interlockings—without delays and with a minimum of equipment.
The basic Syncroscan control system handles 64 stations with seven two-position (e.g., switch or signal) controls per station. With fewer stations, more controls per station are possible. Even this capacity may be substantially increased by addition of a relatively few relays and a carrier transmitter at the control office. A control cycle of 1½ seconds transmits complete control information for all functions at nay field station.
The Syncroscan indication system is electronic, has not inherent limit on capacity, and transmits as many indications as required, at a basic rate of 100 per second. Operating by carrier, Syncroscan indication facilities are completely independent of the control system, so indications are transmitted simultaneously with controls. Moreover, indication does not involve shunting of the line at any time. By using carrier for controls as well as indications, it is possible to eliminate all requirements for physical line, and to operate the system, both control and indication, over lines already existing for other purposes.
Power requirements for electronic equipment at a field station are less than 100 watts, a reasonable load for emergency supply. If indication equipment fails at a field station, only indications for that station are lost. Controls for that station, and indications for other stations, continue to function.