Equipment control system with fiber optic coupled remote control

Claim 1

A fiber optic linked remote control system for transmitting electrical analog data signals from a remote control unit via a fiber optic link to receiving means located at the equipment to be controlled, said remote control system including: a remote control station having a manual control section containing function selecting means, output voltage varying means, and a spring-biased deadman switch; fiber optic transmitting circuitry coupled to said remote control station, said transmitting circuitry including modulating means for converting analog signals representing functions selected by said selecting means and voltage levels selected by said voltage varying means into a corresponding series of optical data output pulses, said transmitting circuitry further including deadman circuitry responsive to a release of said spring-biased deadman switch for canceling the output of said modulating means; a fiber optic link, the first end of said link being coupled to the output of said transmitting circuitry; fiber optic receiving circuitry coupled to the second end of said fiber optic link, said receiving circuitry including demodulating means for reconverting the optical data output pulses of said transmitting modulation means into corresponding analog signals representing functions selected by said remote station function selecting means and said output voltage varying means; and safety circuitry within said receiving circuitry and becoming activated by the canceled optical output of said transmitting circuitry produced by operation of said deadman circuitry or breaking, within said receiving circuitry, the circuitry of said analog signal corresponding to the varying output voltage selected at said remote station, and for delaying for a predetermined delay period the restoration of said varying voltage circuitry after inactivation of said deadman circuitry and corresponding restoration of said transmitting circuitry optical output.