Condition responsive system with test means

Claim 1

A SUPERVISORY SYSTEM, COMPRISING A MASTER STATION INCLUDING A SCANNER AND INCLUDING A MOTOR FOR DRIVING THE SCANNER, A PLURALITY OF INDICATOR CIRCUITS WITH WHICH THE SCANNER MAKES SUCCESSIVE CONNECTION, EACH INDICATOR CIRCUIT CONSISTING OF A PNP TRANSISTOR HAVING A BASE, EMITTER, AND COLLECTOR ELECTRODES, AN NPN TRANSISTOR HAVING A BASE, EMITTER, AND COLLECTOR ELECTRODES, AND A LAMP, THE COLLECTOR ELECTRODE OF THE PNP TRANSISTOR BEING CONNECTED TO THE BASE ELECTRODE OF THE NPN TRANSISTOR, THE COLLECTOR ELECTRODE OF THE NPN TRANSISTOR BEING CONNECTED TO THE PHASE OF THE PNP TRANSISTOR TO PROVIDE A NEGATIVE POTENTIAL TO LATCH THE PNP TRANSISTOR IN CONDUCTING CONDITION, THE LAMP BEING CONNECTED AT ONE END OF THE EMITTER OF THE NPN TRANSISTOR AND AT THE OTHER END TO A COMMON POINT BETWEEN THE COLLECTOR OF THE PNP TRANSISTOR AND THE BASE OF THE NPN TRANSISTOR, A REMOTE STATION CORRESPONDING TO EACH OF THE INDICATOR CIRCUITS AND INCLUDING A MOTOR OPERATING ON LOCAL POWER, THE MASTER STATION MOTOR, THE ING AT A SLOWER RATE THAN THE REMOTE STATION MOTOR, THE REMOTE STATION MOTOR STOPPING A PERIOD OF TIME BEFORE THE COMPLETION OF A SCANNER ROTATION, MEANS TRANSMITTING A STARTING SIGNAL TO THE REMOTE STATION AT THE START OF A SCANNER ROTATION, WIRES CONNECTING EACH REMOTE STATION TO THE MASTER STATION, SAID WIRES INCLUDING A FIRST WIRE HAVING A NEGATIVE ELECTRICAL CHARGE, A SECOND WIRE HAVING A POSITIVE ELECTRICAL CHARGE, AND A THIRD WIRE CONNECTING THE REMOTE STATION TO THE SCANNER, A STATUS SWITCH IN EACH REMOTE STATION, EACH INDICATOR CIRCUIT BEING RESPONSIVE TO ONE TYPE OF SIGNAL FROM A STATUS SWITCH TO REGISTER A FIRST CONDITION AND BEING RESPONSIVE TO ANOTHER TYPE OF SIGNAL FROM THE STATUS SWITCH TO REGISTER A SECOND CONDITION, AND MEANS ASSOCIATED WITH EACH REMOTE STATION TO CONNECT THE STATUS SWITCH OF THAT REMOTE STATION TO THE SCANNER ONLY AT THE TIME THAT THE SCANNER MAKES CONTACT WITH THE INDICATOR CIRCUIT CORRESPONDING TO THAT REMOTE STATION, THE STATUS SWITCH CONNECTING ONE OF THE FIRST AND SECOND WIRES TO THE THIRD WIRE, AND MEANS FOR APPLYING SELECTIVELY TO THE SCANNER A CONTINUOUS SIGNAL SIMILAR TO EITHER OF THE TWO SIGNALS WHICH WOULD BE RECEIVED FROM A STATUS SWITCH IN TWO CORRESPONDING CONDITIONS.