GB1063186A - Remote action control system - Google Patents

Abstract

1,063,186. Electric selective signalling. INTERNATIONAL STANDARD ELECTRIC CORPORATION. May 6, 1965 [May 6, 1964]; No. 19118/65. Heading G4H. Substations U (Fig. 2) interrogated by a control station Z via a lead b when one of the switches in the -substafcion changes state or alternatively when the control station wishes to query a substation, send reply pulses along a line a in the form of a short pulse after a short delay to indicate an answer "No" and a long pulse after a long delay to indicate the answer. " Yes." In the form shown, when one of the substations. U wishes to be interrogated by the control station an alarm is indicated at AA and the control station then scans each of the substations in turn until the address code of the alerting station is recognized by the substation. Interrogating pulses from F1 are then sent to the substation to scan each of the switches in turn, the position of each switch being indicated by a " Yes "or " No " reply along the line a. The response pulses are sent to the interrogator F1 which is inhibited from interrogating while it is receiving a pulse and the complementary pulse allowed to form therein. The response pulses are also passed to a shift register which is enabled by a comparator PE if the pulses received from the interrogator F1 are the complements of the inputs received along the line m so that the data in the shift register can be passed to a store.