CIRCUIT ARRANGEMENT FOR THE VERIFICATION OF THE IN-SEQUENCE START-UP OF A DUAL-CHANNEL FAIL-SAFE MICROCOMPUTER SEQUENTIAL LOGIC SYSTEM, IN PARTICULAR FOR RAILWAY SECURITY EQUIPMENT

摘要

1. Circuit arrangement for testing the in-sequence start-up of a duel-channel fail-safe microcomputer sequential logic system, in particular for railway security equipment, having microcomputers which process the same information on two channels, the signals of which microcomputers are tested bit by bit in a plurality of comparators, no switch-off being triggered only in the event of complete, continuous correct sequencing of all bit pairs, and memories for test programmes being provided which are used at least during the time of the start-up of the microcomputer sequential logic system for test purposes, characterized in that after the start-up of the microcomputer sequential logic system at least the information provided by the one channel (MC2) for a comparator (VRn) is fed in a fixed predetermined number of successive processing steps per test programme, inverted by means of a controllable inverter (ER), and in that switching means (ZR) are provided which, at the beginning of the predetermined number of processing steps, activate the inverter (ER) and deactivate it again after the predetermined number of processing steps.