| 摘要 |
PURPOSE:To make a fail-safe processor system practicable by converting always processor bus signals into analogs and also by comparing converted analog values with reference values through a fail-safe analog comparator. CONSTITUTION:At normal time, double series microcomputers 10 and 20 operate almost synchronously and the outputs coming from digital-analog converters 30A and 30B are nearly the same level having little deviation. Thus a failure detection relay FSAC detects that the comparator 31 normally oscillates. If data discrepancies occur, the outputs values coming from digital-analog converters 30A and 30B are so different that the comparator 31 stops oscillating. Accordingly, the failure detection relay FDA, being lacking in an exciting function, can detect any fail-safe failure of the double series microcomputers. |
