Automatic fault detection system for programmable controllers - uses continuously operating arrangement generating test addresses for instruction addresses comparison

摘要

The system for locating faults in programmable controllers is applicable to rapid automatic detection and analysis of process anomalies. It is continuously operating within a controller and enables faults to be detected economically under all application conditions. An address comparator (3) connected to a microprocessor system (2) contg. integrated coupling components (2a,2b,2c) compares a test address with an actual address from a programmable controller (1). It feeds the comparison signal to a control mechanism (4) connected alternately to the microprocessor system (2) and the programmable controller (1). The microprocessor system (2) is connected to the programmable controller (1) via data (1c) and instruction (1b) buses and also to a display (D) and an operator field (E) for entering control instructions. The display may contain LEDs, segment displays, or point-matrix indicators.