Monitoring means for industrial process plants

摘要

System failure in the acquisition of data from a process plant such as a nuclear reactor owing to stuck signals is avoided by arranging input signals from transducers in the plant in a test pattern. The signal inputs are physically wired in the test pattern which is then decoded by either or both of a computer based system which allows for the test pattern and/or a hard wired system which mimics the input connections. Transmission of the multiplexed signals is made dynamic by provision of a polarity reverser switch (10) which alternates between signals or scans. A pattern recognition logic or a mimicing physical wiring decode the signals from the inputs or the computer system and the hard wired system respectively.