General purpose logic solver background

No reproduction or networking permitted without license from IHS 

As PLC use became more widespread, potential faults became apparent. Some of these faults included Random turn on of all inputs Random turn on of all outputs Dangerous failure of individual output 

Core memory was very susceptible to electro-magnetic coupling (EMC) 

Power supply failure resulted in spurious PLC performance 

Improper packaging of PLC components (incorrect mounting hole spacing between racks) causing EMC problems 

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