Soft error aggregation method for detection and reporting of risks in a safety instrumented system

A method performed by a processor of a safety PLC, the method comprising:

• receiving timestamped reports of soft errors that were detected by one or more I/O modules of the safety PLC;
• aggregating soft errors per type of I/O module;
• and
• reporting the aggregated, timestamped soft errors to an aggregator that is external to the safety PLC.

An aggregator communicating with one or more safety PLCs, the aggregator comprising:

• a memory configured to store instructions;
• and
• a processor disposed in communication with the memory, wherein the processor, upon execution of the instructions is configured to:
• receive an expected soft error rate for one or more types of input/output (I/O) modules over time;
• receive respective soft error data that was aggregated by respective one or more safety PLCs based on soft errors detected by I/O modules coupled to the respective one or more safety PLCs;
• determine actual soft error rates per I/O module type based on the received soft error data;
• predict soft error rates for the one or more safety PLCs per I/O module type;
• compare the actual and/or predicted soft error rates to the to the expected soft error rate per I/O module type;
• and
• take one or more actions in response to a threshold deviation between the actual and/or predicted soft error rates relative to the expected soft error rate for the corresponding I/O module type.