Method and Apparatus for Diagnostic Coverage of Safety Components

摘要

A method and system for diagnostic coverage of safety components monitors the state of a safety chain and each of the safety devices in the chain. A fault condition is detected if one of the safety devices indicates that the safety chain should be open but the safety chain indicates that it is closed. In order to prevent an inadvertent reset of the fault condition by opening the safety chain via a second safety device, the fault condition is latched until the monitoring system verifies that the faulty safety device has been corrected.