C Series Functional Safety modules run a range of automatic self-diagnostics that continuously check for module hardware and power supply faults. Automatic self-diagnostic faults send the module into Fail-safe Mode. The Check Module Status method in LabVIEW will return an Internal Error or Temperature Fault, depending on the fault.
Some of the automatic self-diagnostics implemented by C Series Functional Safety modules include:
DI reference compares
Redundant DO FETs
Watchdog timers custom-designed for high accuracy
Internal temperature monitoring
Power supply voltage monitoring on external supply and all internal rails
Every DO channel implements redundant FETs and meets SIL3 capability. To create additional redundancy on DO channels, only connect loads above 20 mA. If both FETs fail in the closed position, the open circuit diagnostic will return a fault.