4-Channel C Series Functional Safety Module—The NI-9351 works with 24 V industrial logic levels to directly connect to various sensor types, including light curtains, emergency e-stop buttons, and final elements such as relays, contactors, and motor drives. The NI-9351 is an analog input and digital I/O Functional Safety Module capable of SIL 3 certification according to IEC 61508. You can use the Functional Safety Editor to program the safety logic solver, which resides in the module. The module features diagnostics for monitoring the status of hardware and the integrity of the connections.