4-channel isolated barrier, 24 V DC supply (bus powered), Dry contact or NAMUR inputs, 4 passive transistor outputs, Line fault detection (LFD), Up to SIL 2 acc. to IEC/EN 61508, Housing width: 18 mm, Number of channels: 4-channel, Safety Integrity Level (SIL): SIL 2, Rated voltage: 19 ... 30 V DC bus powered via Termination Board, Field device: NAMUR sensor, Field device [2]: volt-free contact, Line fault detection, Type: 4 x Transistor (passive), Fault indication output