Phoenix Contact 1487644 This safety relay offers a range of multi-functional capabilities, featuring up to SIL level 3 and Cat 4 certification for enhanced reliability. It operates with two sensor circuits, allowing for one- or two-channel operation in automatic or manual modes, with monitored start functionality. The device includes two enabling current paths and provides two signal outputs, while its power supply is 24V DC US, and it features a plug-in push-in terminal block for easy installation.