RS4 relays feature Normally Open (NO) contacts guaranteed on opening with the highest safety level, SIL4, and Normally Close (NC) contacts. These contacts are weld no transfer, compliant with EN 61810-3 Type A (forced guided contacts). They are available in several command voltages, mounting interfaces and NO and NC contacts configurations.

Certified EN 50155, RS4 vital relays are suited for train on-board applications.

For trackside application, like signalling project, some RS4 relays feature two voltage inputs to accommodate the impedance of the connection between the command of the RS4 relay and the RS4 relay: 0 to 18Ω and 18 to 45Ω.

Finally, the RS4 relay 202 features 2 NO contacts (guaranteed on opening in SIL4) and 2 NC contacts. It is supplied to be mounted on DIN rail and is also available in 3U card format. In this format, two RS4 202 relays are included in one 3U card.