Door, step and interlock control circuits combine safety signals with controller outputs, and in these circuits the contact state must be unambiguous even after a fault. The HL 3094N interface module with forcibly guided contacts multiplies the signal onto NO contacts, and the NC contact linked to them allows the output state to be monitored in the safety loop; spring-clamp terminals keep their contact force under vibration, and the datasheet declares a design to EN 50155.
For the boards of the vehicle's own door controllers and safety modules DOLD offers the OA 5621 and OA 5622 relays with forcibly guided contacts, with low height, low holding power and a wash-proof housing for wave soldering; DOLD lists railway technology among the applications in the datasheet.
Selection covers the coil voltage against the onboard battery, the contact arrangement and the contact material: the gold-plated version for small signal currents, AgSnO₂ for inductive loads. The safety function of the complete circuit is validated according to EN ISO 13849-2.
If an emergency stop button appears in the circuit, the safety circuit is closed by the UF 6925 module with outputs on forcibly guided contacts, Category 4 / PL e according to the datasheet.
