The Context Plus XP95 input/output unit provides two voltage-free, single pole, change-over relay outputs, a single monitored switch input and an unmonitored, non-polarised opto-coupled input.
Compliant with EN54-17 & 18 (2005), the Input/Output Unit supervises one or more normally-open switches connected to a single pair of cables.
It is set to return an analogue value of 4 in the event of an open or short-circuit fault and 16 during normal operation. The status of the inputs is reported by means of two input bits. The change-over contacts are operated by an output bit.
The Input/Output unit is fitted with a bi-directional short-circuit isolator and will be unaffected by loop short-circuits on either loop input or output.