MTL5501-SR - Fail-safe Switch/Proximity detector interface

Digital Input modules
The Digital Input (DI) module range offers solid state or relay output switches in a safe area that respond to input switches located in a hazardous area. Single or multiple channel (2 or 4) options are available, as well as Line-Fault Detection (LFD).
Modules with LFD can recognise open or short circuit conditions on the input wires going to the field sensors, and some DI modules have the facility to reverse the effect of the input on the output i.e. phase reversal.
These options are chosen with switches located on the edge of the module on the hazardous area terminal side. In some applications it may be easier to set these switches before fitting the module to the DIN-rail.

MTL5501-SR - Fail-safe Switch/Proximity detector interface
Single channel, fail-safe module with line-fault detection
The MTL5501-SR enables a fail-safe switch/proximity detector located in the hazardous area to control an isolated fail-safe electronic output. It provides line-fault detection (LFD) alarm contacts and is designed for use with approved fail-safe sensors in loops that require operation up to SIL3 according to the functional safety standard IEC 61508.
Note: For reliable, long-term operation the load on the LFD switching relay should be not less than 50mW, e.g. 10mA at 5V DC.