Bidirectional contact repeater ensures reliable long-distance signal delivery

Remote monitoring specialist Omniflex has launched the Omniterm FCX, a fibre optic switch contact signal repeater unit that transmits a switch contact status signal bidirectionally up to 20km. 

The first with a safety integrity level (SIL) 2 rating, the FCX will reassure system designers that they can build it into safety-critical systems. The unit uses fail-safe 1oo2 architecture and is ideal for the controlled, emergency shutdown of electrical substations and other safety-critical applications. 

The transceiver is compatible with either 850 nm multi-mode or 1310 nm single-mode fibre optic cabling; the latter can send switch contact signals up to 20 km of range. The FCX is powered from a 10-30 Vdc power supply and the device can operate in a range of 0-60 degrees Celsius.

“Getting switch contact signals point-to-point can be a matter of life and death,” explained David Celine, managing director of Omniflex. “When an operator hits an emergency stop button, they need to be confident that the system will shut down as designed. If someone is in danger at an industrial power station, the risk of signal failure has to be mitigated to an acceptable level. 

“This FCX is also a bidirectional transceiver, so it combines the transmission and reception capabilities into one device, eliminating the need for separate modules. One module is placed at either end of a duplex fibre optic link and when the contact on the first is closed, the other module is energised replicating the contact signal.”

The FCX can also figure in mining and materials handling and nuclear radiological safety warning signals and monitoring functions. The SIL-2 rating is a mark of trust for system designers that the risk associated with transmitting switch contact signals over long distances can be limited to appropriate levels.