OFP-4010:   Fibre Optic 2x2 Changeover Protection Switch.


      Automatic switching when optical level falls below a settable preset limit.
      External momentary Set/Reset control.
      No path change on power fail.
      Local or remote control.
      Front panel LED status indicators.
      Optional plug in SNMP monitoring and switching module.


User Manual  


The OFP-4010 is a magnetic latching 2x2 changeover optical switcher using a high performance optical relay and optical level detectors. It is suitable for switching optical signals being run over single mode optical cable.

The OFP-4010 is arranged as a changeover switch with two inputs and two outputs. The latching characteristic of the high performance optical relay allows momentary control and also provides for no change of path during power loss.

Changeover switching is done either automatically, locally or remotely. Optical detectors measure the optical power level and automatically switch the optical relay when signal strength falls below a dip switch selectable power level threshold set from -30 dBm to -5 dBm in 5dBm steps.

Local switching is possible using front panel push button switches. Remote switching is possible using external normally open or normally closed alarms.

The OFP-4010 is ideally suited to applications where a simple choice between two inputs or outputs is required and may be easily driven by detector circuits for automatic path selection.

Remote indication of tally and alarms are provided for integration into central alarm and monitoring systems.

An optional SNMP (Simple Network Management Protocol) plug-in module is available for remote monitoring and control when used in conjunction with IRT's frame fitted with SNMP capability.

The OFP-4010 is designed to fit IRT's 1RU and 4000 series 3RU Eurocard frames1 and may be used alongside any other of IRT's analogue or digital Eurocards.


Signal Path:
Signal Type
Various, Single Mode Optical.
Switching Characteristic
Magnetic latching 4 port changeover optical relay.
Operating Wavelength
1260nm to 1610nm.
Insertion Loss
2.5 dB across full range;
1.5 dB for 1260nm to 1360nm and 1510nm to 1610nm.
Cross talk
< -60 dB.
Switching Speed
< 10 ms.
Power Threshold
-30dBm to -5dBm in 5dB increments, selectable.

Auxiliary Data:
               Main In to Main Out
Connection between pin 1 (NC) and pin 3 (COM).
               Standby In to Main Out
Connection between pin 2 (NO) and pin 3 (COM).
               Main Optical fail
Pin 2 open circuit on Main fail.
               Standby Optical fail
Pin 1 open circuit on Stby fail.
Pin 3.

Remote Control:
Switch to open circuit or switch to ground, selectable.
(Main I/P to Standby O/P, Standby I/P to Main O/P)
Switch to open circuit or switch to ground, selectable.
(Main I/P to Main O/P, Standby I/P to Standby O/P)

SC/PC (standard).
3 pin Phoenix pluggable screw block.
3 pin Phoenix pluggable screw block.
3 pin Phoenix pluggable screw block.

Power Requirements:
28 Vac CT (14-0-14) or 16 Vdc.
Power consumption
1 VA.

Temperature range
0 - 50°C ambient.
Suitable for mounting in IRT 19" rack chassis with input, output and power connections on the rear panel.
Finish:             Front panel
Grey background, black lettering & red IRT logo.
                       Rear assembly
Detachable silk-screened PCB with direct mount connectors to Eurocard and external signals.
6 HP x 3 U x 220 mm IRT Eurocard.
Supplied accessories
Rear connector assembly with matching connectors for control, alarm and tally.
Optional accessories
SMU-4000 SNMP plug-in module for use with IRT frame fitted with SNMP "Agent".


Due to our policy of continuing development, these specifications are subject to change without notice.