Transmit a Contact Closure Over a Single Fiber

Industrial Media Converters - Contact Closure

This Contact Closure Fiber Link system provides transmission of the contact closure signal over one optical fiber. Applications include alarm event triggering, building automation, environmental control systems, fire & alarm systems, gate control, traffic signal control equipment, and more.

This contact closure system is designed to operate over an extreme temperature range, providing reliability in non-temperature controlled environments. Accepts a wide power input rage of 12 through 48 volts DC allowing for flexibility in installation.


  • Convenient LED status indicators
  • Available with ST connectors
  • Singlemode and multimode options available
  • Input will sense a dry contact closure
  • Output relay is rated to support to 60 Watts
  • Can be powered by 12-48VDC
  • Pluggable terminal blocks
  • Alarm contact for status monitoring
  • Wide operating temp -40°F to +158°F (-40°C to +70°C)
  • Standard T35 DIN rail or wall mountable
  • Limited Lifetime Warranty
  • Made in USA

Multimode: 850nm
Singlemode: 1310nm

Fiber Type/Distance:
Multimode (62.5/125µm, 50/125µm): 1.2 miles (2km)
Singlemode (9/125µm): 9 miles (15km)
Singlemode Long Haul: 29 mi. (48 km), min. required loss *-8dB

*Note: Distances equated using industry standard fiber and connector attenuation of 3dB/Km. Fiber condition, splices and connectors may affect actual range.

Fiber Connector Type:

Steel and Aluminum Alloy, Powder coated

Mounting Style:
Standard DIN rail (TS-35) or wall mount

H4.93” x W1.2” x D3.5” (100mm x 31mm x 89mm)
Not including connectors, Din Clip, or Wall Mount Ears


Operating Temperature:
-40˚F to +158˚F (-40˚C to +70˚C)

General Information
Contact Closure System Application
Contact Closure System Application


Lead Time: 1 to 2 Weeks*

For product questions, volume pricing and/or delivery outside of the US and Canada, please contact sales.


Contact Closure

Product configurationTransmitter/ReceiverModeConnectorDistanceFibersPart numberPrice
Transmitter, Multimode, ST, 2km/1.2 miles, Single FiberTransmitterMultimodeST2km/1.2 milesSingle Fiber1CD-03-1$260.00
Receiver, Multimode, ST, 2km/1.2 miles, Single FiberReceiverMultimodeST2km/1.2 milesSingle Fiber1CD-04-1$260.00
Transmitter, Singlemode, ST, 15km/9mi, Single FiberTransmitterSinglemodeST15km/9 milesSingle Fiber1CD-20-1$360.00
Transmitter, Singlemode, ST, 48km/29mi, Single FiberTransmitterSinglemodeST48km/29 milesSingle Fiber1CD-21-1$460.00
Receiver, Singlemode, ST, 15km/9mi & 48km/29mi Single FiberReceiverSinglemodeST15km/9 miles & 48km/29 milesSingle Fiber1CD-22-1$360.00
  • A complete system requires a Transmitter and a Receiver
  • Singlemode receiver is compatible with all singlemode transmitters
  • When a fiber splitter is used, multiple receivers can be paired with one transmitter

*Lead times are estimates and may vary. You will be contacted within 1 business day to go over the details of your order. If you require a specific date, let us know!
*Days = Business Days

WarningWarning: This product can expose you to chemicals including arsenic, which is known to the State of California to cause cancer. For more information, go to

RLH Industries - Fiber Optic Link
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