ComNet FDC8: Contact Closure Transmission, 8-Channel

ComNet FDC8: Contact Closure Transmission, 8-Channel

Product Code: CN-FDC8


The ComNet FDC8 Series contact closure transmitter and receiver provides transmission of up to eight independent contact closures over one RS232 link or optical fibre. Microprocessor-based logic sends the contact information in packets that are ordered and encoded, ensuring extremely robust transmission. Packets that are garbled, packets out of sequence, and transmission bit errors will not cause random changes of state on the contact relays. Also, the mechanical latching relays maintain their state even when the unit loses power. Each module incorporates power and individual status indicating LEDs for monitoring confirmation of contact closure of each of the eight channels. Packaged in the exclusive ComNet ComFit housing, these units may be either wall or rack-mounted, or may be DIN-rail mounted by the addition of ComNet model CN-DINBKT1 or CN-DINBKT4 adapter plate.

Product Options

Please add suffix ‘/C’ for Conformally Coated Circuit Boards to extend to condensation conditions – please contact us for pricing and delivery

Mounting: DIN-rail mounting adapter plate kit with mounting hardware – please order model CN-DINBKT1 or CN-DINBKT4

  • Transmits up to eight contact closures over one RS232 link, or one optical fiber
  • Eight channel Point-to-Point transmission architecture
  • Indicating LEDs for monitoring power and contact channels
  • Eight SPST latching relays (with individual indicators)
  • Tested and certified by an independent laboratory for full compliance with the environmental requirements (ambient operating temperature, mechanical shock, vibration, humidity with condensation, high-line/low-line voltage conditions and transient voltage protection) of NEMA TS -1/TS -2 and the Caltrans Specification for Traffic Signal Control Equipment
  • Microprocessor-based logic and latching relays in receiver unit eliminate random contact closure status in the event of loss of link or loss of prime operating power.
  • Relay contact rating: 30Vdc, 1A, normally open
  • Automatic resettable solid-state current limiters
  • Hot-swappable rack modules
  • Interchangeable between stand-alone or rack mount use – ComFit
  • ComNet Lifetime Warranty


DC plug-in power supply, 90-264 Vac, 50/60 Hz included

† Optical transmission distance is limited to optical loss of the fibre and any additional loss introduced by connectors, splices and patch panels. Distance can also be limited by fibre bandwidth.

‡ For 50/125?m fiber, subtract 4 dB from the optical power budget


Part CodeDescriptionNo. of FibresFibre TypeOptical Power BudgetMax Distance †No. of Rack Slots
CN-FDC8TM18-Channel Contact Closure Transmitter1Multimode - 62.5/125?m or 50/125?m ‡ 16dB16km1
CN-FDC8RM1 8-Channel Contact Closure Receiver1Multimode - 62.5/125?m or 50/125?m ‡16dB16km1
CN-FDC8TS18-Channel Contact Closure Transmitter1Singlemode - 9/125?m 23dB 69km1
CN-FDC8RS18-Channel Contact Closure Receiver1Singlemode - 9/125?m23dB69km1
CN-FDC8T232 8-Channel Contact Mapping Transmitter, RS232 Data Channel----1
CN-FDC8R2328 Channel Contact Mapping Receiver, RS232 Data Channel, Latching Contacts----1

How to order:

Simply send us a message using the quote form or contact our team direct via the details below!