RAD FOM-5S, FOM-6S Synchronous Fiber Optic Modems  

Call us for Pre-sales and discount pricing

  301-924-7400 Support

RAD FOM-5S, FOM-6S Synchronous Fiber Optic Modems 

  • The FOM-5S and FOM-6S, Fiber Optic Modems, are used for local data distribution, connecting full or half duplex synchronous computers and terminals. A pair of modems ensures integrity of data transmission over fiber optic cable at distances up to 3 km (2 miles).
  • FOM-5S is a smaller version of FOM-6S, with all the same features. FOM-5S is 75 mm (3.0 in) by 18 mm (0.7 in); FOM-6S is 108 mm (4.3 in) by 24 mm (0.9 in).
    FOM-6S is normally provided in a plastic enclosure. It can optionally be supplied in a metal case to reduce radiated emission (see Ordering).
  • A LED indicator indicates carrier detection on FOM-5S and FOM-6S models that are enclosed in a plastic case.
  • Transmit timing can be provided by three alternative sources:
    • Internal oscillator
    • External clock from the DTE via pin 24
    • Loopback clock derived from the receive signal.
  • The carrier can be strapped for either continuous or switched operation, controlled by the RTS signal for transfer of a control signal end-to-end.
  • The delay between Request to Send and Clear to Send can be set for either 7 or 53 msec.
  • Innovative circuitry allows FOM-5S and FOM-6S to operate without connection to the mains supply, by using ultra low power from the data and control signals.
  • FOM-5S and FOM-6S incorporate all the advantages of a fiber optic system, providing:
    • Lower attenuation than with copper wire
    • EMI/RFI and noise immunity, saving the cost of expensive and heavy shielding and complex error checking routines
    • Almost absolute security and reduction in the cost of data encryption
    • Negligible power radiation from the fiber makes eavesdropping virtually impossible
    • Safety and electrical isolation: no spark hazard and no ground-loop noise problems.

    Note: Attenuation is unrelated to frequency.


  • Synchronous transmission up to 19.2 kbps
  • Transmission range up to 3 km (2 miles) regardless of data rate
  • Full or half duplex
  • Transfers one control signal end-to-end
  • No external power required
  • Plugs directly into the V.24/RS-232-C terminal connector
  • Compact, lightweight, easy to install
  • LED indicator for carrier detect


Synchronous Fiber Optic Modem


Synchronous Fiber Optic Modem

* Specify:
F for female 25-pin connector
M for male 25-pin connector
# Specify:
W for metal enclosure (FOM-6S only)
Default is plastic enclosure
+ Specify:
SMA for SMA type optical connectors
ST for ST type optical connectors
FC for FC type optical connectors
SC for SC type optical connectors (FOM-6S only)






A pair of FOM-5S or FOM-6S modems ensures secure
data transmission over fiber optic cable at distances up to 3 km (2 miles).


RAD Products

For discount pricing on RAD Data Communications  
email us at sales@data-connect.com
or call 301-924-7400