2 Wire Analog Telephone AND/OR RS-485, RS-422 Phone Modem


In typical analog telephone applications, these devices are used in pairs with the F270xAD or F270xA unit installed at the exchange side and the F271xAD or F271xA unit installed at the subscriber side.

2-Wire Telephone Fiber Optic Modem

Call for GSA Pricing
((1-800-537-2296) or (302-894-0699))


In typical analog telephone applications, these devices are used in pairs with the F270xAD or F270xA unit installed at the exchange side and the F271xAD or F271xA unit installed at the subscriber side. The units are linked together using multimode fiber or singlemode fiber as appropriate. Other configurations are possible, such as ring-down or intercom applications.

These serial data modems have 3 distinct features:

  • The phone portion of these products converts a standard loop start two-wire analog voice circuit to light signals for transmission over fiber optic cable.
  • The data portion of these products provides RS-485 or RS-422 data links over fiber. Maximum data rate is 64 Kbps. (F27xxAD Only)
  • The analog circuit supports data up to 14.4kbps via dial-up or fax.

As an added feature, the F27xxAD can do simultaneous teledata transmission. The F27xxA is for voice only.

These products are becoming more and more popular for use in residential "gated community" applications. These devices are especially beneficial where long distances are in play between the gate itself and the monitoring station.

2-Wire Telephone Fiber Optic Modem

IMPORTANT Product Update!

The models F270xAD and F271xAD FOM II TeleData modems AND the F270xA and F271xA analog voice only products are now compatible with the VERSITRON Versimux II fiber optic "voice and/ or data" multiplexer. The 20-slot Versimux II platform supports copper-to-fiber conversions in 1-channel, 4-channel, and 8-channel configurations for 2-wire voice only products. 

In addition, the Versimux II also supports all standard serial data interfaces. Simultaneous voice AND data links can even be configured within the same chassis.