Your Copper to Fiber Connection

Call Us Email Us

2-Wire Analog Telephone AND/OR RS-485 / RS-422 Data

Telephone or TeleData Modems | Model F27xxA, Model F27xxAD

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


VERSITRON FOM II Series TeleData Modems are used to extend a telephone and/or data (RS-485 or RS-422) link on duplex fiber optic cable or 2 wire twisted pair cable. The F270xAD or F270xA functions as the exchange side device while the F271xAD or F271xA functions as the subscriber side device. For intercom or ring-down applications, the F271xAD or F271xA is used at each end of the connection. An RJ11 provides the copper interface for the analog voice input or dial-up at 14.4Kbps. An RJ45 provides the copper interface for RS-485/RS-422. LC connectors are standard for the f.o. interface. Several different configurations are offered to accommodate a wide variety of applications with full transparency.

These products are available with 1310nm multimode optics for distances up to 2km (1.25 mi/ 6,600 ft), or with 1310nm singlemode optics for distances up to 20km (12.43 mi / 65,630 ft). If the copper interface is utilized then up to 1 km (.625 mi/ 3,300 ft.) two wire twisted pair cable may be used to complete the circuit. LC connectors are standard. Housing options include either a single card standalone enclosure, or a 2-slot or 20-slot 19 inch rackmount chassis. The 20-slot chassis is powered by the AC300WR redundant power supply and system monitor. Each device installed in either the single card enclosure or in the 2-slot chassis requires an AC to DC power adapter.

Click Here for 2 Wire Analog POTS Kits for 1,4,& 8 Channel Applications.

These products can be found in 3 unusual applications. The multimode analog F27xxA FOM II series are being used to help reduce energy costs by monitoring power usage in a manufacturing plant on the East Coast. These converters provide reliable data links that would otherwise be impossible in this EMI intense environment.

The F27xxAD and F27xxA devices are currently in use as communication devices to control a boring machine whose purpose is to tunnel through a mountain.

ATM machines at gas stations and convenience stores are employing the F27xxAD and F27xxA devices to ensure safe transmission of data on POTS lines over f.o. cable. Therefore, making sure that the equipment remains safe from lightning strike damage.


VERSITRON Models' F27xxAD and F27xxA digitizing process allows for complete transparency. This digitizing process also provides reliable optical isolation. Other features include:

  • Intercom or ring down application with two model F271xAD subscribers or F271xA subscribers
  • 1310nm multimode or 1310nm singlemode options
  • Line impedance option of 600 or 900
  • Multiplexes voice and data (RS-422 or RS-485) up to 64Kbps for copper or fiber transmission (Models F271xAD and F270xAD)
  • 14.4Kbps data rate over analog voice line for dial-up or fax

Annunciator lights are used as status indicators primarily for the voice link status. Their function is as follows:

PWR--Power on indication for normal operation

HOOK--Off-hook indication

RING--Ringing signal indication

LOOP--Loop current detect indication

RBAT--Reverse battery detect indication

ALM--Out of sync indication


The models F270xAD and F271xAD AND the F270xA and F271xA FOM II 2-wire analog TeleData and Telephone products are now compatible with the VERSITRON Versimux II  f.o. voice/data multiplexer. The 20-slot Versimux II platform supports copper to fiber conversions in 1-channel, 4-channel, and 8-channel configurations. In addition, the Versimux II  supports all standard serial data interfaces. Simultaneous voice AND data links can even be configured within the same chassis.

Check out the Versimux II.



83 Albe Drive - Suite C - Newark, DE 19702
Need Help? Call: 1-800-537-2296, or 302-894-0699 Fax: 302-894-0624
Copyright Versitron. All Rights Reserved.