Versitron F270XAD, F271XAD Technical Manual

F270XAD

Fiber-Optic

Telephone Modem with RS485 Data

Technical Manual

Revision A

© January 2014

VERSITRON, Inc.

83 Albe Drive / Suite C

Newark, DE 19702

www.versitron.com

Safeguarding Communications Since 1958

PROPRIETARY DATA

All data in this manual is proprietary and may not be disclosed,
used or duplicated, for procurement or manufacturing purposes,

without prior written permission by VERSITRON.

VERSITRON LIFETIME WARRANTY

All VERSITRON products are covered by a Lifetime Warranty against defects in materials and workmanship. This
coverage is applicable to the original purchaser and is not transferable.

We repair, or at our option, replace parts/products that, during normal usage and operation, are proven to be defective
during the time you own the products, provided that said products and parts are still manufactured and/or available. Such
repair/replacement is subsequent to receipt of your product at our facility and our diagnostic evaluation and review of the
unit. Advance replacements are not provided as part of the warranty coverage.

This warranty does not cover damage to products caused by misuse, mishandling, power surges, accident, improper
installation, neglect, alteration, improper maintenance, or other causes which are not normal and customary applications of
the products and for which they were not intended. No other warranty is expressed or implied, and VERSITRON is not
liable for direct, indirect, incidental or consequential damages or losses.

In the unlikely event a warranty issue should arise, simply contact us at 302-894-0699 or 1-800-537-2296 or via e-mail to

[e-mail] and obtain a Return Material Authorization (RMA) number. Reference this number on the outside

of the shipping container and return the unit (shipping charges prepaid) to us for diagnostic review and repair/replacement
as determined solely by VERSITRON. We pay the shipping charges to return the repaired unit or a replacement unit to you.

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1.1 INTRODUCTION

This manual provides general and detailed information on the installation and operation of
the Model F270XAD Fiber-Optic Telephone Modem. Section 1 provides a general description of
the equipment. Section 2 provides installation instructions. Section 3 provides operating
instructions. Section 4 provides the theory of operation. Section 5 provides maintenance and
troubleshooting information. Illustrations 1 and 2 provide an overall view of the telephone
modems.

1 DESCRIPTION OF EQUIPMENT

Illustration 1: Front View, F270XAD

Illustration 2: Rear View, F270XAD

1.2 DESCRIPTION OF EQUIPMENT

1.2.1 Functional Characteristics

The Model F270XAD Telephone Modem is a modem for exchange (PBX or direct dial
service from a telephone company) connected telephone lines. These units are designed to be used
with Model F271XAD, which supply a subscriber (telephone handset) interface. When
configured in this way, the modems provide a fiber optic link for regular, 2-wire analog
telephones. The main characteristics of the Model F270XAD are:

 Transparent extension of telephone lines.
 SFP Based optics.
 Supports RS-485/RS-422 full duplex data up to 64kbps.
 Supports data up to 14.4kbps via dial-up modem or facsimile.

Model F270XAD and F271XAD modem pairs use SFP optic modules to achieve transmit
distances of up to 20km over a single pair of fiber-optic cable. Alternatively, these telephone

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modems can be used in a VMX20 Versimux II chassis, which can multiplex up to 19 telephone
modems on a single pair of fiber-optic cables.

1.2.2 Audio Transmission Characteristics

The F270XAD accepts a telephone audio signal on its RJ11 connector from the exchange,
and digitizes it with an analog-to-digital converter. Each of the digital samples is then encoded
and applied to the SFP for transmission over the fiber-optic cable.

The remote F271XAD unit decodes the signal from the SFP module and applies it to a
digital-to-analog converter to recover the analog audio. The converse occurs in the other
direction for the F270XAD.

The telephone modem transmits analog signals of 300 to 3400Hz.

1.2.3 RS-485 Transmission Characteristics

The F270XAD accepts balanced RS-485/RS-422 data on the RJ45 connector for
transmission across the fiber-optic line. Data speeds of up to 64kbps are achievable. This
interface is full duplex only.

1.2.4 Physical Characteristics

The telephone modems measure 7.0" wide x 0.84" high x 11.6" deep (17.8 x 2.1 x 28.9
cm) and are designed to be mounted in a variety of VERSITRON enclosures and chassis (see
Table 1 for dimensions of enclosures and chassis). "Desktop" option is a single-card enclosure.
Rack-mount options include a 2-Slot and 20-Slot 19” standard rack-mountable chassis. For
either desktop enclosure or 2-Slot rack-mount chassis, each F270XAD unit requires a wall
transformer, VERSITRON Model PSAC08 (US) or PSAC09 (European), providing 12 VDC,

1.0A. The one-pin power connector for electrical input is on the back of the card. There is a
RJ11 jack for the telephone line on the front of the card. There is an SFP module slot on the back
of the card for the SFP fiber-optic interface. For HF-20A chassis installations, power is provided
by VERSITRON Model AC300WR Power Supply / System Monitor, through the twelve pin
connector (P1). For Versimux II installations, power is provided to the VMX20 chassis by
VERSITRON Model AC300WR Power Supply / System Monitor, through the twelve pin
connector, and the link connection is provided by the backplane connector (J5). In Versimux II
installations the SFP module will be deactivated, and link communications will occur over the
backplane connector J5. Therefore, the SFP need not be populated in Versimux II installations.
Both F270XAD and F271XAD models have eight indicator LEDs as described in Table 2.

Table 1: Dimensions of Enclosures and Chassis

Model #

(Part #)

HF-1

(19052)

HF-2SS

(19629)

HF-20A

(32406)

VMX20

(32458)

*¹ Note: US Model – PSAC08; European Model – PSAC09
*² Note: One Power Supply per Modem required.

Dimensions Description Power Supply Required*¹

1.3" H x 7.1" W x 11.6" D
(3.3 x 18.0 x 29.5 cm)

1.7" H x 19.0" W x 13.8" D
(4.3 x 48.0 x 35.0 cm)

7.0" H x 19.0" W x 11.6" D

(17.8 x 48.0 x 29.5 cm)

7.0" H x 19.0" W x 11.6" D

(17.8 x 48.0 x 29.5 cm)

Single Card Desktop Enclosure

Dual Card Rack-Mount Chassis*²

(Side-by-Side)

20 Card Rack-Mount Chassis

20 Card Rack-Mount Chassis

(19 Multiplexed Slots)

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PSAC08 PSAC09

(LTWPD1210PLX) (LTWPD1210EPL)

PSAC08 PSAC09

(LTWPD1210PLX) (LTWPD1210EPL)

AC300WR

(32410)

AC300WR

(32410)