F282XA

FOM II Series

Fiber Optic Modem

Technical Manual

RS-530 / MIL-STD-188-114

See Technical Data Sheet

Download Manual PDF

www.versitron.com

September 2001

Copyright  September 2001

VERSITRON, Inc.

83 Albe Drive / Suite C

Newark, DE 19702

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.

1. You call VERSITRON at 302-894-0699 or 800-537-2296 and obtain a Return Maintenance Authorization (RMA) number. Please reference your RMA number on the outside of the shipment box.

2. Shipping charges are pre-paid.

No other warranty is expressed or implied and we are not liable for consequential damages. For repairs outside of the warranty period, the same procedure must be followed.

TABLE OF CONTENTS

SECTION 1:  DESCRIPTION OF EQUIPMENT

1.1 INTRODUCTION
1.2 DESCRIPTION OF EQUIPMENT
1.2.1 Functional Characteristics
1.2.2 Physical Characteristics
1.3 SPECIFICATIONS

SECTION 2 INSTALLATION

2.1 GENERAL
2.2 SITE SELECTION AND MOUNTING\
2.3 POWER REQUIREMENTS
2.4 SWITCH SETTINGS
2.5 TIMING MODE
2.5.1 Source Timing
2.5.2 Terminal Timing
2.6 LOOPBACK
2.6.1 Fiber/Copper Loopback
2.7 INITIAL CHECKOUT PROCEDURE

SECTION 3:  OPERATION

3.1 INTRODUCTION
3.2 STATUS INDICATORS/AUDIBLE ALARM
3.3 Operating Controls

SECTION 4:  THEORY OF OPERATION

4.1 INTRODUCTION

SECTION 5:  MAINTENANCE AND TROUBLESHOOTING

5.1 INTRODUCTION
5.2 FAULT ISOLATION

List of ILLUSTRATIONS

1.  OVERALL VIEW, F282XA MODEM
2.  INTERFACE EXTENDER CONFIGURATION
3.  MODEM LINK CONFIGURATION
4.  MULTIPLEXER CONFIGURATION
5.  SWITCH SETTINGS

List of TABLES

1.  ENCLOSURES / CHASSIS
2.  TERMINAL AND SOURCE TIMING SWITCH SETTINGS
3.  MODEL F282XA SWITCH SETTINGS
4.  NON-OPERATIONAL INDICATORS

SECTION 1
DESCRIPTION OF EQUIPMENT

1.1    INTRODUCTION

This manual provides information on the installation and operation of the Model F282xA FOM II Series Fiber Optic Modem.  Section 1 contains a general description of the equipment.  Section 2 contains installation instructions.  Section 3 contains operating instructions.  Section 4 provides the theory of operation.  Section 5 contains maintenance and troubleshooting information.  Figure 1 is an overall view of the F282xA.

1.2    DESCRIPTION OF EQUIPMENT

Functional Characteristics

F282xA modems are designed to provide fiber optic links as interface extenders (Figure 2), modem links (Figure 3) or four channel multiplexers (Figure 4) for synchronous, asynchronous or isochronous data.  Units are DTE/DCE switch selectable. F282xA Modems use fiber optic cable up to 2km (1.25mi/6,600ft) with multimode 850nm optics, up to 8km (5mi/26,400ft) with multimode 1300nm optics, or 14km (8.7mi/46,000ft) with single mode 1300nm optics.  The link is fully transparent in both directions providing full-duplex, half-duplex, or simplex data transmission from 20 Bps to 300 Kbps with terminal timing or 20 Bps to 150 Kbps with source timing.  The fiber optic circuit consists of two units connected by fiber optic cable and has data rates and electrical signal characteristics that conform to EIA RS-530 and MIL-STD-188-114 standards.   This is accomplished by multiplexing the control signals along with clock and data signals and transmitting the combined signal to the remote unit.  At the remote end the combined signal is demultiplexed and applied to the interface.

Physical Characteristics

The   F282xA circuit card measures 7 x .9 x 11.8in. (WxHxL) and is designed to be mounted in VERSITRON enclosures or chassis (Table 1).  Four housing options are available.  HF-1 or HF-2 enclosures are available for single or dual card standalone applications.  HF-2SS or HF-20 chassis are available for 2-slot or 20-slot 19” rack mount applications.  Each modem installed in an HF-1, HF-2 or HF-2SS requires an AC/DC power adapter.  Each modem installed in an HF-20 chassis is powered by the AC150W power supply.  Two AC150W power supplies are recommended for redundancy.  The F282xA has seven indicators:  power (PWR), alarm (ALM), transmit data (TXD), receive data (RXD), transmit clock (TXC), receive clock (RXC) and loopback (LB).

FIGURE 1.  OVERALL VIEW, F282xA MODEMS

FIGURE 2.  INTERFACE EXTENDER CONFIGURATION

FIGURE 3.  MODEM LINK CONFIGURATION

FIGURE 4.  MULTIPLEXER CONFIGURATION

      *¹ Note:  US Model - PSAC08; European Model - PSAC09
      *² Note:  One Power Adapter per Modem is required.

TABLE 1.  ENCLOSURE / CHASSIS

ENCLOSURE / CHASSIS SAMPLE PHOTOS

1.3    SPECIFICATIONS

General Specifications:

Electrical Interface:

Fiber Optic Interface:

*Note:    Multimode tests were performed on 62.5/125 M fiber optic cable.

                      Single Mode tests were performed on 9/125 M fiber optic cable.

Major Features:

SECTION 2
INSTALLATION

2.1    GENERAL

 This section contains information on the installation and initial checkout of the F282xA FOM II Series RS-530 Modems.  Paragraph 2.2 contains general information on site selection and rack mounting.  Paragraphs 2.3 and 2.4 provide instructions for connecting Model F282xA Modems to your system and selecting the different options.  Paragraph 2.5 contains initial checkout procedures.

2.2    SITE SELECTION AND MOUNTING

The F282xA is designed to connect to the serial port (DB25 Male) of the terminal equipment with a cable (customer supplied).  The F282xA is designed to be mounted in a single-card or dual-card standalone enclosure or may be rack mounted in a 2-slot or 20-slot chassis.  (See Table 1 for Enclosure and Chassis dimensions).

2.3    POWER REQUIREMENTS

 The F282xA is designed to operate from an AC power adapter or a DC power source with a DC voltage of +12 VDC.  Before inserting the power adapter into an AC power source, the plug should be connected to the modem.  No special tools are required.          DC power may be used instead of the power adapter if available.  This requires a 2.5 mm socket with the positive voltage on the center and the common on the concentric using +12 VDC at 1A.

2.4    SWITCH SETTINGS

There are a number of switches on the Model F282xA Modem used to select between DTE/DCE operation and Terminal/Source timing selection.  Figure 5 shows the physical location of all of the switches, labeled SW1 through SW12.  With the exception of the loopback switch (SW1), which is on the front panel of the modem card, all of the switches should be set to the desired position prior to applying power to the modem, and then left in those positions unless the overall link characteristics change.

Switch 3 (SW3), located between the optics and the XILINX CPLD Complex programmable Logic Device chip U3, contains 8 ON-OFF switch positions.  The first two positions determine the interface standard that is expected as an input.  For SW3, Position 2 is set to ON for DCE operation, and OFF for DTE operation.  Positions 1 is set to OFF for DCE operation, and ON for DTE operation.

 The settings for SW12 should only be used on the modem which is configured for DTE configuration.  This switch is used to set the Terminal or Source timing operation for a DTE modem.  Both positions on this switch should be OFF for Teminal timing, and ON for Source timing.  SW12 should always be set to OFF position for a modem which is configured for DCE settings.  These settings are listed in Table 2.

FIGURE 5.  SWITCH SETTINGS

TABLE 2.  TERMINAL/SOURCE TIMING SWITCH SETTINGS

TABLE 3.  SWITCH SETTINGS

2.5    TIMING MODE

The F282xA Modems can operate in two different timing modes:  Source Timing and Terminal Timing.  All timing modes are application specific and can be configured using Switch 12, Position 1 and 2 as listed in Table 2.  As shown in Figure 5, Switch 12 (SW12) is located to the left of the CPLD U3 and above crystal Y2.  The following sections describe the operation and associated required switch settings for each mode.

2.5.1 Source Timing

A realignment circuit is needed in the Source (external) Timing configuration to account for the inherent delays and jitter introduced by noise and asynchronous sampling at all frequencies.  The realignment circuit is only used on the DTE units.  A clock detection circuit checks for a clock signal on input pins 12 and 15 of the DB25 interface.  If there are no clock signals on pins 12 and 15, no realignment takes place and data is output from the unit as it was received from the fiber optic input.  If there are clock signals present, the realignment circuit processes the data signal recovered from the fiber optic receiver before it is output onto pins 2 and 14.  In Source Timing mode, the F282xA Modem supports transmitted and received data, transmitted and received clocks, and eight control signals.  The unit shall transmit and receive balanced signals at a data rate between 20Bps and 150 Kbps with a bit error rate of 1x10^-9.  Refer to Table 2 for switch settings.

2.5.2 Terminal Timing

The Terminal (external) Timing mode is the basic mode of operation for the Model F282xA  Modems.  There is no circuit needed for data realignment.  In Terminal Timing mode, the F282xA supports transmitted and received data, transmitted and received clocks, and eight control signals.  Balanced signals, at a data rate from 20 Bps to 150 Kbps, are processed transparently by the Modem, with a bit error rate of 1x10M^-9.  Refer to Table 2 for switch settings.

2.6    LOOPBACK

The Model F282xA has one loopback feature.  This feature allows the user to test the copper circuitry of the unit under test.

2.6.1 Fiber / Copper Loopback

The loopback feature of the Model F282xA allows the user to test the copper circuitry of the unit under test.  This test feature is controlled by the front-panel switch (SW1).  When SW1 is ON, the multiplexer bit goes high and the loopback test feature is enabled.  The copper signal enters the board through the interface circuitry to the multiplexer circuit.  The signals are multiplexed, demultiplexed and transmitted back to the test unit.  This is true for all data, clock, and control signals.  When SW1 is OFF, the multiplexer control bit goes low, and the unit functions normally.  (The fiber optic circuitry may be tested by connecting a fiber optic patch cable between the transmit and receive optics of the modem under test.)

2.7    INITIAL CHECKOUT PROCEDURE

The Model F282xA FOM II Series products contain no power on/off switch.  Once the unit is properly installed and power is applied it may be considered fully operational.  The power indicator should remain on as long as power is supplied to the unit

Before beginning system operation the following items should be checked to verify proper installation:

1. Verify that the power plug is seated fully into the modem or the modem is seated firmly in the

                  rack-mount enclosure.
      2.   Verify that the fiber optic cable is crossed transmit to receive from unit one to unit two.

1. Verify that the alarm LED goes out when the signal is applied to the optical receiver of the

                  F282xA.
4.   Verify the switch settings for the circuit configuration (i.e. Source/Terminal timing).

If a malfunction is detected during the initial checkout procedure, refer to Chapter 5 for information on isolating the malfunction in the unit.

SECTION 3
OPERATION

3.1    INTRODUCTION

This chapter contains a description of the operating controls and indicators associated with the Model F282xA FOM II Series modems.  Since the Model F282xA is designed for continuous and uninterrupted operation, there are no operating requirements.  Once the Model F282xA is powered up it should remain in service as long as required.

3.2    STATUS INDICATORS/AUDIBLE ALARM

There are seven indicators on the F282xA: power (PWR), alarm (ALM), transmit data (TXD), receive data (RXD), transmit clock (TXC), receive clock (RXC), and Loopback (LOOP).  No audible alarm is available.

3.3    Operating Controls

The only operating controls associated with the F282xA Modems are those used to select between DTE/DCE, Source/Terminal timing selection, and the loopback functions.  These selections are normally made only at the time of installation.  Further changes are not required unless the system requirements change.

SECTION 4
THEORY OF OPERATION

4.1    INTRODUCTION

Basic operation of the Model F282xA is similar to a four-channel, full duplex multiplexer.  The first channel is used for data.  The next two channels are used for transmit and receive clock while the fourth multiplexer channel is used for aggregated control signals.  This technique provides full transparency for the link, even when both clocks originate at the modem.  The modem supplies both transmit and receive clocks to the Model F282xA, which are transmitted through the link and applied directly to the terminal.

The interface control signals are processed in a similar manner  The Request to Send signal from the terminal is transmitted through the link and applied to the modem.  When the modem responds with Clear to Send, it will be transmitted through the link and applied to the terminal.  With this technique, the terminal will see the RTS/CTS delay established by the modem.

If a fully transparent synchronous link is not required, the clock and control paths may be used as additional asynchronous data paths.  The transmit and receive clock inputs will handle data rates from 20 Bps to 300 Kbps asynchronously;  the control paths will handle data rates up to 9.6 Kbps.

SECTION 5
MAINTENANCE AND TROUBLESHOOTING

5.1    INTRODUCTION

This chapter contains general information designed to isolate a malfunction in the Model F282xA to a replaceable unit.  These units are not equipped with redundancy.  Therefore, a failure in one of these units would interrupt service.

5.2    FAULT ISOLATION

         The  steps in Table 4 should be taken to check a non-operating modem.

                        TABLE 4.  NON-OPERATIONAL INDICATORS

If you are still experiencing problems, please contact VERSITRON customer service for assistance at 302-894-0699 or 800-537-2296.

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