F2238 / F2240 / F2245

FOM II Series

RS-530

High-Speed

Fiber Optic Modem

Technical Manual

June 2004

Copyright June 2004

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, Inc .

WARRANTY

All VERSITRON products purchased after January 2001 carry a limited lifetime warranty against defects in material and workmanship. Purchases made prior to January 2001 are warranted for a period of one year from date of delivery. VERSITRON reserves the right to repair or, at our option, replace parts which during normal usage prove to be defective during the warranty period provide that:

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 shipping 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 JUMPER SETTINGS

2.4.1 Polarity Straps

2.4.2 Jumpers For Input Impedance Selection

2.4.3 Jumpers For Transmit Clock Selection

2.4.4 Jumpers For Receive Clock Selection

2.4.5 Settings for Balanced/Unbalanced Outputs

2.5 OUTPUT CONNECTIONIS

2.6 LOOPBACK

2.7 INITIAL CHECKOUT PROCEDURE

SECTION 3: OPERATION

3.1 INTRODUCTION

3.2 STATUS INDICATORS

3.3 BIT RATE MONITOR

3.4 CLOCK SELECT OPTIONS

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

2. modem link configuration

3. modem jumper and test point locations

List of TABLES

1. ENCLOSURES / CHassis

2. JUMPER SETTINGS

3. ELECTRICAL (DB25) INTERFACE PINOUT

4. NON-OPERATIONAL INDICATORS

SECTION 1

DESCRIPTION OF EQUIPMENT

1.1 INTRODUCTION

This manual provides general and detailed information on the installation and operation of Model F22XX FOM II Series RS-530 High-Speed Fiber Optic Modems. 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 F22XX circuit card assembly.

* Note : Multimode tests performed @ 100 Kbps on 62.5/125 µM fiber optic cable.
Single mode tests performed @ 100 Kbps on 10/125 µM fiber optic cable.

1.2 DESCRIPTION OF EQUIPMENT

1.2.1 Functional Characteristics

1.2.2 Physical Characteristics

Model F22XX modems measure 7 x 1 x 11 in. WxHxL (17.8 x 2.5 x 27.9 cm). They are designed to be mounted in VERSITRON’s FOM II Series HF enclosures and chassis (see Table 1). Model HF-1 (single card) desktop enclosures are available for standalone applications. Standard 19" rack mountable options include models HF-2SS (2-slot) and HF-20A (20-slot) chassis. Each modem installed in models HF-1 or HF-2SS requires its own VAC to VDC power adapter. Each power adapter uses the one-pin connector on the back of the modem for power input. (Customer provided power may be supplied to the modem using the same one-pin connector.) When installed into the HF-20A chassis model AC300WR power supply is used to provide power to the chassis and to the modems. Power is provided from the AC300WR power supply to the HF-20A chassis via model HF-CA3 power interface cable where it is then distributed to any FOM II Series modem installed in the chassis. Power redundancy is included with the AC300WR power supply with two separate AC input cables provided for power input from separate VAC sources. The RS-530 copper interface is a female DB25 connector and is located on the back of the modem. The fiber optic interface, also located on the back of the modem, consists of two ST connectors (one transmit; one receive). Model F22XX Modems have five indicator LEDs: power on (PWR), loop indicator (LOOP), transmit data present (TX), receive data present (RX), and loopback mode indicator (LB).

FIGURE 1. OVERALL VIEW, F22XX MODEMS

FIGURE 2. F22XX MODEM LINK CONFIGURATION

* One Power Adapter per Modem is required when installed in these Models.

FIGURE 3. F22XX MODEM JUMPER AND TEST POINT LOCATIONS

2.4.2 Jumpers for Input Impedance Selection

Channel 1 (Transmit Data) and Channel 2 (Synchronous Transmit Clock or Asynchronous Data #2) will be set for high impedance when jumpers JP7 and JP9 are not inserted. If JP7 and JP9 are present, the input impedance is 100 ohm. The 100 ohm termination is not available on the DTR input.

2.4.3 Jumpers for Transmit Clock Selection

The transmitter operating mode is controlled by jumper JP1. For automatic, rate-dependent selection of transmitted synchronous clock and data, set JP1 = 3-4. To have the input data stream synchronized to the internal 10 MHz clock while being processed ("forced sync"), set JP1 = 1-2. For fixed over-sampling of asynchronous data ("forced async"), set JP1 = 5-6. On the circuit board, pins 1, 3, and 5 are tied together, so the jumper appears as follows:

1o----3o----5o
2o     4o      6o

2.4.4 Jumpers for Receive Clock Selection

For automatic mode (receiver tracking transmitter, full duplex operation) receive clock and data, set JP3 = 2-3 and JP13 = 1-2, 7-8. For forced synchronous mode (data clocked by internal 10 MHz clock), set JP3 = 2-3 and JP13 = 5-6, 7-8. For forced asynchronous mode, if the receiver is being used with no transmit clock, or for two asynchronous data channels, set JP3 = 1-2 and JP13 = 1-2, 7-8.

2.4.5 Settings for Balanced/Unbalanced Outputs

The conversion from Balanced to Unbalanced output data streams is accomplished using jumper JP11, which is a 24-pin jumper network. For MIL-STD-188-114 Balanced (RS-422 compatible) output, JP11 connects the following pins together: 2-23, 4-21, 6-19, 8-17, 10-15, and 12-13. When a change to MIL-STD-188-114 Unbalanced (RS-423 compatible) output is desired, JP11 must be removed, rotated 180 degrees, and reinserted so that the following pins are connected: 1-24, 3-22, 5-20, 7-18, 9-16, and 11-14.

2.5 Output Connections

The F22XX Modem uses a standard DB25 Female connector for the electrical signal interface. The pinout for this is given in Table 3.

TABLE 3. MODEL F22XX ELECTRICAL SIGNAL INTERFACE (DB25F) PINOUT

2.6 LOOPBACK

The F22XX Modem has a loopback mode to facilitate the testing of the unit in a system environment. When the Loopback switch on the front panel of the circuit card is in the ON position, the line encoder is routed directly to the line decoder, and the fiber optic receiver output is connected directly to the fiber optic transmitter input. This achieves a loopback of the transmit data to the receive data output, the transmit clock to the receive clock output, the DTR input to the DCD/DSR output, and the received optical input to the transmit optical output. Therefore the loopback mode tests virtually 100% of the Modem.

2.7 INITIAL CHECKOUT PROCEDURE

The F22XX Modem contains no power on/off switch. Once properly installed and powered, the unit is fully operational. The power indicator should remain on as long as power is supplied to the unit.

Before beginning system operation, to ensure proper installation, verify that:

1. The power plug is seated fully into the Modem or seated firmly in the rack-mount chassis.
2. The fiber optic cable is crossed transmit to receive from unit one to unit two and vice versa.
3. The LOOP LED illuminates when a link is established to the remote optical receiver of the F22XX. Note that the LOOP LED will illuminate regardless if there is data flowing to indicate a valid link between the two modems over fiber optic cable.
4. The jumper settings for the circuit configuration are correct (e.g. non-inverted/inverted signal polarity, clock selection, balanced/unbalanced outputs).

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 F22XX FOM II series Modems. Since the Model F22XX is designed for continuous and uninterrupted operation, there are no changes required during operation. Once powered up the Model F22XX should remain in service as long as required.

3.2 STATUS INDICATORS

3.3 BIT RATE MONITOR

3.4 CLOCK SELECT OPTIONS

The only controls with the Model F22XX FOM II Series Modems are those jumpers that configure the operation in one of three modes: Automatic, Forced Synchronous, and Forced Asynchronous. The Automatic mode is appropriate for use with full duplex data transmission. One of the two Forced modes should be used if the transmit and received sections of the circuit board are operated independently of each other. The jumper settings are described in Section 2.4 and selection is normally done at the time of installation. Further changes are not required unless the overall system requirements change.

SECTION 4

THEORY OF OPERATION

4.1 INTRODUCTION

Basic operation of the Model F22XX is similar to a two-channel, full duplex multiplexer. The first channel is used for high-speed synchronous data. The second channel is used for transmit clock, or for an asynchronous second data channel. Both channels may be used for low-speed (less than 100 Kbps), asynchronous operation.

The first of the three operating modes of the F22XX Modems permits data transparency. In the Automatic mode a data rate from 250 Bps to 10 Mbps is accepted and the data rate may be variable, as is sometimes seen in high-speed telemetry systems. An internal bit rate monitor circuit selects the source of the transmit clock. At clock rates of less than 100 Kbps, or when no external clock is present, an internal 10 MHz reference signal is utilized as the clock. This assures a sufficiently large number of samples for minimum end-to-end timing jitter. The actual clock signal is used at clock frequencies greater than 100 kHz.

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 0 to 76.8 Kbps asynchronously.

SECTION 5

MAINTENANCE AND TROUBLESHOOTING

5.1 INTRODUCTION

This chapter contains general information designed to isolate a malfunction in the Model F22XX 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.

Return to VERSITRON

Return Manuals Resource