Versitron Fiber Optic Modem Manuals Resource

F230X

FOM II Series

DS3

Fiber Optic Modem

Technical Manual

Revision E

Copyright January 2004

VERSITRON, Inc.

83 Albe Drive / Suite C

Newark, DE 19702

www.versitron.com

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 box in which the item is shipped.

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 OUTPUT CONNECTIONS

2.6 LOOPBACK

2.6.1 Remote Unit Loopback

2.6.2 Local Unit Loopback

2.7 INITIAL CHECKOUT PROCEDURE

 

SECTION 3: OPERATION

3.1 INTRODUCTION

3.2 STATUS INDICATORS

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

2. JUMPER AND SWITCH SETTINGS

Section 1

Description of Equipment

1.2 Introduction

This manual provides general and detailed information on the installation and operation of Model F230X FOM II Series DS3 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 F230X circuit card assembly.

1.2 DESCRIPTION OF EQUIPMENT

1.2.1 Functional Characteristics

Model F230X FOM II Series Fiber Optic Modems are designed to extend the interface of a DS3-standard signal. The fiber circuit consists of two modems connected by fiber cable and has data rates and electrical signal characteristics that conform to ANSI T1.404, AT&T 728A & B, Bellcore TR-NPL-000320, TR-NPL-000424, DSX-3 CB119 and CCITT G.703 & G.752 standards. Electrical DS3-standard 3-zero substitution (B3ZS) signals on coaxial cable are input via two 75* BNC connectors, encoded for optical transmission by one modem, transmitted over fiber cable to a second modem where the signal is decoded and output via two 75* BNC connectors. M13 and C-bit parity signals can be framed or unframed. Model F2304 Modems with 1300nm multimode LED optics operate at distances up to 2 Km (1.25mi/6,600ft) on multimode fiber cable. Model F2305 Modems with 1300nm single mode Lasers operate at distances up to 10 Km (6.25mi/33,000ft) on single mode fiber cable. Model F2305-3 Modems with 1300nm single mode long-haul Lasers operate at distances up to 30 Km (18.75mi/99,000ft) on single mode fiber cable.

1.2.2 Physical Characteristics

Model F230X Modems measure 7"W x 0.9"H x 12.2"L and are designed to be mounted in VERSITRON enclosures or chassis (see Table 1). Standalone options include single-card and dual-card enclosures. Rack mount options include 2-slot and 20-slot chassis. A separate VAC to VDC power adapter is needed for each modem installed in either standalone enclosure or in the 2-slot rack mount chassis. Each adapter uses the one-pin connector on the back of each modem for power input. There are two 75* coax connectors for the copper signal interface on the back of the modem. For the fiber interface two ST (F2304) or SC (F2305, F2305-3) connectors also located on the back of the modem. When installed in the 20-slot rack mount chassis the Model AC150W Power Supply provides power to the modem(s). Two Model AC150W Power Supplies are recommended for power redundancy. Model F230X Modems have five indicators: power on (PWR), alarm (ALM), transmit data present (TXD), system ready for synchronous reception (RXD), and remote loopback mode indicator (LOOP).

FIGURE 1. OVERALL VIEW, F230X MODEMS

 

Model	Dimensions	Description	PowerAdapter
HF-1 * (19052)	7.1" W x 1.3" H x 11.6" L	Single Card Standalone Enclosure	(LTWPS1212AP6)
HF-2 * (19053)	7.1" W x 2.3" H x 11.6" L	Dual Card Standalone Enclosure	(LTWPS1212AP6)
HF-2SS * (19629)	19" W x 1.7" H x 13.8" L	2-Slot Rack Mount Chassis (Side-by-Side)	(LTWPS1212AP6)
HF-20 (19032)	19" W x 7.1" H x 11.6" L	20-Slot Rack Mount Chassis	(19320-03)

* Note: One Power Adapter per DS3 Modem is required when installed in these Models.

TABLE 1. ENCLOSURES / CHASSIS

1.3 SPECIFICATIONS

Data Rate: 44.736 Mbps.

Data Format: B3ZS, framed or unframed.

Sampling Rate: 112 MHz, after serial-to-parallel conversion.

Protocol: Synchronous.

Operation: Full duplex over fiber optic cable pair.

Optical Interface: F2304 - ST connectors; F2305 or F2305-3 - SC connectors.

Digital Interface: Signal levels conform to ANSI T1.404, AT&T 728A & B, Bellcore TR-NPL-000320, TR-NPL-000424, DSX-3 CB119 and CCITT G.703 & G.752 standards.

Electrical Interface: Two 75* BNC connectors.

Bit Error Rate: Better than 10-12.

MTBF: 84,620 hrs.

Dimensions: 7.0W x 0.9H x 12.2L in. (17.8 x 2.3 x 31 cm).

Weight: 16.0 oz. (0.45 kg).

Power Requirements: Regulated 12 VDC @ 1.2A, 12 watts, 60Hz.

Environment: 0° to +50°C (32° to +122°F) operating temperature; up to 95% relative humidity (non-condensing); up to 10,000 feet altitude; storage temperature -40° to +70° C.

Model	F2304	F2305	F2305-3
Connector	ST	SC	SC
Wavelength	Multimode 1300nm	Single Mode 1300nm	Single Mode 1300nm
Link Budget*	19 1dB	16 1dB	24 1dB
Maximum Range*	2 Km (1.25mi/6,600ft)	10 Km (6.25mi/33,000ft)	30 Km (18.75mi/99,000ft)
Fiber Optic Cable	50/125, 62.5/125, 100/140	8/125, 9/125, 10/125	8/125, 9/125, 10/125

* Note: One Power Adapter per DS3 Modem is required when installed in these Models.

TABLE 1. ENCLOSURES / CHASSIS

Section 2

INSTALLATION

2.1 GENERAL

This section contains information on the installation and initial checkout of the F230X FOM II Series DS3 Modems. Paragraph 2.2 contains general information on site selection and rack mounting. Paragraphs 2.3 through 2.6 contain detailed instructions for connecting F230X units to your system and selecting the different options. Paragraph 2.7 contains initial checkout procedures.

2.2 SITE SELECTION AND MOUNTING

The F230X is designed to connect directly to the serial port (two 75* BNC connectors) of PBX or multiplexer equipment with cables (customer supplied). The F230X is designed to be mounted in a single-card (HF-1) or dual-card (HF-2) standalone enclosure or may be rack mounted in a 2-slot (HF-2SS) or 20-slot (HF-20) chassis.

2.3 POWER REQUIREMENTS

WARNING: Power must be supplied to the circuit board prior to connecting either the copper or fiber signal cables. This permits the programmable logic on the circuit card to initialize properly. Failure to supply power to the board first could result in incorrect functioning of the product.

The F230X is designed to operate from an AC power transformer or a DC power source with a DC voltage of +12 VDC, 1.2A. Before inserting the power transformer into an AC power source, the plug should be connected to the modem. No special tools required. DC power may be used instead of the power transformer 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 1.2A.

2.4 SWITCH SETTINGS

Each F230X has five switches on the circuit card. Only one, the loopback switch, labeled "SW1", is used after the initial configuration of the modem. The loopback switch is set from the front panel of the circuit card, should be set OFF for the initial configuration and installation. The loopback function is discussed in Section 2.6. The switches labeled "SW2", "SW4", "SW5", and "SW6" are used to reset the XILINX FPGA and the TX and RX TAXI chips. These are for diagnostic use only, and should never be touched. The 3-position switch labeled "SW3", near the edge of the card near the BNC connectors, is positioned such that the "ON" setting of each of the 3 switch positions is toward the FPGA (or "up" as the card is held vertically with the front panel to the left)

FIGURE 2. JUMPER AND SWITCH SETTINGS

2.5 OUTPUT CONNECTIONS

The F230X DS3 Modems transmit and receive bipolar, B3ZS-encoded signals using standard BNC connectors for the electrical signal interface.

2.6 LOOPBACK

The F230X has two loopback features. The first ("remote") allows the user to test the fiber optic circuitry of the local unit, and the copper/fiber circuitry of the remote unit. The second ("local") loops the individual unit to itself (a fiber optic patch cable is required for this test).

2.6.1 Remote Unit Loopback

A front panel loopback switch (LB) controls the F230X fiber optic inputs and outputs. When switched ON, optically received serial data from a remote terminal is converted from serial to parallel, reconverted back to serial and clocked back out via the optical transmitter. With the local and remote unit’s fiber systems and remote unit’s copper system working properly, the remote unit will experience a few errors and then re-sync to the incoming data. Meanwhile the local unit will have errors due to no data being transmitted through the local unit. This test proves that the optical interface circuitry of both units and the copper circuitry of the remote unit are operating properly.

2.6.2 Local Unit Loopback

For this loopback function, a small fiber optic patch cable is required. The patch cable is used to loop back the optical transmitter to the optical receiver. In a working unit, B3ZS data from the copper interface is encoded and transmitted through the optical circuit via fiber optic patch cord. The data is then received by the optical receiver and decoded back to B3ZS data stream. This procedure is used to test the optical and electrical circuits of an individual unit.

2.3.2 Installation with DC Power

DC power may be used instead of an AC power adapter, if available. This requires a 2.5 mm socket with the positive on the center and common on the concentric, and providing +12 VDC at 250mA.

2.7 INITIAL CHECKOUT PROCEDURE

WARNING: AVOID LOOKING INTO THE TRANSMITTER OPTICAL OUTPUT ONCE POWER IS APPLIED. EYE DAMAGE DUE TO LASER CAN OCCUR.

The F230X has no power on/off switch. Once installed and power is applied it is considered fully operational. The power indicator (PWR) should remain on as long as power is supplied. Upon initial power up, with no signal connections made, the power (PWR), system ready for synchronous reception (RXD), and alarm (ALM) LED indicators should be ON. When signal connections are properly made, the transmit data present (TXD) and system ready for synchronous reception (RXD) indicators should be ON and the ALM LED should go OFF. Before beginning system operation verify the following:

1. The PWR and RXD LEDs lit up when the power is applied to the modem.
2. The fiber optic cable is crossed transmit to receive from unit one to unit two.
3. The ALM LED goes out when fiber optic connections are applied to the F230X.
4. The TXD LED lights up when the BNC copper interface is connected.
5. The switch settings are correct for the circuit configuration.

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 F230X FOM II Series DS3 Modems. Since the F230X is designed for continuous and uninterrupted operation, there are no operating requirements. Once the F230X is powered up it should remain in service as long as required.

3.2 STATUS INDICATORS/AUDIBLE ALARM

There are five LED indicators on the F230X: power (PWR), alarm (ALM), transmit data present (TXD), system ready for synchronous reception (RXD), and remote loopback (LOOP). No audible alarm is available. The F230X contains alarm circuits to monitor the copper connection, optical connection and power supplies. The ALM LED is activated when there is no signal present at the fiber optic interface. The RXD LED comes ON when power is supplied to the unit and shows that the unit is ready for synchronous data reception. (NOTE: An additional red LED is located on the daughter board of the circuit card assembly which indicates a loss of copper signal on the transmit (IN) BNC connector.)

3.3 Operating Controls

The only operating control associated with the F230X is the front panel switch. The LB switch is used to enable the remote loopback capability of the circuit. This is described in Section 2.6 and is normally only used for diagnostic purposes when initializing or reconfiguring the system using the F230X. The switch settings onboard the circuit card are described in Table 2 in Section 2.4 and are set prior to first using the F230X. Further changes are not required unless the system requirements change.

SECTION 4

THEORY OF OPERATION

4.1 INTRODUCTION

The F230X FOM II Series DS3 Modems provide a transparent, synchronous path for DS3-standard signals. By converting to fiber optic signaling, distances of up to 2 Km (1.25mi/6,600ft) on multimode fiber optic cable or 30 Km (18.75mi/99,000ft) on single mode fiber optic cable may be traversed without the need for a repeater or amplifier. In addition, the use of fiber optic cable as the transmission medium provides EMI/RFI protection and data security.

In the F230X transmitter circuitry, the DS3-standard data and clock are received via the BNC connector, decoded from B3ZS, processed and transformed to TTL logic with a Field Programmable Gate Array (FPGA). The serial data stream is converted to an eight-bit parallel stream and synchronized. The signal is then converted into an optical signal input. The parallel data inputs are sampled using an AM7968 TAXI chip, at a rate of approximately 112 Mbps and a balanced +5V ECL signal format. The optical signal transmitter then sends the signal out onto the fiber optic cable.

Through the receiver circuitry of the F230X the same process occurs in reverse. First, the optical signal is received and converted back to an electrical signal. The TAXI receiver decodes the serial data stream. The data signal is then re-encoded to the B3ZS protocol and output to the BNC electrical signal interface. To the multiplexer or PBX terminal equipment connected to the F230X pair, the transition from copper to fiber and back is transparent.

SECTION 5

MAINTENANCE AND TROUBLESHOOTING

5.1 INTRODUCTION

This chapter contains general information designed to isolate a malfunction in the F230X 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 3 should be taken to check a non-operating modem. Contact VERSITRON Customer Service for additional diagnostic assistance or to arrange for repair as necessary.

STATUS INDICATOR	PROBABLE CAUSE	CORRECTIVE ACTION
POWER (PWR) LED is off.	No AC power.	Check that both ends of the transformer are connected.
	Blown Fuse.	Replace with 800 mA, 5 x 20 mm Slo-Blo fuse.
	Other power supply circuit problem.	Contact VERSITRON Customer Service for assistance.
ALARM (ALM) LED is on.	Incorrect optical signal level received at receiver input.	1. Check that fiber optic cable is properly connected to RX connector.
		2. Check that the remote unit power is on and the TX fiber optic connector is connected properly.
		3. Measure the optical levels on both ends (if possible) in order to check the optical link.
		4. Contact VERSITRON Customer Service for assistance.
DATA (TXD) LED is off or not responding as expected	No input on the BNC electrical interface connector.	Check that the switches are set for the correct electrical interface protocol. Check that the interface connector is 75 W and connected securely.
DATA (RXD) LED is off or not responding as expected.	Unit is not ready for synchronous data reception. Internal circuitry problem.	Contact VERSITRON Customer Service for assistance.
HF-20 chassis, SYSTEM ALARM LED is on.	No input on the BNC electrical interface connector.	Check that the switches are set for the correct electrical interface protocol. Check that the interface connector is 75 Ω and connected securely.

TABLE 3. 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.com