MEGAPLEX-2100 MODULE VC-16A. 16-Channel PCM/ADPCM Voice Module Installation and Operation Manual. Notice

Transcription

1 MEGAPLEX-2100 MODULE VC-1A 1-Channel PCM/ADPCM Voice Module Installation and Operation Manual Notice This manual contains information that is proprietary to RAD Data Communications No part of this publication may be reproduced in any form whatsoever without prior written approval by RAD Data Communications No representation or warranties for fitness for any purpose other than what is specifically mentioned in this manual is made either by RAD Data Communications or its agents For further information contact RAD Data Communications at the address below or contact your local distributor International Headquarters RAD Data Communications Ltd 2 Raoul Wallenberg St Tel Aviv 9719 Israel Tel: Fax: rad@radcoil US Headquarters RAD Data Communications Inc 900 Corporate Drive Mahwah, NJ 070 USA Tel: (201) Toll free: Fax: (201) market@radusacom 2000 RAD Data Communications Publication No /00

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3 Quick Start Guide If you are familiar with the product, use this guide to prepare it for operation To install a VC-1A module, perform the following steps: 1 Insert the module in the assigned I/O slot of the Megaplex chassis 2 Connect the cable from the user equipment to the VC-1A s -pin TELCO channel connector Configure the module as detailed below in the configuration procedure Configuration Procedure Start VC-1A configuration by entering the command: DEF CH A:*<Enter> The configuration parameters and the allowed range of values are listed below Table 1 General Parameters Parameter Coding Signaling Encoding Metering Range of Values a LAW u LAW NO SIGNALING PCM ADPCM N/A Table 2 Channel Parameters Parameter Connect Transmit Level Receive Level Wires Num Range of Values YES NO + to -10 dbm +2 to -17 dbm 2 WIRES WIRES Parameter Interface SigFeed Type Operation Mode Range of Values N/A N/A N/A BI-DIR Parameter ML Slot ML Channel Map Type Start Ts Range of Values IO-1 to IO-12 EX1 EX2 N/A N/A 1

4 Quick Start Guide VC-1A Installation and Operation Manual 2

5 Table of Contents VC-1A Installation and Operation Manual Contents CHAPTER 1 INTRODUCTION 11 Overview 1-1 User Interface Physical Description 1- Front Panel 1-1 Functional Description 1- Audio Performance 1- Timeslot Assignment 1- Flexible Main Link Selection 1- Handling of Signaling Information 1- Configuration and Management 1- Test and Diagnostic Capabilities 1-1 Technical Specifications 1- CHAPTER 2 MODULE INSTALLATION AND OPERATION 21 General Preparation for Installation Module Installation Module Connections 2-2 Connection of Voice Channels 2-2 CHAPTER CONFIGURATION INSTRUCTIONS 1 Introduction -1 2 Configuration Procedure -1 Module Parameters -1 Channel Parameters -2 CHAPTER TESTS AND DIAGNOSTICS 1 General -1 2 Test and Diagnostic Functions -1 Local Digital Loopback (Local Loop) -2 Remote Analog Loopback (Remote Loop) - Tone Injection - Backward Tone Injection - Alarm Messages - Troubleshooting Instructions - Recommended Test Sequence - APPENDIX A CONNECTOR DATA A1 VC-1A Connector A-1 i

6 VC-1A Installation and Operation Manual Table of Contents List of Figures Figure 1-1 Basic Application for VC-1A Modules 1-2 Figure 1-2 Dual-E1 Multipoint Application Supporting up to 12 Channels 1-2 Figure 1- T1 Application Supporting up to 1 Channels 1-2 Figure 1- VC-1A Module Panel 1- Figure -1 Selection of Transmit and Receive Levels - Figure -1 Local Loop, Signal Path -2 Figure -2 Remote Loop, Signal Path - Figure - Test Tone Injection Path - Figure - Backward Test Tone Injection Path - List of Tables Table 1-1 Maximum Channels Supported by Megaplex Configurations 1- Table -1 Module Parameters -1 Table -2 Channel Parameters -2 Table -1 VC-1A Alarm Messages - Table A-1 TELCO Connector Pin Assignment A-1 ii

7 Chapter 1 Introduction 11 Overview This manual describes the technical characteristics, applications, installation and operation of the VC-1A voice interface module The VC-1A is a user-programmable voice interface module for the modular E1/T1 multiplexer systems Megaplex-2100 and Megaplex-210 VC-1A transmits voice without any channel signaling, It is thus intended primarily for basic point-to-point applications which do not require signaling, or use only in-band signaling (DTMF for example) For flexibility, any channel can be independently routed to a different main link The VC-1A module provides 1 voice channels using one of two user-selectable voice encoding modes: Toll-quality kbps PCM voice encoding in compliance with ITU-T Rec G711 and AT&T Pub 801 Toll-quality 2 kbps ADPCM voice compression encoding in compliance with ITU-T Rec G72 and G72 (1988), ANSI T The VC-1A modules maximize the Megaplex-2100 utilization: for example, a single Megaplex-2100 or Megaplex-210 unit, operating in PCM encoding mode, can carry up to 2 voice channels over two E1 links (or up to 8 channels over two T1 links) 9 PCM voice channels can be carried over three E1 links (or up to 72 channels over three T1 links) In ADPCM encoding mode, each channels requires only half a timeslot Therefore when using ADPCM mode, a single E1 link can carry up to 2 voice channels and a single T1 link can carry up to 8 voice channels This enables, for example, a single Megaplex-2100 unit to support 1 voice channels over three T1 links Note In this manual the generic term Megaplex is used when the information is applicable to both the Megaplex-2100 and Megaplex-210 chassis types The complete designation is used only for information applicable to a specific version User Interface The analog interface type for the module can be user-selected for either 2-wire or -wire The interface type is independently selected per channel Overview 1-1

8 Chapter 1 Introduction VC-1A Installation and Operation Manual All 1 channels are terminated on a single -pin TELCO connector RAD offers an adapter cable, CBL-VC1A, terminated in 1 x RJ- male connectors, for direct connection to user's equipment Applications Figure 1-1 shows a basic tie line extension application using VC-1A modules 1 Tie Lines 1 Tie Lines E1/T1 VC-1A VC-1A PBX PBX MP-2100 MP-2100 Figure 1-1 Basic Application for VC-1A Modules In this application each VC-1A module supports 1 PBX E&M tie lines The E1/T1 link between the Megaplex systems establishes the transmission media between the PBXs In the Figure 1-2 application, using ADPCM, up to 12 voice channels can be transmitted by a single Megaplex-2100 over two E1 links Channels can be independently routed to either of the two Megaplex-210 remote site 2 Channels VC-1A modules 12 Channels E1 MP-210 PBX VC-1A modules MP-2100 E1 2 Channels VC-1A modules MP-210 Figure 1-2 Dual-E1 Multipoint Application Supporting up to 12 Channels In the application shown in Figure 1-, using ADPCM, up to 1 voice channels can be transmitted by a single Megaplex-2100 over three T1 links PBX 1 Channels VC-1A modules T1 T1 T1 Network MP-2100 Figure 1- T1 Application Supporting up to 1 Channels 1-2 Overview

9 VC-1A Installation and Operation Manual Chapter 1 Introduction Front Panel 12 Physical Description The VC-1A module, U in height, occupies a single module slot in the Megaplex chassis Figure 1- shows the panel of the VC-1A module The VC-1A panel includes a single female -pin TELCO connector that supports all 1 voice channels There are no LED indicators VC-1A Voice Channel Connector (for all 1 channels) CH 1-1 Figure 1- VC-1A Module Panel Audio Performance 1 Functional Description The VC-1A module provides 1 high-quality voice channels The voice encoding method used is user-selectable for either toll-quality kbps PCM in compliance with ITU-T Rec G711 and AT&T Pub 801 or 2 kbps ADPCM in compliance with ITU-T Rec G72 and G72 (1988), ANSI T The encoding method chosen is in effect for all 1 channels The user can select the companding law, µ-law or A-law, in accordance with system requirements To increase application flexibility, the nominal audio transmit and receive levels of each channel can be individually adjusted over a wide range Due to the high quality audio reproduction, DTMF signaling is transparently transferred, in-band Therefore, the user can use DTMF signaling as usual, eg, can operate the telephone set keypad to access voice mail systems, interactive systems, etc Functional Description 1-

10 Chapter 1 Introduction VC-1A Installation and Operation Manual Timeslot Assignment The main link bandwidth required by a VC-1A module depends on the encoding method, PCM or ADPCM: With PCM encoding, the VC-1A modules require one main link timeslot, per voice channel, and provide the data in a DS-0 (8-bits) compatible format, permitting voice channel switching in a DACs based system With ADPCM encoding, the VC-1A modules requires only half a main link timeslot for each voice channel (two channels can share a single timeslot) Six VC-1A modules can be installed in a single Megaplex-2100 chassis, to support a maximum of 9 PCM voice channels using three E1 links Using ADPCM compression mode, a single Megaplex-2100 chassis equipped with eight VC-1A modules, can support up to 12 channels using two E1 links For a T1 Megaplex-2100 system, a single chassis equipped with nine VC-1A modules, can support a maximum of 1 channels using three T1 links Since the maximum number of VC-1A modules that can be installed in the compact Megaplex-210 chassis is four (one slot is occupied by the main link module), the maximum number of channels that can be supported by a dual-link E1 system is 2 channels using PCM, or channels using ADPCM For a dual-link T1 system, the maximum number of channels is 8 channels using PCM, or channels using ADPCM Alternatively, a Megaplex-210 using ADPCM, can support 2 channels over a single E1, or 8 channels over a single T1 See Table 1-1 for a summary of the maximum number of channels achieved, according to the various Megaplex chassis, main link type/number, VC-1A module number, and encoding mode used Flexible Main Link Selection Handling of Signaling Information The Megaplex systems enables the user to independently select the main link that will carry each of the VC-1A s channels For this purpose, the user can specify both the main link module (ML Slot) and its port (ML Channel) desired This flexible channel routing, enables selected voice channels to be routed to different locations The VC-1A module processes only voice and does not transmit any channel associated signaling information (For E1 systems, this results in an additional timeslot free to be utilized for carrying voice and thus 1 PCM channels can be supported rather than the conventional 0) 1- Functional Description

11 VC-1A Installation and Operation Manual Chapter 1 Introduction Table 1-1 Maximum Channels Supported by Megaplex Configurations Megaplex chassis/link type Encoding No of links No of VC-1A installed MP-2100 PCM (1) with E1 links 2 2 (2) 9 (9) ADPCM 1 2 (1) (2) (80) MP-2100 PCM (2) with T1 links 2 8 (8) 72 (72) ADPCM 1 8 (2) 2 9 (8) 9 1 (72) MP-210 PCM (1) with E1 links 2 2 (2) ADPCM 1 2 (1) 2 (2) MP-210 PCM (2) with T1 links 2 8 (8) ADPCM 1 8 (2) 2 (2) Max no of channels supported (timeslots utilized) Configuration and Management Test and Diagnostic Capabilities All the VC-1A modules operating parameters are controlled by means of the Megaplex system management The VC-1A module automatically performs self-test upon power-up and during normal operation The diagnostic features include: Local digital loopback per channel towards local analog side Remote analog loopback per channel towards remote side 1 khz, 0 dbm0, tone injection per channel towards remote side 1 khz, 0 dbm0, tone injection per channel towards local side Using these functions, the user can check rapidly and efficiently the local/remote equipment and its connection to the module channel The user can request that a loopback (or the test tone injection) is automatically deactivated after a user-selected interval, thereby reducing the management workload during system troubleshooting Functional Description 1-

12 Chapter 1 Introduction VC-1A Installation and Operation Manual 1 Technical Specifications Number of Channels 1 Bandwidth Requirements PCM: kbps per enabled channel (one timeslot) ADPCM: 2 kbps per enabled channel (1/2 timeslot) Voice Encoding Technique Modulation Technique PCM: per ITU-T Rec G711 and AT&T Pub 801 ADPCM: per ITU-T G72 Companding µ-law or A-law (soft-selectable) Analog Interface Line Type -wire or 2-wire (soft-selectable) ITU-T Recommendations 2-wire: ITU-T Rec G71 -wire: ITU-T Rec G712, G71 Analog Parameters Nominal Level 0 dbm Nominal Impedance 00 Ω Return Loss (ERL) at 00 to 00 Hz Better than 20 db Frequency Response (Ref: 1020 Hz) 0 db ±0 db, at 00 to 000 Hz 0 db ±11 db, at 20 to 00 Hz Level adjustment (soft-selectable) TX: + to -10 dbm RX: +2 to -17 dbm Steps: 0 db (±01 db), nominal Signal to Total Distortion (8-bit PCM ITU-T Rec G712, G71 Method 2: encoding) 0 to -0 dbm0: better than db + to - dbm0: better than 22 db Idle Channel Noise Better than -70 dbm0 (+20 dbrnc) Transformer Isolation 100 VRMS Diagnostics Local digital loopback per channel, towards the local user equipment Remote analog loopback per channel, towards the remote user equipment 1 khz, 0 dbm0 test tone inject per channel, towards the remote user equipment 1 khz, 0 dbm0 backward test tone inject per channel, towards the local user equipment Self test for entire system upon power up Connector Single female -pin TELCO connector (for all 1 channels) Configuration Programmable via the system management 1- Technical Specifications

13 Chapter 2 Module Installation and Operation 21 General This chapter provides installation and operation instructions for the various VC-1A modules The information presented in this chapter supplements the general Megaplex-2100 installation, configuration and operation instructions contained in the Megaplex-2100 System Installation and Operation Manual Warning Before performing any internal settings, adjustment, maintenance, or repairs, first disconnect all the cables from the module, and then remove the module from the Megaplex enclosure No internal settings, adjustment, maintenance, and repairs may be performed by either the operator or the user; such activities may be performed only by a skilled technician who is aware of the hazards involved Always observe standard safety precautions during installation, operation, and maintenance of this product Caution The VC-1A modules contain components sensitive to electrostatic discharge (ESD) To prevent ESD damage, always hold the module by its sides, and do not touch the module components or connectors 22 Preparation for Installation VC-1A module versions does not include any internal user settings, and all configuration functions are programmable Preparation for Installation 2-1

14 Chapter 2 Module Installation and Operation VC-1A Installation and Operation Manual 2 Module Installation Refer to the system installation plan, and insert the module in the assigned I/O slot of the Megaplex enclosure The module starts operating as soon as it is plugged into an operating enclosure 2 Module Connections Connection of Voice Channels All 1 voice channels are terminated on a single female -pin TELCO connector Connector pin assignment is described in Appendix A You may either connect a cable prepared in accordance with Appendix A to the TELCO connector of the module, or use an adapter cable for direct connection to the equipment using the voice channels A suitable cable, designated CBL-VC-1A, is available as an option from RAD: this cable has a male TELCO -pin connector for connection to the VC-1A, and 1 x RJ- male connectors (one for each channel) for direct connection to the user's equipment Cable length is 1 meters ( feet) 2-2 Module Connections

15 Chapter Configuration Instructions 1 Introduction This chapter provides information on the configuration parameters of the VC-1A module The configuration activities required to select the desired values of these parameters are performed by means of the management system used to control the Megaplex-2100 systems The instructions appearing in this chapter assume that you are familiar with the management system being used: supervision terminal or Telnet (covered by the Megaplex-2100 System Installation and Operation Manual), or a network management system, eg, the RADview network management system (refer to the RADview User's Manual for instructions) 2 Configuration Procedure Module Parameters Table -1 explains the programmable VC-1A general module parameters, and their range of values Table -1 Module Parameters Parameter Coding Signaling Encoding Metering Description Specifies the companding law to be used by the voice channels: a LAW A-law coding, intended for use on E1 links u LAW µ-law coding, intended for use on T1 links Default: a LAW Not used This field is always set to NO SIGNALING (no transfer of channel signaling) Specifies the voice encoding employed on all channels: PCM kbps rate per channel (1 timeslot) ADPCM 2 kbps rate per channel (½ timeslot) Default: PCM Not used Always set to N/A Configuration Procedure -1

16 Chapter Configuration Instructions VC-1A Installation and Operation Manual Channel Parameters Table -2 explains the programmable channel (identified as Port EX01 through Port EX1) parameters, and their range of values Table -2 Channel Parameters Parameter Connect Transmit Level Receive Level Wires Num Interface Sig Feed Type Operation Mode ML Slot ML Channel Description Determines whether the channel is connected to the main link: YES channel is connected NO channel is disconnected You can still program the desired parameters, so that the channel will be ready for operation when needed Default: NO Selects the nominal input level of the transmit path within the range of: + to -10 dbm (in 0 db steps) Select the transmit level to match the transmission level point (TLP-transmit) of the equipment connected to the channel Figure -1 explains how to determine the required level setting Note: The application of an input signal at the nominal transmit level results in 0dBm digital level, and a far-end output signal equal to the far-end nominal receive level Default: 00 Selects the nominal output level of the receive path within the range of: +2 to -17 dbm (in 0 db steps) Select the receive level to match the TLP-receive of the equipment connected to the channel (see Figure -1) Default: 00 Specifies the interface type to be used by the voice channel: WIRES -wire interface 2 WIRES 2-wire interface Default: 2 WIRES Not used Always set to N/A Not used Always set to N/A Not used Always set to N/A Must always be set to BI-DIR for normal bi-directional (point-to-point) operation Other values are currently not used Default: BI-DIR Selects the main link module to which the channel will be connected The main link module is specified by indicating the number of the I/O slot in which the desired main link module is installed: IO-1 to IO-12 Default: IO-1 Selects the channel (link) of the main link module to which the channel will be connected: EX1 or EX2 Default: EX1-2 Configuration Procedure

17 VC-1A Installation and Operation Manual Chapter Configuration Instructions Table -2 Channel Parameters (Cont) Parameter Description Map Type Start Ts Currently not used Always set to N/A Currently not used Always set to N/A VC-1 A Channel Transmit TLP: -10 B T R Transmit Input Circuit Nominal Level = 0 dbm Adjust Level to -10dBm Signal Processor Receive TLP: -2dB T1 R1 Receive Output Circuit Adjust Level to -2dBm Figure -1 Selection of Transmit and Receive Levels Timeslot Assignment After performing the configuration of the individual module channels, it is necessary to assign a main link timeslot to each connected channel, as explained in the Megaplex-2100 System Installation and Operation Manual Configuration Procedure -

18 Chapter Configuration Instructions VC-1A Installation and Operation Manual - Configuration Procedure

19 Chapter Tests and Diagnostics 1 General This chapter explains the module specific tests and diagnostic functions, provides information on the alarms generated by the VC-1A modules and troubleshooting instructions The diagnostic information presented in this chapter supplements the general Megaplex-2100 diagnostics operation instructions contained in the Megaplex-2100 System Installation and Operation Manual 2 Test and Diagnostic Functions The available test and diagnostics functions are: Local digital loopback on the desired module channel Remote digital loopback on the desired module channel Tone Injection Backward tone Injection The VC-1A modules have a complete set of test loops that includes local digital loops on each channel Remote analog loops can also be run on each channel In addition, the VC-1A modules have provisions for the digital injection of a test tone towards either the local or remote subscriber The tone is sent instead of the local transmit signal, and provides a controlled test signal that allows rapid testing: the tone should be received by the remote subscriber at the nominal receive level, and should be heard loudly and clearly In the case of the backward tone injection, the tone is sent instead of the local receive signal and should be received by the local subscriber at the nominal receive level When a test or loopback is activated, the user can also specify the time it remains active: the range is 1 through 0 minutes, in 1-minute steps After the specified time, the test or loopback is automatically deactivated, thereby reducing the management workload during system troubleshooting The default selection is continuous connection, that is, the test or loopback remain active until canceled by a user's command The following sections describe the available diagnostic activities Test and Diagnostic Functions -1

20 Chapter Tests and Diagnostics VC-1A Installation and Operation Manual Local Digital Loopback (Local Loop) The local loop is a digital loop performed at the digital output of the channel COMBO, by returning the transmit signal of the channel in the same timeslot of the receive path The transmit signal is still sent to the remote Megaplex unit The local loop is run per channel The loopback signal path is shown in Figure -1 User or Test Equipment Channel 1 Channel 1 VC-1A I/O Modules Local Unit Remote Unit VC-1A I/O Modules User or Test Equipment System Management Figure -1 Local Loop, Signal Path -2 Test and Diagnostic Functions

21 VC-1A Installation and Operation Manual Chapter Tests and Diagnostics Remote Analog Loopback (Remote Loop) The remote loop is an analog loop performed at the analog output of the channel COMBO, by returning the analog receive signal of the channel to the input of the transmit path The receive signal remains connected to the local user, and can be received by user While the loop is connected, the remote voice channel should receive its own signal, eg, a strong sidetone should be heard in the earpiece if the channel is connected to a telephone set The remote loop is run per channel The loopback signal path is shown in Figure -2 User or Test Equipment Channel 1 Channel 1 VC-1A I/O Modules Local Unit Remote Unit VC-1A I/O Modules User or Test Equipment System Management Figure -2 Remote Loop, Signal Path Test and Diagnostic Functions -

22 Chapter Tests and Diagnostics VC-1A Installation and Operation Manual Tone Injection The test tone is a data sequence repeating at a rate of 1 khz This data sequence is identical to the data sequence that would have been generated if a 1-kHz signal having a nominal level of 1 mw (0 dbm0) were applied to the input of the channel codec The tone is injected to the local transmit path multiplexer towards the remote side, instead of the transmit signal of the channel Note that the signal received from the remote end is also disconnected from the local subscriber The tone injection is per channel, but tone injections can be run on multiple channels simultaneously Figure - shows the signal path User or Test Equipment Channel 1 Channel 1 ~ Test Tone VC-1A I/O Modules Local Unit Remote Unit VC-1A I/O Modules User or Test Equipment System Management Figure - Test Tone Injection Path - Test and Diagnostic Functions

23 VC-1A Installation and Operation Manual Chapter Tests and Diagnostics Backward Tone Injection Similar to the tone injection described above, the backward test tone injection is a data sequence repeating at a rate of 1 khz However, the backwards tone injection is applied towards the local side The tone is injected to the local receive path, instead of the signal that was received from the remote end The signal from the local subscriber continues to be transmitted to the remote side The backwards tone injection is per channel, but backwards tone injections can be run on multiple channels simultaneously Figure - shows the signal path User or Test Equipment Channel 1 Channel 1 ~ Test Tone VC-1A I/O Modules Local Unit Remote Unit VC-1A I/O Modules User or Test Equipment System Management Figure - Backward Test Tone Injection Path Test and Diagnostic Functions -

24 Chapter Tests and Diagnostics VC-1A Installation and Operation Manual Alarm Messages Table -1 lists the specific alarm messages generated by the VC-1A module, specifies their type, and explains their interpretation The module generates additional alarm messages, which are not specific to VC-1A modules; these messages are explained in Alarms appendix of the Megaplex-2100 System Installation and Operation Manual Table -1 VC-1A Alarm Messages Code Message Type Interpretation 021 MODULE WAS REMOVED Event The module has been taken out of its slot 022 MODULE WAS INSERTED Event The module has been inserted 02 RESET OCCURRED Event The module has been automatically reset 02 HARDWARE/INIT FAILURE Major Module initialization, performed upon turn-on or module insertion, has failed, or a hardware malfunction has been detected in this module 02 NOT PROGRAMMED MODULE Minor The module that has been read from the Megaplex unit is not programmed in the active data base 02 MODULE TYPE MISMATCH Major The module that has been read from the Megaplex unit does not match the module programmed in the active data base 028 HARDWARE/SOFTWARE MISMATCH 029 NOT SUPPORTED SOFTWARE VER Major State There is a conflict between the setting of configuration parameters and the setting of hardware/jumpers The VC-1A module includes an old software version that differs from the version expected by the CL module 01 COMMUNICATION FAILURE Event The CL module reported a temporary failure in the communication with I/O modules 10 COMBO FAILURE IN CH1 COMBO FAILURE IN CH2 through COMBO FAILURE IN CH1 Major The COMBO of the specified channel failed This state is often reported because of a transient fault If the fault state persists, the module must be repaired as soon as possible Troubleshooting Instructions Recommended Test Sequence The test tone injection function and the loops available on the VC-1A module provide a rapid and efficient way to identify the general location of a fault at either of the two VC-1A modules connected in a link, in the external equipment, or in the connections to the channels If a complaint is received from one of the subscribers connected to the VC-1A channels, first activate the VC-1A local test loop at the side where - Troubleshooting Instructions

25 VC-1A Installation and Operation Manual Chapter Tests and Diagnostics the complaint is received from The local subscriber must receive its own signal If the signal is not received, the problem is at the local end: Check the connections to the subscriber equipment Replace the local VC-1A module If the local subscriber receives its own signal when the local loop is activated, activate test tone injection toward the complaining subscriber If the subscriber receives the test tone, the problem is probably in the connections at the remote side (the side that sends the tone) You can check the computer path of the remote module channel by activating the remote loopback and the tone injection toward the remote subscriber, and checking that the local subscriber receives the test tone If the problem is not corrected, the procedure must be repeated at the other side of the link Deactivate the local loop and activate the remote loop on the remote Megaplex unit Troubleshooting Instructions -7

26 Chapter Tests and Diagnostics VC-1A Installation and Operation Manual -8 Troubleshooting Instructions

27 Appendix A Connector Data A1 VC-1A Connector The VC-1A modules have a single female -pin TELCO connector, wired in accordance with Table A-1 Table A-1 also details the pin assignment of the CBL-VC1A cable, which is used to adapt between the module s TELCO connector and 1 x RJ- male connectors Table A-1 TELCO Connector Pin Assignment Channel TELCO Connector Pin CBL-VC1A RJ- Pin Function TELCO Connector Pin CBL-VC1A RJ- Pin Function wire RX in -wire TX out 2 -wire RX in -wire TX out -wire RX in 7 8 -wire TX out 7 8 -wire RX in 9 0 -wire TX out wire RX in 1 2 -wire TX out wire RX in -wire TX out wire RX in -wire TX out wire RX in 7 8 -wire TX out wire RX in 9 0 -wire TX out wire RX in 1 2 -wire TX out wire RX in -wire TX out wire RX in -wire TX out wire RX in 7 8 -wire TX out wire RX in 9 0 -wire TX out wire RX in 1 2 -wire TX out wire RX in -wire TX out VC-1A Connector A-1

28 Appendix A Connector Data VC-1A Installation and Operation Manual A-2 VC-1A Connector