CXR MD200 User manual

Instruction Manual MD 2000
MD 2000
mDSL MODEM
Installation
& Operation Manual
P/N: 8000 601 620
Revision: 0B
CXR Telcom Corporation
894 Faulstich Court
San Jose, CA 95112
Tel: [phone]
Fax: [phone]
Email: [email protected]
www.cxr.com
MD 2000 - Page 1

Instruction Manual MD 2000
Warning
This publication contains information that is the property of CXR Anderson Jacobson. No part of this publication may be copied,
photocopied, reproduced, translated, or reduced to any electronic medium or machine readable form without prior written consent of
CXR Anderson Jacobson. Information in this publication is subject to change without notice. CXR Anderson Jacobson assumes no
responsibility for errors or omissions in this publication or for the use of this material. All rights reserved. Copyright 2002, CXR
Anderson Jacobson.
The purpose of this manual is to provide information and installation instructions CXR reserves the rights to improve its products and
specifications without notice. CXR has made every effort to provide the best possible quality in writing this manual but cannot be held
responsible for any damage, which could result from errors or improper description of the equipment, its characteristics and operation.
Please read and enforce the safety instructions of the safety and installation chapters.
The team at CXR Anderson Jacobson thanks you for choosing the MD2000 mDSL modem
We hope that this equipment will provide full satisfaction and in order to serve you even better, we thank you for returning the warranty
card you will find at the end of this manual.
We also invite you to read the last part of this manual, which provides useful information on the warranty terms and conditions, which
apply to your equipment.
Foreword
This manual describes how to install, operate and troubleshoot the MD 2000.
Chapter 1 Characteristics and typical configurations
Chapter 2 How to install and connect the equipment
Chapter 3 The front panel displays and switches as well as their use
Chapter 4 Examples of typical applications
Chapter 5How to configure the equipment
Chapter 6The V.11 and V.35 DTE interfaces
Chapter 7The 10BT and HUB DTE interfaces
Chapter 8The E1 G.703/G.704 line interface
Chapter 9The T1 G.703/G.704 line interface
Chapter 10 The J64 G.703-64 Kbps interface
Chapter 11 The V28 - RS232 interface
Chapter 12 Test and the error rate statistics provided by the modem
Chapter 13 The operation of the internal memory
Chapter 14 Lists all the MD 2000 technical characteristics
Chapter 15 Will help you to resolve most of the difficulties encountered during the installation and operation of the modem.
MD 2000 - Page 2

Instruction Manual MD 2000
Table of Contents
1INTRODUCTION........................................................................................................................................................................... 8
1.1 DTE INTERFACES..................................................................................................................................................................... 9
1.2 CONDITIONING ......................................................................................................................................................................... 9
1.3 INSTALLATION AND INITIAL SET-UP........................................................................................................................................... 10
1.4 CONFIGURATION .................................................................................................................................................................... 10
1.5 FACTORY CONFIGURATIONS ................................................................................................................................................... 10
1.6 ALARM RELAYS....................................................................................................................................................................... 11
1.7 G.703/G.704 INTERFACE ....................................................................................................................................................... 11
1.8 APPLICATION EXAMPLES......................................................................................................................................................... 11
2INSTALLATION.......................................................................................................................................................................... 12
2.1 DESKTOP MODEM .................................................................................................................................................................. 12
2.1.1 Accessories ...................................................................................................................................................................... 12
2.1.2 Connections...................................................................................................................................................................... 12
2.1.3 Powering........................................................................................................................................................................... 13
2.2 RACK MOUNT MODEM............................................................................................................................................................. 13
2.2.1 Accessories ...................................................................................................................................................................... 13
2.2.2 Installation......................................................................................................................................................................... 13
2.2.3 Connections...................................................................................................................................................................... 13
2.2.4 Powering........................................................................................................................................................................... 14
2.3 AUTOMATIC SELF-TEST.......................................................................................................................................................... 14
3DISPLAY AND SWITCHES........................................................................................................................................................ 15
3.1 FRONT PANEL WITH LED’S..................................................................................................................................................... 15
3.1.1 LED Display...................................................................................................................................................................... 15
3.1.2 The push button................................................................................................................................................................ 16
4TYPICAL APPLICATIONS ......................................................................................................................................................... 17
4.1 INITIALIZATION........................................................................................................................................................................ 17
4.2 E1 /T1 G.704 LINK ............................................................................................................................................................... 17
4.3 LAN TO LAN CONNECTION ..................................................................................................................................................... 18
4.4 X.21-V.35 TERMINAL CONNECTION ......................................................................................................................................... 18
4.5 G.704 TO J64 (G.703 -64 KBPS)CONNECTION....................................................................................................................... 19
5OPERATION AND CONFIGURATION....................................................................................................................................... 20
5.1 FACTORY AND USER CONFIGURATIONS................................................................................................................................... 20
5.2 VT100 INTERACTIVE MENUS .................................................................................................................................................. 20
5.3 AT COMMAND MODE.............................................................................................................................................................. 23
5.4 GENERAL PARAMETERS AND COMMANDS................................................................................................................................24
5.4.1 Connection Configuration................................................................................................................................................. 24
5.4.2 Configuration and Control................................................................................................................................................. 26
5.4.3 Security............................................................................................................................................................................. 27
5.4.4 Tests................................................................................................................................................................................. 28
Table of Contents (continued)
6X.21 - V.11 AND V.35 INTERFACES ........................................................................................................................................ 30
6.1 GENERAL............................................................................................................................................................................... 30
6.2 INTERFACE CONFIGURATION................................................................................................................................................... 30
6.2.1 X.21 - V.11 Interface Configuration .................................................................................................................................. 31
6.2.2 V.35 Interface Configuration............................................................................................................................................. 31
6.3 WIRING.................................................................................................................................................................................. 32
710BT AND 8 PORT HUB BRIDGE INTERFACE....................................................................................................................... 33
7.1 GENERAL............................................................................................................................................................................... 33
7.2 INTERFACE CONFIGURATION................................................................................................................................................... 34
7.3 WIRING OF THE RJ-45 CONNECTOR........................................................................................................................................ 34
7.3.1 RJ-45 on the 10BT Bridge................................................................................................................................................ 34
7.3.2 RJ-45 on the HUB 8 port Bridge....................................................................................................................................... 35
8E1 G.703-G.704 INTERFACE CONFIGURATION ..................................................................................................................... 36
8.1 GENERAL............................................................................................................................................................................... 36
8.2 E1 INTERFACE CONFIGURATION.............................................................................................................................................. 38
8.3 RJ-45 CONNECTOR WIRING ................................................................................................................................................... 39
9T1 G.703-G.704 INTERFACE CONFIGURATION...................................................................................................................... 40
MD 2000 - Page 3

Instruction Manual MD 2000
9.1 GENERAL............................................................................................................................................................................... 40
9.2 T1 INTERFACE CONFIGURATION.............................................................................................................................................. 42
9.3 RJ-45 CONNECTOR WIRING ................................................................................................................................................... 43
10 64 KBPS G.703 / J64 INTERFACE CONFIGURATION............................................................................................................. 44
10.1 GENERAL............................................................................................................................................................................... 44
10.2 J64 INTERFACE CONFIGURATION ............................................................................................................................................ 44
10.3 RJ-45 CONNECTOR WIRING ................................................................................................................................................... 44
11 V28 - RS232 INTERFACE CONFIGURATION........................................................................................................................... 45
11.1 GENERAL............................................................................................................................................................................... 45
11.2 ASYNCHRONOUS MODE .......................................................................................................................................................... 45
11.3 INTERFACE CONFIGURATION................................................................................................................................................... 46
11.4 WIRING.................................................................................................................................................................................. 47
12 DIAGNOSTICS AND TESTS...................................................................................................................................................... 48
12.1 DIAGNOSTICS......................................................................................................................................................................... 48
12.1.1 Connection Status......................................................................................................................................................... 48
12.1.2 Connection Duration ..................................................................................................................................................... 48
12.1.3 Statistics........................................................................................................................................................................ 49
12.2 TEST...................................................................................................................................................................................... 49
12.2.1 Local Analog Loop ........................................................................................................................................................ 49
12.2.2 Remote Digital Loop...................................................................................................................................................... 49
13 MEMORIES................................................................................................................................................................................. 50
14 TECHNICAL CHARACTERISTICS ............................................................................................................................................ 51
14.1 TRANSMISSION MODES........................................................................................................................................................... 51
14.2 GENERAL CHARACTERISTICS .........................................................................................................52
15 TROUBLESHOOTING................................................................................................................................................................ 53
15.1 POWER-UP PHASE ................................................................................................................................................................. 53
15.2 HANDSHAKE AND TRAINING..................................................................................................................................................... 54
15.3 LINE EVALUATION................................................................................................................................................................... 55
15.3.1 Loop resistance............................................................................................................................................................. 55
15.3.2 Loss at 400 KHz............................................................................................................................................................ 55
15.3.3 Frequency Response Vs Rate...................................................................................................................................... 55
15.3.4 Resume......................................................................................................................................................................... 55
16 APPENDIX .................................................................................................................................................................................. 56
16.1 APPENDIX A–WIRING............................................................................................................................................................ 56
16.1.1 Serial Control Port - RJ-45............................................................................................................................................ 56
16.1.2 RJ11 - Line Jack ........................................................................................................................................................... 56
16.1.3 Jack – Alarm Relay....................................................................................................................................................... 57
16.2 APPENDIX B:PRODUCT LINE WARRANTY.............................................................................................................................. 58
MD 2000 - Page 4

Instruction Manual MD 2000
Convention, product range and options
The CXR-AJ mDSL modems consist of a series of configurations or the MD 2000. Although they are very similar they differ in the
following characteristics:
Characteristics MD 2000
Maximal rate 4.64 Mbps
Automatic mode Yes
The equipment is supplied under different versions according to:
•
•
•
•
The type of Terminal interface: V.35 10Base-T, HUB, G.703/G.704 (T1 and E1), V.11/X.21.
The type of power supply: 110/230 V AC internal or external, 48 V DC internal
The type of front panel: LED display
The type of housing: Desktop or rack-mount
These different versions are summarized in the following table. The same designations will be used throughout this manual to identify
the differences between versions when applicable.
Desktop Rack mountable card
V
ersions
Characteristics 2011 2035 20BT 20HUB 2703 20T1 2064 1064 1028 1011 1035
V28-V24 - RS232 interface
z
V.11-X.21 interface z
z
V.35 interface z
z
10BT filtering bridge
z
Bridge + HUB 8 port interface z
E1 G.703-G.704 interface z
T1 G.704 interface
z
64K-J64 interface
zz
LED front panel Px
Internal 110 / 230 VAC xI
External 110 - 230 VAC xV
Internal 48 VDC xC
RACK MOUNT FOR AMS 4 / 16 xR
Example: The MD 2035 PIU is the model number for a desktop version equipped with a V.35 interface, a LED display and an internal
110VAC power supply.
The letter “X” used at the end of the model number designates the country version (example: U for USA). Although all versions have the
same characteristics, differences exist in the type power supply or power cord used as well as the language in which the manual is
written. For more information on country specific versions, please contact your sales representative.
V.35 and X.21-V.11 cables are available as an option:
•V.35: CXR reference CA.601.460
•X.21-V.11 (DB15): CXR reference CA.601.461
Important Information
This equipment complies with the requirement in part 15 of FCC rules for a class B computing device.
Only accessories provided with the unit and shielded terminal cables should be connected to the equipment.
MD 2000 - Page 5

Instruction Manual MD 2000
Safety Instructions
This equipment meets the safety requirements of the UL 1950 standard.
The following accesses are referenced as safety low voltages:
•5 VDC Input of the MD2000 / xV desktop unit
•48 VDC Input of the MD2000 / xC desktop unit
•Line: xDSL leased line connection
•Control : V.24 - RS232 configuration port
•DTE – V.11: V.11-X.21 interface of the MD 2011 and MD 1011 modems
•DTE – V.35: V.35 interface of the MD 2035 modems
•DTE - 10BT: Ethernet interface on the MD 20BT modem
•DTE - HUB: 8 port HUB Ethernet interfaces on the MD 2000HUB modem
•DTE – E1 : 2.048 Mbps G.703 interface of the MD2703 modem
•DTE – T1 : 1.544 Mbps G.703 interface of the MD20T1 modem
•DTE - J64 : 64 Kbps G.703 interface of the MD 2064 modems
•Alarm relay
Desktop MD 2000:
The power switch located at the rear of the equipment is the 5VDC-switching element. To totally disconnect the equipment from the
supply source we recommend you disconnect the power cord from the wall outlet. This plug must be installed close to the equipment
and provide easy access.
In order to comply with the safety regulations, it is imperative to use the accessories (power supply and cables) provided with the
equipment. When access to the inside of the modem is necessary, it is imperative to disconnect the power cord from the unit - only CXR
maintenance qualified person are allowed to open the enclosure.
Rack mountable card MD 2000 XRF:
The power switch located on the rear of the chassis is the only switching element, thus it must be fully accessible. The connection to the
voltage source is achieved through the cable equipped with a male-grounded plug. Remove the card from the chassis when
maintenance or servicing is required.
For safety reasons, only any component access of the equipment, and particularly opening the desktop enclosure, must be carried out
by maintenance person qualified by CXR.
The equipment must imperatively be returned to CXR in any case of anomaly, fall, loss of performance, water exposure, power supply
damage, …
Environment
The MD 2000 is designed for commercial or light industrial use within the following environmental conditions:
•Storage Temperature 0 to 70 °C
•Operating Temperature: 0 to 45 °C
•Humidity: 0 to 90% without condensation
•Class: IP40
•Flammability: UL94-V0
•Equipment must not be exposed to excessive solar radiation .
•Equipment must not be in contact with water. It must not be used near a water reserve or in a wet location.
Use
The MD2000 modem is designed to be used in a point-to-point mode when connected to a 2 wire dedicated metallic line. Two modems
MD2000 are required to establish a link. No guarantee is given as to compatibility with equipment from different suppliers.
•Modulation : CAP – Carrierless Amplitude and Phase modulation
•Line rate : 144 Kbps, 272 Kbps, 400 Kbps, 528 Kbps, 784 Kbps, 1.040 Mbps, 1.552 Mbps, 2.064 Mbps, 2.320 Mbps, 4.640 Mbps
•Useful spectrum : from 110 to 600 kHz
•Framed mode Nx64 : from 64 Kbps to 2.048 Mbps
•Clear channel mode: 2.320 and 4.640 Mbps
•Ethernet bridge and 8 port HUB:
¾Ethernet 802.3
¾Frame buffer memory : 256
¾Mac address memory : 10.000
•E1 G.703-G.704 interface :
¾rate : 2.048 Mbps
¾coding : HDB3
¾framing : 32 time slots – G.704 compatible
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Instruction Manual MD 2000
¾receiver sensitivity : -40 dB
•T1 interface :
¾rate : 1.544 Mbps
¾coding : B8ZS or AMI
¾framing : 24 time slots with F bit – G.704 compatible
¾line build outs : DSX-1 and CSU
¾receiver sensitivity : -36 dB
1 Introduction
The MD 2000 is an mDSL modem (Multi-Rate Digital Subscriber Line) which provides multi rate symmetrical data transmission over a 2
wire dedicated metallic line at speeds up to 2.048Mbps, in increment of 64 Kbps in framed mode or 2.32 or even 4.64 Mbps in clear
channel mode. One of the main advantages of mDSL modems compared to earlier technology is the fact that the line transmission
speed can be adapted either manually or automatically to the line conditions and line length, to provide optimum performance. The CAP
modulation also provides optimum transmission performances such as:
Narrow spectrum limits cross-talk with adjacent pairs - 500 kHz at 2.32 Mbps
High rate up-to 4.64 Mbps
On-line multi rate to meet the best rate according to the line characteristics
Transmission conforms to ETSI ETS 1001 135 and ITU-T G.991.1 standards
Transmission with echo canceller for better performance when noise or cross-talk on line
Super-frame up-to 2.048Mbps optimizes the synchronization and allows error rate statistics and Nx64 Kbps rate adaptation
1.1 DTE Interfaces
The MD 2000 can be equipped with different types of interfaces:
V.11 and
V.35
interface :
for synchronous data transmission at speeds up-to 4.64Mbps. Clocks can be configured either as internal, external or
receive recovery modes. Most output signals may be forced or activated when the connection is established.
V28 -
RS232 : this interface carries synchronous links at 64Kbps or 128Kbps, or asynchronous data at 300 to 115,200 bps by
synchronous over sampling.
E1 G.703-
G.704
interface :
for E1 transmission. The link can be established at a rate of 2.048 Mbps for the transmission of full 32 timeslot E1
signal, or at a lower rate in increments of 64 Kbps for fractional E1 mode, the G..704 interface at 2.048 Mbps being
reconfigured at the end of the link.
T1 G.704
interface : for T1 transmission. The link can be established at a rate of 1.544 Mbps for the transmission of full 24 timeslot T1
signal, or at a lower rate in increments of 64 Kbps for fractional T1 mode, the G.704 interface at 1.544 Mbps being
reconfigured at the end of the link.
J64 64
Kbps-
G.703
interface :
for a single 64 Kbps channel transmission. The remote modem can be either an E1 / G.703-G.704 or a V.35 - X.21
model set up for 64 Kbps mode.
10BT and
HUB
interface :
the built-in Ethernet bridge filters the frames in accordance with their destination MAC address. Only frames with non-
local MAC addresses are transmitted to the remote modem. The bridge can memorize up to 10.000 local addresses
and process 15.000 frames per second. The HUB version provides 8 Ethernet ports and thus avoids the addition of
an external mini-hub for the end termination.
1.2 Conditioning
The MD 2000 can meet all integration requirements either as a desktop or rack-mount unit with different power-supply configurations:
External
adapter provides a regulated 5 VDC from the mains 110/230 VAC.
Internal
power
supply
the modem includes a 110/230 VAC - 5 VDC power converter which connects directly to the power outlet via the
supplied power cord.
Internal 48
VDC
converter
the modem includes a 48 VDC power converter, which can be connected to a 48VDC supply commonly available in
telecom centers.
Rack-
mountable
card
the 5 VDC required by the modem is supplied by the rack in which the card is inserted. The AMS 4 and AMS 16
chassis can be powered from 110/230 VAC or 48 VDC depending on the type of power module installed with provision
for full redundancy.
MD 2000 - Page 7

Instruction Manual MD 2000
1.3 Installation and initial set-up
The MD 2000 is easy to install. One modem must be configured as NTU (Network Termination Unit) at one end of the line, and the other
end as LTU (Line Termination Unit). The clock signals can be independently configured.
The MD 2000 offers an automatic connection mode, which probes the line to connect at the best possible rate. This automatic mode can
be disabled in order to force a pre-determined rate; in a Telecommunication provider/Subscriber environment, the rate may be set at the
central site and the subscriber modem will automatically adjust itself to the same rate without user intervention. This automatic mode is
activated by the following configuration
¾The LTU Network modem – disable lower rate fall back : %H0 parameter
¾NTU Line modem – automatic setting : @U0 parameter
1.4 Configuration
The MD 2000 is configured via the serial control port located on the rear of the equipment (RJ-45).
In VT100 emulation mode, the configuration is menu driven with on-line help facilities. Only a few keyboard strokes will be required to
set and save the modem parameters. These menus also initiate analog and digital test loops and display a status report as well as bit
error rate statistics.
Alternatively the modem can be configured using an AT command set which provides access to all modem parameters.
The MD 2000 PR card can also be configured by the CFIP controller card of the AMS16 chassis though its local VT100 mode or TCP-IP
Telnet and SNMP management protocols.
1.5 Factory Configurations
The MD 2000 includes two factory configurations: one NTU mode and one LTU mode, which allow for faster and easier installation since
you do not have to configure the modem via the control port. The NTU or LTU configuration is easily selected by pressing the front panel
push button during the power- up sequence on the LED front panel version. See chapter 3.
1.6 Alarm relays
The MD2000 is equipped with an alarm relay whose contacts are available on the rear of the equipment via the stereo jack. This relay is
activated in the following conditions:
¾In case of power loss
¾In case of error during the power up self test
¾In case of a carrier loss during a time period longer than a preset threshold
¾By an AT command.
1.7 G.703/G.704 Interface
The E1 -T1 / G.704 interface operates at a constant rate of 2.048 Mbps (E1) or
1.544 Mbps (T1) with 32 or 24 timeslots (framed mode). However, if this rate can not be reached under some line conditions, then only a
number (N) of timeslots can be transmitted in Nx64 mode (fractional E1 / T1 mode) with the remaining time slots being discarded.
The first timeslot (TS0) of the E1 interface can be either transmitted transparently or controlled locally by setting TS1 as the start
timeslot. The MD2703 can manage the CRC4 in this mode.
The MD20T1 can manage the CRC6.
1.8 Application Examples
The MD2000 can be used for a wide variety of applications such as:
Local Area Network interconnection – LAN to LAN with filtering bridge
High rate data transmission at 4.64 Mbps in clear channel mode
G.703-G.704 PABX interconnection
E1-G.704-PRI mode subscriber to network connection
T1 / DSX-1 interconnection
Videoconferencing
MD 2000 - Page 8

Instruction Manual MD 2000
2 Installation
2.1 Desktop Modem
2.1.1 Accessories
•One RJ-45-RJ 45 cable and one RJ-45-DB9 converter for the control port
•One RJ11cable for line connection
•External power supply module when applicable (MD2000 XVF version)
•One DB25-DB15 cable if modem is equipped with an X.21-V.11 interface (MD2011 version). This cable is optional and should be
ordered separately (P/N: CA 601 461)
•One DB25-V.35 cable if the modem is equipped with a V.35 interface (MD2035 version) This cable is optional and must be ordered
separately (P/N:CA 601 460)
•One RJ-45-RJ-45 cable for G.703-G.704 interface – (MD2703 and MD20T1 versions)
•This user Manual
2.1.2 Connections
•Connect the modem as per the following drawing. View is from the rear.
•The DTE terminal connector depends on the type of interface:
•A DB25 socket for V28-RS232, X.21-V.11 and V.35 interfaces,
•An RJ-45 socket for 10BT, J64 and E1/T1 G.703 interfaces,
•A multiple RJ-45 socket for the 8 port hub interface.
OFF ON
110/230Vac
LINE CONTROL
Back View
TERMINAL
SELVLeased
line access
SELV
V24
DTE
SELVAccess*
*SELV = Safety low voltage
(**) 110/230VAC / 5VDC Wallmount power supply or 230VAC or 48 VDC cable as applicable
•For safety reasons it is imperative to use the accessories (power adapter and cable) provided with the modem.
2.1.3 Powering
The power adapter is the only switching device and therefore the power outlet should be located close to the equipment and easily
accessed.
Once the modem has been connected, switch the ON-OFF switch to the « ON » position
2.2 Rack mount Modem
2.2.1 Accessories
•One RJ-45-RJ 45 cable and one RJ-45-DB25 converter for the control port
•One RJ11cable for line connection
•One DB25-DB15 cable if modem is equipped with a X.21-V.11 interface (MD2011 version). This cable is optional and should be
ordered separately (P/N: CA 601 461)
•One DB25-V.35 cable if the modem is equipped with a V.35 interface (MD2035 version) This cable is optional and must be ordered
separately (P/N:CA 601 460)
•One RJ-45-RJ-45 cable for G.703 interface – (MD 2703, MD 20T1, MD 2064 versions)
•This user Manual
MD 2000 - Page 9

Instruction Manual MD 2000
2.2.2 Installation
•Please also refer to the chassis user manual for the modem installation.
•Locate an open slot in the chassis and insert the MD 2000 card.
2.2.3 Connections
•Connect the modem at the rear of the chassis as per the following drawing:
•The DTE terminal connector depends on the type of interface:
•A DB25 socket for V28-RS232, X.21-V.11 and V.35 interfaces,
•An RJ-45 socket for 10BT, J64 and E1/T1 G.703 interfaces.
DTE
SELV* access
Control
V24 port
SELV* access
Leased line
SELV* acces
s
*SELV = Safety Low Voltage
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
SHELF
IN
SHELF
OUT
MODEM
CTL
230V
50HZ
2AMAX
CLASSEI
+10%
-15%
-
48V
+
CGND
SGND
NO
C
NC
SPARE
ALARM
ADMIN
RUEDEL'ORNETTE 28410 ABONDANT
NUMERODESERIE
SERIALNUMBER
AMS16-2
DATEDEFABRICATION
YEAROFMANUFACTURING
FABRIQUEENFRANCE/ MADEINFRANCE
DEVICES
LI
N
E1
-
LI
N
E
2
/L
S
T
E
R
MI
N
A
L
ANDERSON
JACOBSON
10BT
O
I
2.2.4 Powering
•The modem card connects to the chassis power supply when it is fully inserted. The chassis is powered on and off through the rear
panel power switch.
•Screw the modem front panel to the chassis to avoid any accidental power or connection loss
2.3 Automatic Self-Test
Main components are checked by an internal self test when the modem is powered on:
9Program memory
9Data memory
9Non volatile memory
9DSP
The “TEST” indicator on the front panel is turned ON during the test sequence
•the “Test” LED indicator is turned OFF if the test was successful.
•it flashes if an error was detected. The error type is displayed by the ATI7 command. See chapter 15 " Troubleshooting.
MD 2000 - Page 10