Megger BERT-20E1 User manual

M
BERT-20E1
2.048 Mbps Network Analyzer
USER MANUAL
BERT_20E1_6172-871_UG_V02 05/05/2004 8:24 am Page 1

GSAFETY WARNINGS
■Safety isolation to permit connections to signal lines carrying hazardous voltages (including TNV-1, TNV-2 and TNV-3) is not provided. NEVER
connect the BERT 20E1 to such lines.
■This product is intended only for connection to circuits carrying SELV voltages in an indoor environment and where appropriate surge and transient
protection has been fitted. The network and user terminals may be raised to hazardous voltages if this unit is connected to non SELV circuits.
■This instrument should not be used if there are any visible signs of damage to the case or terminal area. In such cases, the instrument should be
returned to a Megger authorised repair and service centre.
2
NOTE
THE INSTRUMENT MUST ONLY BE USED BY SUITABLY TRAINED AND COMPETENT PERSONS.
BERT_20E1_6172-871_UG_V02 05/05/2004 8:24 am Page 2

TS/Channel Frequency & Level
RX Level Measurements
RX Frequency/Clock Slips
PERF – PERFORMANCE RESULTS 15
Unavailable Seconds/Available Seconds
Degraded Minutes/Degraded Minutes Percent
Severely Error Seconds/Severely Error Seconds Percent
Error Seconds/Error Free Seconds
RX Status LEDs
TS/Channel Data Bits & Signaling Bits
AUXILIARY MENU FUNCTIONS 17
00 Monitor Jack Gain
01 Test Length
02 Error Inject Rates
03 User Pattern [1]
04 User Pattern [2]
05 Time of Day
06 Day and Date
PRINTING RESULTS 18
Printouts
PRODUCT SPECIFICATIONS 19
Symbols used on the instrument are:
FCaution: risk of electric shock
GCaution: refer to accompanying notes
cEquipment complies with current EU directives.
CONTENTS
3
GETTING STARTED 5
Software Revision
Supplied Equipment
Handling Precautions
Front Panel Features
Test Modes
Frame Structures
Test Patterns
Line Codes
Auxiliary Functions
Power
Batteries
CONNECTING TO THE NETWORK 10
Connecting to a Protected Monitor Point
Connecting to a Unprotected Monitor Point
SELECTING OPERATING MODES 12
NORM –Normal Mode
AUTO – Automatic Detection Mode
Fx56 – Fractional E1 (Nx56) Mode
Fx64 – Fractional E1 (Nx64) Mode
D/I – Half Duplex Drop and Insert
TONE – Tone Insertion Mode
LLB – Local Loop Back
TLB – Test Loop Back
DLAY – Round Trip Loop Delay Measurement Mode
CO64 – Co-directional Interface 64 kbps
VIEWING TEST RESULTS 14
NORM – Normal List of BER and Non-BER Results
CRC Errors/CRC Error Rate
FAS Bit Errors/E Bit Errors
Bipolar Violation Errors & BPV Rate
Bit Errors & Bit Error Rate
Error Free Seconds & Percent Error Free Seconds
Error Seconds & Severely Error Seconds
BERT_20E1_6172-871_UG_V02 05/05/2004 8:24 am Page 3

■Frequency and amplitude measurements
■Displays signaling bits and TS data bits
■Monitor voice with internal speaker
■Single channel DTMF digit decode
■Measure clock synchronization problems (bit slips)
■Round trip loop delay measurement
■Performance analysis to ITU-T G.821
Overview
4
The BERT-20E1 test set delivers a powerful hand-held solution for
testing 2.048 Mbps E1 and 64 kbps digital circuits. It combines extensive
BER test functions along with signal quality measurements structured
behind an intuitive user interface. This combination of test capability and
user-friendly ergonomics simplifies installation and maintenance testing,
thus offering faster circuit turn-up and problem resolution. The BERT-
20E1 also provides more than 8 hours measurement operation from a
single charge, making it ideal for one-shift testing particularly in
environments where a convenient power supply may not be available.
Measurement Summary
The BERT-20E1 combines BER test functions along with signal
qualitymeasurement providing the ability to evaluate and troubleshoot 2
Mbps, n x 64 kbps and 64 kbps co-directional circuits.
■Transmits both PRBS and Word test patterns. PRBS: 27-1, 29-1, 211-1,
215-1, 220-1, 223-1 as per ITU-T O.151, O.152, O.153. Word: two 64-bit
user defined patterns, all-ones, all-zeros, 1:1.
■Fractional (Nx56 and Nx64 kbps) BER testing.
■Full 2.048 Mbps BER testing.
■Logic error insert – single and user selectable rate
■BPV error insert – single and user selectable rate
■FAS error insert – single and user selectable rate
■CRC4 error insert – single and user selectable rate
■Single channel insert for BER patterns and analog test tones
■LLB mode – line loop-back mode with error analysis
■TLB mode – test loop-back mode with error analysis
■Displays standard alarm conditions with history LEDs
■Displays major performance parameters
BERT_20E1_6172-871_UG_V02 05/05/2004 8:24 am Page 4

Cleaning Guidelines: To clean the surface of your BERT-20E1, lightly
wipe with a soft cloth that is coated with isopropyl alcohol, ethyl
alcohol, or thichloroethylene solvent. Do not use water, ketone, or
aromatics.
Environmental Conditions: Do not exceed the operating temperature
limits of -20°C to +50°C, -4°F to +122°F (as specified in the technical
specifications section of this manual). Do not store or operate your
BERT-20E1 where it will be exposed to direct sunlight, high
temperatures, or high humidity for extended periods of time.
GETTING STARTED
5
This section is intended to give first-time users a quick overview of the
main features of BERT-20E1. Much of the information is repeated later in
this manual, but in greater detail.
Software Revision
The software and hardware of the BERT-20E1 is displayed in the
opening screen when the unit is initially powered-up.
Supplied Equipment
The BERT-20E1 is supplied with the following items.
■A/C power adapter
■User manual including CD-ROM based E1 basics
■Carrying case
■Rubber boot
Handling Precautions
Shipping and Packaging: The BERT-20E1 is carefully packaged to
prevent damage to the test set during shipment. When you receive your
BERT-20E1, carefully observe the shipping container before the carrier
departs. If the container is damaged, present it to the carrier at this time.
After unpacking your test set, examine it to ensure that it is free of any
visible signs of damage. If the BERT-20E1 was damaged during
shipment, immediately file a claim with the carrier.
Service and Adjustment: The BERT-20E1 contains no user-serviceable
parts. Service or adjustment should only be made by Megger personnel
to ensure that the safety features of the test set are not affected. If you
are experiencing difficulties with your test set, contact Megger at
www.megger.com.
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6
FRONT PANEL FEATURES
PRINTER (and data) output
RX - 75 Ω
TX - 75 Ω
TX output/RX
input 120 Ω
EXT CLOCK IN input
DISPLAYED RESULTS
FORMAT selector
LINE TERMINATION
selector
DISPLAY CONTAST
controls
TS/CHANNEL DATA and
SIGNALLING bits
DISPLAYED RESULTS SCROLL keys
Print on demand
SPEAKER VOLUME controls
BATTERY STAUS indicator
TS/CHANNEL SELECTION keys and
display
Stores test configuration
Recalls test configuration
Selects circuit termination
Injects LOGIC, BPV or FRAME/CRC
errors
Power ON/OFF
d.c input
AUXILLARY MENU FUNCTION SELECTION keys
RECEIVER STATUS
indicators
Clears RECEIVER STATUS
history
Clears errors and RX Status
and restarts tests
Selects transmitter setup
menu
Selects transmitter clock
source
BERT_20E1_6172-871_UG_V02 05/05/2004 8:24 am Page 6

Frame Structures
7
Test Modes
NORM E1 Norm mode
AUTO Automatic detection mode
Fx56 Fractional E1 (Nx56) mode
Fx64 Fractional E1 (Nx64) mode
D/I Half duplex drop and insert mode
TONE Tone insert mode
LLB Local loop back mode
TLB Test loop back mode
DLAY Round trip loop delay
measurement
CO64 Co-directional 64kbps mode
NONE No Framing
P31 No multiframing
P31C CRC multiframing
No TS-16 multiframing
P30 TS-16 multiframing
No CRC multiframing
P30C TS-16 multiframing and CRC
multiframing
BERT_20E1_6172-871_UG_V02 05/05/2004 8:24 am Page 7

Line CodesTest Patterns
8
USER1 User defined test
Pattern up to 64 bits.
USER2 User defined test
Pattern up to 64 bits.
27-1 as per ITU-T O.151,
O.152, O.153.
29-1 as per ITU-T O.151,
O.152, O.153.
211-1 as per ITU-T O.151,
O.152, O.153.
215-1 as per ITU-T O.151,
O.152, O.153.
220-1 as per ITU-T O.151,
O.152, O.153.
223-1 as per ITU-T O.151,
O.152, O.153.
1:1 Alternating ones and zeros
pattern
ZEROS All zeros pattern
ONES All ones pattern
AMI Alternate mark inversion
HDB3 High density bipolar 3
BERT_20E1_6172-871_UG_V02 05/05/2004 8:24 am Page 8

Auxiliary Functions Power
The BERT-20E1 is primarily powered by five, rechargeable, nickel metal
hydride (NiMH) batteries. An auxiliary power connector (which is
provided with the BERT-20E1) is available for use with an AC/DC power
adapter. The ON/OFF switch is located on the front panel of the BERT-
20E1. Battery status is monitored and displayed with the BATTERY
STATUS indicator, located on the front panel.
Batteries
The BERT-20E1 contains five, 1.2V, 4Ahr. NiMH, rechargeable batteries.
These batteries will provide approximately eight hours of continuous
operation (when fully charged). The charging voltage is 9 VDC and the
rated current is 1.4 A. A regulated 9 VDC, 1.5 A power adapter may be
used for charging. Recharge time is typically 4-6 hours depending on
how deeply the batteries have been discharged.
The BERT-20E1 batteries are not serviceable. To recharge the batteries,
connect the 9 VDC power source to the DC jack located on the front
panel. The test set will charge during operation, but it is recommended
that the unit is turned off when not in use to fully charge the unit. To
determine the charging status, observe the red and green LEDs located
on the lower front panel of the BERT-20E1. The red LED illuminates
when the battery is in the charging state. The green LED illuminates
when the battery is in maintenance charge. If both LEDs are off, the
batteries are either absent from the test set or do not fall within the
proper temperature range to charge the batteries. If both LEDs are
illuminated, the battery is not properly charging and you must return the
BERT-20E1 to Megger for repair.
9
00 MONITOR JACK GAIN (None,
12dB, 30dB)
01 TEST LENGTH
02 ERROR INJECT RATES
03 USER PATTERN [1]
04 USER PATTERN [2]
05 TIME OF DAY SETTING
06 DAY AND DATE SETTING
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10
The receiver interface termination can be:
BERT-20E1 provides 75 Ωunbalanced and 120 Ωbalanced transmit and
receive interfaces located at the top of the instrument.
75 ΩRECEIVE Receiver input interface. Allows the connection of
75 Ωunbalanced data signals.
75 ΩTRANSMIT Transmitter output interface. Provides 75 Ω
unbalanced data output.
120 ΩRECEIVE Receiver input interface. Allows the connection of
120 Ωbalanced data signals.
120 ΩTRANSMIT Transmitter output interface. Provides 120 Ω
balanced data output.
EXT CLOCK IN Allows connection of a 75 Ωtiming reference as per
ITU-T G.811. The reference format may be either
clock or another E1 data data source
CONNECTING TO THE NETWORK
Terminated 0dB Gain.
Monitor 0dB Gain.
Monitor 12dB Gain – to
compensate for a low
level signal at
a network equipment
monitor point.
Monitor 30dB Gain – to
compensate for a low
level signal at
a network equipment
monitor point.
Bridged High impedance.
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