Pendulum WM-10 User manual

Wandermeters
WM-10 & WM-11
Users Manual

II
4031 600 10001
Rev. 05 (February 2003)
This manual, in whole or in part, may not be copied without permission.
All product names are trademarks of their respective companies.
© 2000 Pendulum Instruments AB
All rights reserved. Printed in Sweden.

Table of Contents
EC DECLARATION OF CONFORMITY . . I-IV
1 Preface
Introduction ........................1-2
2 Safety Instructions
Introduction ........................2-2
Safety Precautions ..................2-2
Grounding .........................2-3
Power Switch.......................2-3
Disposal of Hazardous Material.........2-3
3 Preparations for Use
Unpacking Instructions ...............3-2
Installation .........................3-2
Orientation and Cooling ...............3-3
Connecting to a PC ..................3-3
Ethernet Connection (WM-11)..........3-4
4 Using the Controls
About This Chapter ..................4-2
Basic Controls ......................4-2
Rear Panel.........................4-6
Presentation Modes..................4-7
5 WanderView
Introduction ........................5-2
Installation .........................5-2
The WanderViewäScreen ............5-3
Graphs in WanderViewä..............5-9
Application Hints ...................5-11
Introduction to ADEV and MADEV .....5-12
6 Performance Check
General Information .................6-2
Preparations .......................6-2
Outputs ...........................6-2
Test of PC Connection ...............6-3
Front Panel Controls .................6-3
7 Preventive Maintenance
Calibration and Adjustment ............7-2
Backup Battery .....................7-2
8 Specifications
Technical Specification ...............8-2
Ordering Information .................8-6
9 Program Commands
Remote Control .....................9-2
Command Reference Guide ...........9-6
10 Index
11 Service
Sales and Service Office .............11-II
Guarantee Statement ...............11-III
III

EC DECLARATION OF CONFORMITY
Number: PQWM11200206
The undersigned, representing the following manufacturer:
Manufacturer: Pendulum Instruments AB
Karlsbodavägen 39, Box 20020
SE-161 02 Bromma, Sweden
Representative: Kali Rahman
Function: Quality Manager
herewith declares that the product:
Product Identification:
Product: Wandermeter
Brand: Pendulum
Model: WM-10, WM-11
Version: All models
Additional Information:
is in conformance with the EC Directive 89/336/EEC based on test results using harmonized
standards in accordance with Article 10(1) of the directive LVD-73/23/EEC.
Harmonized Standards Used:
Safety: EN 61010-1 (1990) + A1 (1992) + A2 (1995)
Safety Requirements for Electronic Measuring Apparatus.
EMC: EN 61326-1 (1997)
Electrical equipment for measurement, control and laboratory use - EMC
requirements.
EN 55022 (1994) + A1 (1995) + A2 (1997) Class B
Limits and methods for measurement of radio disturbance characteristics
of information technology equipment (ITE).
EN 61000-6-2 (1999)
EMC - generic standards - immunity for industrial environments.
The tests have been performed in a typical configuration.
Place: Bromma Date: 2002-06-03 Signature:
This Conformity is indicated by the symbol , i.e. “Conformité européenne”.
IV

Chapter 1
Preface

Introduction
A wander of the synchronization clock in digi-
tal communication networks can cause severe
transmission problems. Quality control of the
synchronization clock requires monitoring of
wander over a long period (hours or days) using
an ultra-stable clock as reference.
So far measurement of wander has involved
bulky, complex and very expensive instrumen-
tation. To be able to view the wander parame-
ters MTIE and TDEV specified in international
standards, external computers were needed.
Congratulations for choosing the Wandermeter
from Pendulum Instruments. The portable, very
accurate and easy-to-use solution for wander
measurements on sync clocks and encoded data
signals.
Applications
nWM-10
The WM-10 Wandermeter can be used for sev-
eral purposes:
1. Clock quality verification according to stan-
dards (ITU G811-813) for telephone network
operators.
2. Clock quality verification according to ITU
or ETSI standards for leasers of synchroniza-
tion services, e.g. other telephone operators.
3. Troubleshooting in SDH or PDH networks
when a node is suspected not to operate cor-
rectly.
4. Preventive (diagnostic) maintenance of local
exchange stations (SDH or PDH).
5. Troubleshooting in GSM networks that use
the E1 clock for synchronization.
nWM-11
The Wandermeter WM-11 can be used for the
same purposes as the WM-10 (see preceding
paragraph) but has also additional areas of ap-
plication:
1. Troubleshooting in SONET networks when a
node is suspected not to operate correctly.
2. Preventive (diagnostic) maintenance of local
exchange stations (SONET).
Product Key Features
nWM-10
The WM-10 Wandermeter has the following
features:
–Wandermeter for verifying 2.048 MHz
(sync clock) or 2.048 Mbit/s (HDB3 data)
in SDH-network nodes (ITU G811-813).
–Self-contained unit with built-in Rubidium
Reference and graphical display. Can be
left unattended for automatic measure-
ments, without a PC, for diagnostic and
troubleshooting measurements.
–Graphical presentation of TIE, MTIE and
TDEV. Comparison with standard masks.
–Very easy to use.
–Transportable.
–Self-adjusting internal reference when con-
nected to a stable reference, e.g. Cesium or
GPS-controlled Rubidium frequency stan-
dard.
nWM-11
The WM-11 Wandermeter can perform the
same tasks as the WM-10 (see preceding para-
graph) but has also additional features:
–Wandermeter for verifying 1.544 MHz
(sync clock) or 1.544 Mbit/s (HDB3 data)
in SONET network nodes.
1-2 Introduction
Preface

–Wandermeter for other customary frequen-
cies in data, video and frequency distribu-
tion systems:
4 kHz, 8 kHz, 15.750 kHz (NTSC),
15.625 kHz (PAL), 64 kbit/s, 5 MHz,
10 MHz, 27 MHz, 34 Mbit/s, 45 Mbit/s,
52 Mbit/s
–Ethernet interface for remote control over
Internet.
–48 V DC power supply as backup
Working Principle
The Pendulum WM-10/WM-11 Wandermeter
is built in an EMI-proof metal cabinet and con-
tains a Rubidium Reference and a special Time
Interval Error (TIE) measuring circuitry that
phase-compares the connected clock (or data)
signal with the Rubidium reference. The
Wandermeter communicates with the user via
the front panel keyboard and a graphical dis-
play, and with a PC via an RS-232 port. The
WM-11 has also an Ethernet port.
The Wandermeter operates in two different
modes:
nLocal Mode:
The WM-10/WM-11 Wandermeter can be op-
erated stand-alone. During the measurement,
the TIE curve on the display is continuously up-
dated, showing the performance of the
sync-clock “so far”. This mode is intended for
fully automated diagnostics and/or trouble-
shooting measurement “on-site”, with direct vi-
sual feedback at any time. The sampling rate is
approx. 1 Sa/s. The Wandermeter calculates
and presents the MTIE or TDEV curves after a
completed TIE measurement, and compares
with stored masks.
nRemote Mode
The Wandermeter can be remotely controlled
from a PC, running a PC-SW called
WanderViewä. In this mode the
Wandermeter acts as a sampling front-end and
transfers the TIE values one by one to the PC.
The local display of the Wandermeter is not up-
dated. Sample speed is >30 TIE values/s and
the storage is only limited by the PC, which
means that the fast sample rate can be main-
tained during a 24h period (or longer if re-
quired). The PC-SW calculates and presents the
TIE, MTIE or TDEV curves after a completed
measurement period and compares with stan-
dard masks, but it is also possible to take snap-
shots during a running measurement. This
mode is mainly intended for protocolled verifi-
cation measurements according to ITU or ETSI
standards.
Two additional presentation modes, ADEV and
MADEV, can be used from WanderView. See
introduction on page 5-12.
RS-232 Connection
A PC is connected to the RS-232 port at the rear
of the instrument. A suitable cable should have
female DB9 connectors at both ends and be de-
signed as a “null-modem” cable. Such a cable is
delivered with the instrument.
Ethernet Connection (only WM-11)
After configuration by means of the
WanderView SW over the auxiliary RS-232 in-
terface marked CONFIG IP, the Ethernet inter-
face lets the operator communicate with the
Wandermeter in much the same way as with
any Ethernet node. Remote control and data
logging over the Internet is thus a simple task.
Standard Cat 5 patch cords of good quality with
RJ45 connectors can be used.
Note: There are two types available,
straight-through and cross-wired. The first one
is used when connecting to a wall outlet or a
hub, the second one when connecting directly
to a PC or other controller.
1-3 Introduction
Preface

Easy to Use
A fully automatic signal check informs the user
whether he/she has connected the right signal
from the rack (e.g clock or data signal).
The unit can be left unattended. It stops after set
measuring time and can even delay its measure-
ment start if certain conditions are met. This
function is intended for letting the instrument
warm up properly before a critical measure-
ment. The invoked timer starts automatically on
power-up, so if the desired delay has already
passed when the command is entered, nothing
will happen.
On-line context-sensitive help is available,
making the users manual obsolete in most
cases.
1-4 Introduction
Preface

Chapter 2
Safety Instructions

Introduction
Read this page carefully before you install and
use the instrument.
This instrument has been designed and tested
according to safety Class 1 requirements of IEC
publication EN61010-1 and CSA 22.2 No.231,
and has been supplied in a safe condition. The
user of this instrument must have the required
knowledge of it. This knowledge can be gained
by thoroughly studying this manual.
This instrument is designed to be used by
trained personnel only. Removal of the cover
for repair of the instrument must be done by
qualified personnel who are aware of the haz-
ards involved. There are no user-serviceable
parts inside the instrument.
Safety Precautions
To ensure the correct and safe operation of this
instrument, it is essential that you follow gener-
ally accepted safety procedures in addition to
the safety precautions specified in this manual.
Caution and Warning
Statements
CAUTION: Shows where incorrect
procedures can cause damage to,
or destruction of equipment or
other property.
WARNING: Shows a potential danger
that requires correct procedures
or practices to prevent personal
injury.
Symbols
Shows where the protective ground
terminal is connected inside the instru-
ment. Never remove or loosen this
screw.
Indicates that the operator should con-
sult the manual.
2-2 Introduction
Safety Instructions
Z
Z
Z
...
SAFETY
Figure 2-1 Do not overlook the
safety instructions!

If in Doubt about Safety
Whenever you suspect that it is unsafe to use
the instrument, you must make it inoperative by
doing as follows:
–Disconnect the line cord.
–Clearly mark the instrument to prevent its
further operation.
–Inform your local Pendulum Service Cen-
ter..
For example, the instrument is likely to be un-
safe if it is visibly damaged.
Grounding
Whenever an instrument is connected
to the line voltage, a grounding fault
will make it potentially dangerous. Be-
fore connecting any unit to the power line, you
must make sure that the protective ground func-
tions correctly. Only then can a unit be con-
nected to the power line and only by using a
three-wire line cord. No other method of
grounding is permitted. Extension cords must
always have a protective ground conductor.
WARNING: If a unit is moved from a
cold to a warm environment, con-
densation may cause a shock
hazard. Ensure, therefore, that the
grounding requirements are
strictly met.
WARNING: Never interrupt the
grounding cord. Any interruption
of the protective ground connec-
tion inside or outside the
instrument or disconnection of the
protective ground terminal is likely
to make the instrument danger-
ous.
Power Switch
This instrument is equipped with a secondary
power switch. It disconnects the main
power-consuming circuits on the secondary
side of the power supply but leaves the Rubid-
ium oscillator active in order to retain its
long-term characteristics. Line voltage is al-
ways present on the primary side.
WARNING: Always consider the in-
strument active as soon as it is
connected to the primary ac power
source with a power cord.
Disposal of
Hazardous Material
This instrument usesa3Vlithium cell to power
a backup RAM. It is placed in a holder and can
easily be exchanged.
WARNING: Disposal of lithium cells
requires special attention. Do not
expose them to heat or put them
under excessive pressure. These
measures may cause the cells to
explode. Make sure they are recy-
cled according to local
regulations.
2-3 Grounding
Safety Instructions

This page is intentionally left blank.
2-4 Disposal of Hazardous Material
Safety Instructions

Chapter 3
Preparations for Use

Unpacking
Instructions
Check that the shipment is complete and that no
damage has occurred during transportation. If
the contents are incomplete or damaged, file a
claim with the carrier immediately. Also notify
your local Pendulum sales or service office in
case repair or replacement may be required.
Check List
The shipment should contain the following:
–The Wandermeter.
–Line cord.
–WM-11 only: cable connector matching the
-48 V DC rear panel connector.
–WanderViewäprogram disks.
–This Users Manual.
–RS-232 null-modem cable (DB9).
–120/75 WBaluns.
–If you ordered option 35, it should already
be installed. See “Identification” below.
–Other options you ordered, e.g. Transport
case (option 27W) are shipped in separate
boxes.
–Certificate of Calibration.
Identification
Options installed inside the cover are identified
on the rear panel according to the list below.
Option 35 (Only WM-10): 2 BNC-connectors
mounted in the area designated “optional 2.048
MHz output”.
Installation
AC Supply Voltage
nSetting
The instrument may be connected to any AC
supply with a voltage rating of 90 to 264 Vrms,
47 to 63 Hz. The instrument automatically ad-
justs itself to the line voltage.
nFuse
The high-voltage AC Power Supply is pro-
tected by a 2A/250V internal fuse that is used
over the full voltage range. In case of failure,
the instrument must be returned to a Pendulum
Authorized Service Center. There are no user
serviceable parts in the Power Supply.
CAUTION: If this fuse is blown, it is
likely that the AC power supply is
badly damaged. Do not replace the
fuse. Send the instrument to the
local Pendulum Service Center.
DC Supply Voltage (WM-11)
nSetting
The instrument may be connected to any DC
supply with a voltage rating of 38 to 72 V and
capable of delivering up to 60 W. The instru-
ment automatically adjusts itself to the terminal
voltage of the power source and is protected
against reverse polarization.
nFuse
The low-voltage DC power supply is protected
by a 2A/250V internal fuse that is placed inside
the instrument on the separate DC power sup-
ply PCB. It is used over the full voltage range.
3-2 Unpacking Instructions
Preparations for Use

CAUTION: If this fuse is blown, it is
likely that the DC power supply is
badly damaged. Do not replace the
fuse. Send the instrument to the
local Pendulum Service Center.
nAC Power Supply Backup
If both AC and DC power are connected at the
same time, the AC supply will take precedence.
In this case the combined supply units will in
fact work as a UPS (Uninterruptible Power
Supply), however without the ability to reload
an external battery used as a DC source.
Orientation and
Cooling
The instrument is intended to be operated on a
bench. Leave 5 centimeters (2 inches) of space
around the instrument.
Fold-Down Support
For bench-top use, a fold-down support (2 plas-
tic “feet”) is available for use underneath the in-
strument.
Carrying Handles
Two side handles can be used to carry the in-
strument.
Connecting to a PC
A PC can be connected to the RS-232 port at the
rear of the instrument. A suitable cable should
have female DB9 connectors at both ends and
be designed as a “null-modem” cable. Such a
cable is enclosed with the shipment.
3-3 Orientation and Cooling
Preparations for Use
75W Max12 Vrms
75 Max12 VrmsW
WM-10 Wandermeter - E1
EXT. REF. IN 10MHz
Max12Vrms
CLOCK/DATA IN A
CLOCK/DATA IN B
STAND
BY
ON TIE MTIE TDEV
SIGNAL
CHECK
SETUP
START
STOP
SAVE
RECALL
USER
OPTIONS
EXIT SELECT
MENU
KEYS
i
Figure 3-1 Fold-down support for
comfortable bench-top
use.
75W Max12 Vrms
75 Max12 VrmsW
WM-10 Wandermeter - E1
EXT. REF. IN 10MHz
Max12Vrms
CLOCK/DATA IN A
CLOCK/DATA IN B
STAND
BY
ON TIE MTIE TDEV
SIGNAL
CHECK
SETUP
START
STOP
SAVE
RECALL
USER
OPTIONS
EXIT SELECT
MENU
KEYS
i
Figure 3-2 Use the handles to carry
the wandermeter.
Figure 3-3 Connecting to a PC

Ethernet
Connection
(WM-11)
After configuration by means of the
WanderViewÔSW over the dedicated RS-232
port, the 10Base-T Ethernet interface lets the
operator communicate with the Wandermeter
in much the same way as with any Ethernet
node. Remote control and data logging over the
Internet is thus a simple task.
Standard Cat 5 patch cords of good quality with
RJ45 connectors can be used.
Note: There are two types available,
straight-through and cross-wired. The first one
is used when connecting to a wall outlet or a
hub, the second one when connecting directly
to a PC or other controller.
3-4 Ethernet Connection (WM-11)
Preparations for Use

Chapter 4
Using the Controls

About This Chapter
This chapter gives you a quick introduction to
all the controls of the instrument, the design of
the user interface, and front panel text. For the
occasional user, the information in this chapter
is often sufficient to solve a measurement prob-
lem.
Basic Controls
ON/STANDBY [1]
Press ON to switch on and STANDBY to
switch off the Wandermeter. In the Stand-by
mode, power is maintained for the internal Ru-
bidium timebase, as long as the mains cord is
connected to the mains outlet.
TIE [2]
TIE = Time Interval Error. This is the default
presentation mode, and is selected when the
TIE key is pressed.
TIE is the basic measurement performed by the
Wandermeter, and the TIE raw data is the input
to the MTIE and TDEV processed presentation
modes. During a TIE measurement in Local
Mode, the graphical display is continuously up-
dated. When a TIE measurement is in progress,
the other presentation modes MTIE and TDEV
are not accessible.
After a completed TIE measurement, also the
other presentation modes can be selected.
Note that the default X-scale of the TIE graph is
fixed if a fixed measuring time is selected. E.g.
The X-scale is 0 to 10 000 s for a 2h
measurement time (7200 s) and 0 to 100 000
for a 24h measurement time (86400 s). You can
also set the scale manually to zoom in on a par-
ticular part of the graph, even during a measure-
ment.
The X-scale changes automatically to the cur-
rently elapsed time, when continuous measur-
ing is selected. The default mode for the Y-scale
(TIE) is AUTO, but it is also possible to select
MAN (manual), even during a measurement.
4-2 About This Chapter
Using the Controls
12346711
58910

MTIE [3]
MTIE = Maximum Time Interval Error. This
presentation mode is the calculated max. differ-
ence between any 2 TIE-values for various ob-
servation intervals (t). The MTIE is calculated
according to ETSI standards.
If test mode PRC (ETSI), SSU (ETSI),
SEC (ETSI), SSU-L (ETSI), SEC-L (ETSI) or
any of the “User-Defined” test modes is se-
lected, the corresponding limit masks are also
displayed in the graph. If Test Mode is set to
“None”, no limit masks are displayed. MTIE is
also calculated in Measurement Mode “Differ-
ential”.
MTIE can only be selected after a completed
TIE measurement (only then all data is avail-
able for the MTIE processing). After a com-
pleted TIE measurement, you can toggle be-
tween the different test modes (SETUP menu)
to display various limit masks for comparison
with different standards.
The X-scale (”tau”) is always fixed. The
Y-scale (MTIE) is automatic for test mode
PRC (ETSI), SSU (ETSI), SEC (ETSI),
SSU-L (ETSI), SEC-L (ETSI), and automatic
for “None” and “User-Defined”.
TDEV [4]
TDEV = Time DEViation. This presentation
mode presents the TDEV of the input signal,
calculated according to ETSI-standards.
If test mode PRC (ETSI), SSU (ETSI),
SEC (ETSI), SSU-L (ETSI), SEC-L (ETSI) or
any of the “User-Defined” test modes is se-
lected, the corresponding limit masks are also
displayed in the graph. If test mode is set to
“None”, no limit masks are displayed. TDEV is
also calculated in Measurement Mode “Differ-
ential”.
TDEV can only be selected after a completed
TIE measurement (only then all data is avail-
able for the TDEV processing).
After a completed TIE measurement, you can
toggle between the different test modes
(SETUP menu) to display various limit masks
for comparison with different standards.
4-3 Basic Controls
Using the Controls
12 13
14 15 16 17 18
19

The X-scale (”tau”) is always fixed. The
Y-scale (TDEV) is automatic for test mode
PRC (ETSI), SSU (ETSI), SEC (ETSI),
SSU-L (ETSI), SEC-L (ETSI), and automatic
for “None” and “User-Defined”.
INFO [5]
INFO gives an on-line help for the currently
used function.
SAVE/RECALL [6]
Here you can save up to five measurement set-
ups, three screen plots and one TIE data array
(up to 16k samples). The data array can be sent
to a PC.
USER OPTIONS [7]
Here you find some common settings that do
not affect the current measurement.
–Display contrast /viewing angle
–Choice of external/internal reference
–RS-232 settings (baudrate)
–Self-tests
–Calibration of internal Rubidium timebase
–Choice of output frequency (WM-11)
SIGNAL CHECK [8]
The Wandermeter makes a test measurement of
the signal to verify that the user has connected
the correct signal for the wander measurement.
Different signal characteristics like frequency,
pulse width, Vmax, Vmin, Vp-p and signal type
are measured and displayed in an info-box win-
dow on screen.
In the signal type field, clock signals are recog-
nized by “kHz” or “MHz” after the frequency,
whereas data signals have “kbit/s” or “Mbit/s”
instead.
SETUP [9]
nTest Mode
This setting determines which limit masks are
to be displayed in the MTIE and TDEV graphs,
e.g. PRC (ETSI), SSU (ETSI) and SEC (ETSI)
for the 2.048 Mbit/s signal. The PRC (ETSI) is
the most demanding and the SEC (ETSI) is the
least demanding specification in this example.
“None” mode gives no limit mask.
“User-Defined” mode means that user specific
limit masks are displayed. These are defined in
the WanderViewäSW and loaded into the in-
strument.
nMeasuring Mode
“Absolute” means that the TIE measurement
shows the phase difference between a signal
connected to CLOCK/DATA IN A and either
the built-in rubidium reference or an external
10 MHz reference clock connected to EXT.
REF IN 10 MHz.
“Differential” means that the TIE measurement
shows the relative phase difference between
two signals connected to CLOCK/DATA IN A
and CLOCK/DATA IN B. One example is to
compare the sync clock into a network element
with the regenerated sync clock out of the net-
work element.
nSignal Types
The connected signal can be either symmetri-
cal, unipolar (e.g. 2.048 MHz clock) or unsym-
metrical, bipolar, (e.g. HDB3 or AMI coded
data). The SIGNAL CHECK reveals what type
of signal is connected, and does also a
pre-setting of the Signal Type selection. See the
specifications in Chapter 8 for a summary of the
signal types that WM-10 resp. WM-11 can ac-
cept.
4-4 Basic Controls
Using the Controls