AT2500HM - VeEX Inc.
USER MANUAL
AT2500HM
Series Analyzer
Please direct all questions to your local VeEX Sales Office, Representative, or Distributor. Or, contact VeEX technical support at
www.veexinc.com. Copyright 2014 VeEX Incorporated. All rights reserved.
No part of this user manual may be reproduced, translated into a foreign language, or be transmitted electronically without prior
agreement and written consent of VeEX Incorporated as governed by International copyright laws. Information contained in this
manual is provided “as is” and is subject to change without notice. Trademarks of VeEX Incorporated have been identified where
applicable, however the absence of such identification does not affect the legal status of any trademark.
AT2500 R Series Analyzer Manual MMD-22428-201 Rev. A00
Page 1 of 208
Disclaimer
Information in this document is subject to change without notice and does not represent a
commitment on the part of VeEX, Inc. The software and/or hardware described in this
document are furnished under a license agreement or nondisclosure agreement. The software
may be used or copied only in accordance with the terms of the agreement. It is against
the law to copy the software on any medium except as specifically allowed in the license or
nondisclosure agreement. The purchaser may make one copy of the software for backup
purposes. No part of this manual and/or hardware may be reproduced or transmitted in any
form or by any means, electronic or mechanical, including photocopying, recording, or
information storage and retrieval system, for any purpose other than the purchaser’s personal
use, without the express written permission of VeEX Inc.
Throughout this book, trademarked names are used in an editorial manner only and to the
benefit of the trademark owner, with no intention of infringement of the trademark. Where such
designations appear in this book, they have been printed with initial capital letters.
VeEX, the VeEX logo, are registered trademarks of VeEX, INC.
All other trademarks, copyrights, logos, brand names, etc. mentioned herein are the property of
their respective owners.
Copyright 2014 VeEX, Inc. All rights reserved.
Disclaimer: Contents subject to change without notice.
i
CONTENTS
Chapter 1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
Chapter 2
2.1
2.2
2.3
2.4
Chapter 3
3.1
3.2
3.3
3.4
Chapter 4
INTRODUCTION
1-1
Welcome .......................................................................................... 1-1
Safety Requirements ...................................................................... 1-1
Symbols and Terms........................................................................ 1-2
Model Designations for AT2500HM Series ................................... 1-2
Standard Measurement and Hardware Features ......................... 1-3
Available Options for AT2500HM Series ...................................... 1-4
1.6.1
Software Options................................................................ 1-4
1.6.2
Warranty and Calibration Options ...................................... 1-4
1.6.3
Accessories........................................................................ 1-4
Warranty Information ..................................................................... 1-4
GETTING STARTED
2-1
Receiving and Unpacking .............................................................. 2-1
Physical Location ........................................................................... 2-1
Electrical Connections ................................................................... 2-1
Initial Verification ............................................................................ 2-2
UNDERSTANDING THE AT2500HM
3-1
Automatic Calibration .................................................................... 3-1
AT2500HM Online Help .................................................................. 3-1
AT2500HM User Interface .............................................................. 3-2
3.3.1
Front Panel......................................................................... 3-2
3.3.2
Rear Panel ......................................................................... 3-3
3.3.3
Keyboard Shortcut Keys .................................................... 3-5
Main Menu Software Functions ..................................................... 3-6
3.4.1
Standard Functions and Icons ........................................... 3-7
BASIC AT2500HM FUNCTIONS
4-1
4.1
Default Instrument Settings ........................................................... 4-1
4.2
Storing and Recalling Measurement Records or Instrument
Settings ....................................................................................................... 4-1
4.2.1
Storing Measurement Records .......................................... 4-1
4.2.2
Storing Settings.................................................................. 4-2
4.2.3
Recalling Stored Records .................................................. 4-2
4.2.4
Recalling Stored Settings................................................... 4-3
4.2.5
Superimposing a Record on a Live Trace.......................... 4-4
4.2.6
Freezing a Live Trace ........................................................ 4-4
4.2.7
Erasing Records and Settings............................................ 4-5
Printing Reports and Screens ....................................................... 4-5
4.3
4.3.1
Setting up the Printer ......................................................... 4-6
4.3.2
Printing a Screen................................................................ 4-6
4.3.3
Printing Multiple Records ................................................... 4-7
4.4
Data Communications .................................................................... 4-7
4.4.1
Connecting the AT2500HM to a LAN ................................. 4-7
4.4.2
Connecting a PC directly to the AT2500HM .................... 4-10
ii
Contents
4.5
Chapter 5
5.1
5.2
5.3
Chapter 6
6.1
6.2
6.3
6.4
6.5
Chapter 7
7.1
7.2
Chapter 8
8.1
8.2
4.4.3
4.4.4
4.4.5
4.4.6
4.4.7
Setting
4.5.1
4.5.2
4.5.3
4.5.4
4.5.5
Configuring the AT2500HM Remote Mode ...................... 4-11
Upgrading Firmware ........................................................ 4-12
Transferring AT2500HM User Files with WinCom II ........ 4-12
Using WinRemote with the AT2500HM ........................... 4-14
Using WinQAM with the AT2500HM ................................ 4-15
up the AT2500HM Preferences ....................................... 4-16
Choosing General Operating Parameters........................ 4-17
Defining Custom Screen Colors....................................... 4-19
Setting up a Channel Plan ............................................... 4-20
Setting up Remote Switches ............................................ 4-25
Activating the NTSC Output ............................................. 4-25
USING THE SPECTRUM ANALYZER FUNCTIONS
5-1
Spectrum Analyzer Menus............................................................. 5-1
Spectrum Analyzer Instrument Settings ...................................... 5-2
5.2.1
Tuning to a Frequency ....................................................... 5-2
5.2.2
Using the Filters ................................................................. 5-2
5.2.3
Setting the Span ................................................................ 5-3
5.2.4
Setting the Resolution Bandwidth, Sweep Time and Video
Bandwidth ......................................................................................... 5-4
5.2.5
Setting the Amplitude ......................................................... 5-7
5.2.6
Multiple Trace Display........................................................ 5-7
5.2.7
Using the Markers (Vertical, Horizontal, and Tilt) .............. 5-9
5.2.8
Selecting the Sweep Method ........................................... 5-13
Using the Frequency Counter ..................................................... 5-13
CATVPAK - AUTOMATED CATV MEASUREMENTS
6-1
Digital Channel Power.................................................................... 6-1
Frequencies and Levels ................................................................. 6-2
6.2.1
TV Channel Mode .............................................................. 6-2
6.2.2
Multi-carrier Mode .............................................................. 6-3
AUTOTEST ........................................................................ 6-4
6.2.3
Distortion Measurements............................................................... 6-5
6.3.1
Hum Modulation Measurement .......................................... 6-5
6.3.2
CCN, CSO and CTB measurements ................................. 6-7
In-Channel Frequency Response ................................................ 6-10
Depth of Modulation ..................................................................... 6-11
TIME DOMAIN MEASUREMENTS
Setting
Setting
7.2.1
7.2.2
7.2.3
up the Display .................................................................... 7-1
up the Time and Trigger Functions ................................. 7-2
Resolution Bandwidth, Horizontal Time and Video Bandwidth7-2
Triggering on a Signal ........................................................ 7-3
Zooming in on a Signal ...................................................... 7-4
QAM 16/64/256 DIGITAL MEASUREMENTS
Setting
Testing
8.2.1
8.2.2
7-1
8-1
up the QAM analyzer ......................................................... 8-1
QAM signal quality............................................................ 8-3
Pre and Post Bit Error Rate (BER)..................................... 8-3
Modulation Error Ratio (MER)............................................ 8-4
Contents
8.3
8.4
8.5
8.6
Chapter 9
9.1
9.2
9.3
Chapter 10
10.1
10.2
10.3
Chapter 11
11.1
11.2
Chapter 12
iii
8.2.3
Estimated Noise Margin (ENM).......................................... 8-4
8.2.4
Error Vector Magnitude (EVM) ........................................... 8-4
Constellation Display ..................................................................... 8-4
8.3.1
Zoom Mode ........................................................................ 8-5
8.3.2
Symbol Display Settings .................................................... 8-6
Statistical Graph Display ............................................................... 8-6
Adaptive Equalizer Display ............................................................ 8-7
8.5.1
Frequency Response Display ............................................ 8-8
8.5.2
Group Delay Response...................................................... 8-9
8.5.3
QAM Normalization ............................................................ 8-9
QAM Impairment Analysis (QIA) Display.................................... 8-10
VeEX SERVICE AND SUPPORT
9-1
AT2500HM Maintenance................................................................. 9-1
9.1.1
RF Connector Replacement............................................... 9-1
Technical support ........................................................................... 9-1
Returning Equipment to VeEX................................................... 9-1
SPECIFICATIONS
10-1
AT2500HM Specifications ............................................................ 10-1
10.1.1 Frequency ........................................................................ 10-1
10.1.2 Spans ............................................................................... 10-1
10.1.3 Sweep Time ..................................................................... 10-1
10.1.4 Resolution Bandwidth ...................................................... 10-1
10.1.5 Video Bandwidth .............................................................. 10-2
10.1.6 Amplitude ......................................................................... 10-2
10.1.7 Internal Band Select Filters .............................................. 10-2
10.1.8 Miscellaneous .................................................................. 10-3
10.1.9 Mechanical and Environmental Specifications ................. 10-3
10.1.10 CATV Measurement Specifications ................................. 10-4
10.1.11 TDM Measurement Option............................................... 10-5
10.1.12 Digital Measurement QAM 16/64/256 Specifications ....... 10-5
10.1.13 Analog Video Measurements ........................................... 10-7
Notes .............................................................................................. 10-7
Compliance documentation......................................................... 10-9
GLOSSARY
11-1
Abbreviations ................................................................................ 11-1
Terms ............................................................................................. 11-2
INDEX
12-1
1-1
Chapter 1
INTRODUCTION
1.1
Welcome
The VeEX AT2500HM series analyzer (models HM, and HMQ,) is a
1.5 GHz, rackmount RF spectrum analyzer with battery backup, designed specifically for
CATV applications. Functions include basic spectrum analysis, automated CATV tools for
daily testing and preventative maintenance, QAM analysis, video demodulation test and
analysis for locating faults or troubleshooting, Ethernet connectivity for real-time remote
control capability, and FCC proof of performance testing.
The AT2500HM series analyzer has a broad input range, high sensitivity and advanced circuit
design characteristics that provide accurate and repeatable measurements in the headend, hub
or in the field. Its front end incorporates a unique filtering capability with high/low pass, band
selectable filters that prevent accidentally overloading the spectrum analyzer.
Testing options include one-button measuring of signal levels, with the appropriate correction
factors for different modulation types, measurement of carrier-to-noise ratio, composite second
and composite third order distortions as well as hum modulation, depth of modulation, time
domain measurements for upstream bursty RF signal validation and QAM digital
measurements such as MER, Pre/Post-FEC BER, group delay, and so on. An integrated
frequency counter can measure any CW, AM, FM or television signal. The zero span mode
includes a built-in AM/FM demodulator.
As a rackmount instrument, AT2500HM is designed to be installed in a headend or hub to
rapidly align any broadband RF network, while instantaneously monitoring system
performance with documentation capability. Built-in preset measurement modes help automate
tests and procedures on multiple frequencies or channels within minutes. All the results can be
stored in non-volatile memory and later printed on a standard printer, either directly from the
AT2500HM or through your Ethernet network. Stored measurements may be downloaded to a
PC with VeEX’s file transfer and data management software that also allows measurement
data to be exported directly into a preformatted FCC report or third party PoP software.
The AT2500HM series analyzer provides speed and accuracy when taking measurements and
re-calibrates itself periodically or when it senses temperature variations and issues a warning
for any out-of-calibration conditions. This automatic and continual verification against stored
calibration curves ensures consistent and precise digital measurements, within the specified
limits. It constantly monitors internal temperature as well as its battery level.
The AT2500HM is typically used with optional software such as realWORX in order to
perform remote measurements. This manual describes the functionality of the AT2500HM as a
stand-alone spectrum analyzer. For information on the measurements and controls available
through the remote software, please consult the manual for the software package used.
1.2
Safety Requirements
Important: Review the following safety precautions to avoid injury and
prevent damage to this product or any product connected to it. To avoid
potential hazards, use this product only as specified. Only qualified
personnel should perform service procedures.
To avoid fire or personal injury:
1.
Use the proper power cord specified for this product and certified for the country of use.
2.
Ground the analyzer.
1-8
Chapter 1
Introduction
Always use a three-pronged AC power cord (supplied with the analyzer) and insert only
into a properly grounded three-pronged receptacle. Failure to ensure proper grounding
may expose users to a shock hazard, may damage the product and shall void the warranty.
Note:
Any attached equipment (customer supplied) must be grounded to the same protective
ground as the AT2500HM.
3.
Note:
Observe all terminal ratings. All signal connections made to the input port labeled RF IN
(“F” connector) shall:
• maintain proper ground continuity.
• be stripped of any AC or DC component higher than the maximum RF input rating
stated in the operating specifications.
At no time shall cable powering (higher than 90 VAC or VDC) be applied to the input port
RF IN. This may cause damage to the unit and shall void the warranty.
Consult the product manual for further ratings information before making connections to
the product.
1.3
4.
Replace batteries only with the proper type and rating specified, and respect terminals
polarity connections.
5.
Do not operate the unit with its covers removed.
6.
Do not operate with suspected failures. If you suspect there is damage to this product, have
it inspected by qualified service personnel.
7.
Do not operate in an explosive atmosphere.
8.
Do not operate outdoors.
Symbols and Terms
These terms and symbols may appear in this manual or on the product:
Warning:
Warning statements identify conditions or practices that could result in injury or
loss of life
Caution:
Caution statements identify conditions or practices that could result in damage to
this product or other property. When this symbol appears on the product, refer to
the manual.
Protective Ground:
(EARTH) Terminal
1.4
Model Designations for AT2500HM Series
AT2500HM Series Analyzer Model Designations:
HM
HMQ
Indicates Headend unit with
Includes QAM Analyzer
Monitoring Capability
Chapter 1
Introduction
1-3
Standard Measurement and Hardware Features
1.5
The following software and hardware features are standard on all AT2500HM series analyzers.
AT2CATVPAK
CATV Measurement Functions. Includes carrier measurement, precision
frequency counter, in-service Hum, CCN, CSO, CTB, In-channel
Response, Depth of Modulation measurements, and digital channel
power.
AT2TDM
Time domain measurement package for accurate level measurements of
bursty signals.
AT2VIDOUT
Baseband NTSC video output.
Ethernet 10/100
RJ-45 port and integrated firmware for high-speed access and remote
control.
High/Low pass
filters
Integrated band-selectable filters for use in bandpass filter mode or single
filter for high pass or low pass filter applications. Manual or automatic
modes available.
A99026010
WinCom II Data Management Software. PC-based software compatible
with the AT2500HM. Includes FCC report export capabilities.
One license included with each analyzer purchase. Package includes disk,
user manual and connection cables.
PSU2065
AC power supply adapter, with an input rating of 100-250 VAC, at
50/60 Hz.
The PSU2065 power supply with automatic switching connects to any
wall outlet with the above rating. An adaptor for the connection may be
required depending on the country where the AT2500HM is used. The
output is rated at 16 VDC, 4.06A. Certification complies with the
following: UL1950, UL136791, CSA950, LR36665, CE TUV / IEC
1950.
Caution:
The external power jack on the rear panel can ONLY receive power from the provided
PSU2065. Any attempts to power the AT2500HM from an external power source other
than the provided PSU2065 may result in poor operation or damage to your AT2500HM
series analyzer not covered under warranty. Using a power supply or charger with a
different rating may damage the power supply/battery charger and the AT2500HM.
Please contact VeEX if you need to power the AT2500HM from a source that is not
already approved.
1-
Chapter 1
Introduction
1.6
Available Options for AT2500HM Series
1.6.1
Software Options
1.6.2
1.6.3
A99026010
WinCom II Data Management Software. PC-based software
compatible with the AT2500HM. Includes FCC report export
capabilities.
One license included with each analyzer purchase. Package includes
disk, user manual and connection cables.
A99026020
WinRemote Remote Control Spectrum Analyzer Software. PC-based
software compatible with the AT2500HM. One license per PC.
Package includes disk, user manual and connection cables.
A99026050
WinQAM Remote Control QAM Digital Measurement Software. PCbased software compatible with the AT2500HM. One license per PC.
Package includes disk, user manual and connection cables.
RWORX-XMP
realWORX monitoring software Platform, must be ordered with at
least one monitoring module listed below. Includes all remote control
applications, realWORX Client, WinRemote, WinQAM, one
installation license for each of the remote control packages, user
manual, factory training.
RWORX-RMM
realWORX Return Path Monitoring Module. For Ingress/Spectral
automated monitoring
RWORX-AMM
realWORX Analog Monitoring Module, For Analog carrier level and
frequency automated monitoring.
RWORX-DMM
realWORX Digital monitoring module, For Digital QAM signal
automated monitoring.
Warranty and Calibration Options
ATWx2
Calibration service for “x” years (3-year or 5-year programs
available).
ATWx0
Extended warranty option for “x” years (additional 1 or 3 years for a
3-5 year total warranty).
Accessories
A65000909
1.7
Serial cable for PC connection DB-9 to DB-9 (STANDARD)
Warranty Information
VeEX products are warranted against defects in materials and workmanship for a period of 2
years from date of sale. VeEX agrees to repair or replace any assembly or component found to
be defective under normal use during this period. The obligation under this warranty is limited
solely to repairing the instrument that proves to be defective within the scope of the warranty
when returned to the factory. Transport costs to the factory are to be prepaid by the customer.
Chapter 1
Introduction
1-5
VeEX assumes no liability for secondary charges or consequential damages and, in any event,
VeEX’s liability for breach of contract shall not exceed the purchase price of the products
shipped and against which a claim is made.
Any application recommendation made by VeEX for the use of its products is based upon
tests believed to be reliable and accurate, but VeEX makes no warranty for the results
obtained. This warranty is in lieu of all other warranties, expressed or implied, and no
representative or person is authorized to represent or assume for VeEX any liability in
connection with the sale of our products other than set forth herein.
Repair and/or calibration is typically completed in 5 to 10 working days. Shipping costs are
paid by the factory only when returning equipment to a customer following warranty repair. It
is the responsibility the customer to notify the factory’s technical support persons prior to
shipping products for servicing, since many times problems may be solved over the telephone,
saving the user time and shipping costs. VeEX maintains regular office hours from 8:00 AM
to 8:00 PM Eastern time, Monday through Friday.
Customer Care:
Phone: +1 510 651 0500
E-mail: customercare@veexinc.com
Website: www.veexinc.com
Typical warranty on our products covers all parts and labor, as well as software and required
hardware updates. The warranty period starts from the day the equipment is delivered.
However, VeEX extends a grace period of 60 days after the end of the official warranty period
to cover any contingencies. Please note that the warranty period for rechargeable batteries is
three months and the grace period does not apply.
2-1
Chapter 2
GETTING STARTED
2.1
Receiving and Unpacking
The AT2500HM series analyzer is carefully packed at the factory in a shipping container
specially designed to prevent damage during transportation.
The original VeEX shipping container and packing materials should be saved since they may
be needed for long-term storage and for protecting the unit during transportation to the factory
for calibration or repair.
Note:
2.2
1.
Inspect the shipping container prior to accepting delivery. If any exterior damages are
present, notify the transport carrier immediately. VeEX is not responsible for damage
caused during shipping.
2.
Carefully open the shipping container without destroying it. Verify the contents of the
package. Each container should have the following:
1
AT2500HM series analyzer
1
PSU 2065 Power supply, 100-240 VAC, 16 VDC
1
User’s Guide
1
WinCom II software package
3.
Unpack the AT2500HM and inspect it for damage.
4.
Test the operability of the AT2500HM, using the procedure listed in section 2.4 Initial
Verification, on page 2-2. If you discover damage or operational defects, notify your
VeEX representative for instructions on how to proceed.
If the equipment has to be returned to an authorized VeEX service center, carefully
repackage it in the original shipping container and then contact VeEX’s customer
service department to obtain a Return Materials Authorization (RMA) number and proper
shipping instructions.
Physical Location
The AT2500HM series analyzer is intended for use indoors. See section 10.1, AT2500HM
Specifications for environmental compliance.
2.3
Electrical Connections
When connected to an external AC power source, the unit receives power both for normal
operation and to charge its backup battery. When disconnected from an external AC source, the
unit runs off of its internal battery. The green Power light is on whenever the unit is operating.
The AT2500HM’s internal battery has been fully cycled and charged at the factory before
shipping.
2-
2.4
Chapter 2
Getting Started
Initial Verification
The AT2500HM analyzer has been inspected and has passed all final operational and quality
control tests prior to being carefully packed for shipment. The AT2500HM should be activated
as soon as possible after receipt to verify that it operates in accordance with the specifications
listed in this manual.
To check the operation of the spectrum analyzer, follow these steps:
1.
Connect an external VGA monitor and PS2 or USB keyboard depending on the type of
ports on the rear panel.
2.
Turn the unit on. The power switch is located on the rear panel.
3.
When the unit has passed its initial self-test and calibration, the remote mode screen will
appear indicating that the AT2500HM is offline and waiting for a remote connection.
Figure 2-1: Spectrum Analyzer Default Remote Settings
4.
Press ESC to enter the remote menu. Use the arrow keys to select EXIT REMOTE icon
and press ENTER.
Chapter 2
Getting Started
2-3
Figure 2-2: Remote menu
5.
Now use the arrow keys to select the SPECTRUM ANALYZER icon and press
ENTER. The spectrum analyzer screen appears with the default instrument settings (see
below).
The default settings when shipped from the factory are as follows:
Mode
Spectrum Analyzer
Span
Full span (5 MHz–1.5 GHz)
Resolution Bandwidth
1 MHz
Sweep Time
30 milliseconds
Amplitude
30 dB of input attenuation
Center Frequency
750 MHz
Figure 2-3: Spectrum Analyzer Default Instrument Settings
2-4
Chapter 2
Getting Started
6.
If the unit finds an error in the initial self-test, it displays error messages on the screen
during the boot-up sequence.
7.
If the main electronics pass the initial self-test but an RF error occurs during selfcalibration, the AT2500HM displays an “uncal” message below the VeEX logo at the
bottom left corner of the screen.
Figure 2-4: Uncalibrated Measurement
8.
Press F7 to display the main menu options. Note the time, date, temperature and battery
voltage readings at the top of the screen.
9.
Apply a stable carrier wave (CW) RF signal of known frequency and level (for example,
40 MHz at +10 dBmV) to the AT2500HM’s input.
10. Using the arrow keys, select the FREQUENCY COUNTER icon from the main menu
and press ENTER.
11. Tune to the desired frequency by pressing F1 and entering the center frequency, in
megahertz, of the CW signal. Press ENTER.
12. Verify the accuracy of the frequency and level displayed. If the frequency and level are
correct, the AT2500HM is functioning normally.
13. You can return the AT2500HM to the default remote mode by pressing the PAGE
DOWN button on the keyboard or by turning the unit off, waiting a few seconds and
turning the unit back on.
3-1
Chapter 3
UNDERSTANDING THE
AT2500HM
This section provides general information to help you become familiar with the shortcut keys
and the basic operation of the AT2500HM. It includes a detailed description of the front and
rear panels and an explanation on the use of standard features.
To operate the AT2500HM you will need to connect an external VGA monitor and a keyboard
with a PS2 type connector.
3.1
Automatic Calibration
The AT2500HM automatically calibrates itself according to the current ambient temperature,
and then monitors the temperature continuously, recalibrating as required. It is fully calibrated
to traceable standards and includes calibration data in its non-volatile memory.
3.2
AT2500HM Online Help
Context-sensitive help screens can be called up any time during the operation of the instrument.
Figure 3-1: AT2500HM Online Help
In all modes of operation, the help system is continuously available to assist the user with
step-by-step instructions. The help system includes tips and reminders as well as detailed
descriptions of each menu function.
To access the help system, press the DELETE key. Use the left/right arrow keys to scroll
through the text line by line, or use the up/down arrow keys to scroll page by page. Press
ENTER to return to the start of the text, or press ESC to exit the help system and return to the
previous mode of operation.
3-2
Chapter 3
Understanding the AT2500HM
3.3
AT2500HM User Interface
3.3.1
Front Panel
Figure 3-2: Front View of the AT2500HMQ2
LED
Use
Sweep TX
For future use
Data TX
Data transmit on COM1 – COM4
Data RX
Data receive on COM1 – COM4
Remote RF
For future use
COM1
Indicates connection on COM1
Local
Indicates AT2500HM in local mode
Power
Indicates AT2500HM is operational
Figure 3-3: Front View of the AT2500HMQ3
LED
Use
Network Link
Indicates network has active link
Network ACT
Indicates network activity
Data TX
Data receive on COM1 – COM4
Monitoring
Indicates AT2500HM in monitoring mode
Remote
Indicates AT2500HM in remote mode
Local
Indicates AT2500HM in local mode
Power
Indicates AT2500HM is operational
Chapter 3
3-3
Understanding the AT2500HM
3.3.2
Rear Panel
Figure 3-4: Rear View of the AT2500HMQ2 with parallel port
Connector
Use
Type
1.
COM1-COM4
RS-232 data port
9-pin D type
2.
ASI OUTPUT (optional)
Asynchronous Serial Interface transport
stream output for MPEG transport stream
BNC
3.
VIDEO I/O (optional)
For future use
BNC
4.
RF IN
RF signal input
Female F type
5.
POWER SWITCH
On/Off Power Switch
Switch
6.
AUX. VIDEO OUTPUT
NTSC video display output
BNC
7.
VGA OUTPUT
VGA monitor connector
15-pin D type
8.
DC IN 16 V
Power supply input
5-mm jack
9.
KEYBOARD
External keyboard
PS2 type
10. NETWORK
Ethernet communication port
RJ-45
11. LPT1
Parallel printer port
25-pin D type
3-4
Chapter 3
Understanding the AT2500HM
Figure 3-5: Rear View of the AT2500HMQ3 with USB ports
Connector
Use
Type
1.
COM1-COM4
RS-232 data port
9-pin D type
2.
ASI OUTPUT (optional)
BNC
Asynchronous Serial Interface transport
stream output for MPEG transport stream
3.
VIDEO I/O (optional)
For future use
BNC
4.
RF IN
RF signal input
Female F type
5.
POWER SWITCH
On/Off Power Switch
Switch
6.
AUX. VIDEO OUTPUT
NTSC video display output
BNC
7.
VGA OUTPUT
VGA monitor connector
15-pin D type
8.
DC IN 16 V
Power supply input
5-mm jack
9.
NETWORK
Ethernet communication port
RJ-45
Printer and external keyboard
2 x USB A type
10. USB 1 & 2
Chapter 3
3-5
Understanding the AT2500HM
3.3.3
Keyboard Shortcut Keys
An external keyboard is used to select the functions on the AT250HM. Within most of the
measurement and configuration screens the function keys F1 to F6 serve as context sensitive
softkeys.
The function for each softkey is displayed on the right side of the screen from top (F1 key) to
bottom (F6 key). Note that the functions vary depending on the mode and menu, providing
access to various options within the selected mode. Depending on the selected mode of
operation, some of the softkeys may be shortcuts to other test modes.
Below is a list of all keyboard shortcuts and their function.
Function
External
Keyboard
Key
Description
F1 to F6
F1 to F6
Context sensitive softkeys F1 to F6. These six keys change
functionality based on the current mode of operation. Each
key’s function appears on the right edge of the screen.
Main Menu
F7
Displays the main menu screen that provides direct access
to the various test options and setup functions.
Frequency
]
Displays the softkey choices used to set the center
frequency, either by entering a frequency directly (in MHz)
or by entering the video or audio channel number, as
defined in the channel plan.
Span
\
Displays the softkey choices used to set the span, resolution
bandwidth (RBW), video bandwidth (VBW), sweep time
(SWT) and signal trigger settings.
Amplitude
[
Displays the softkey choices used to set amplitude related
parameters: attenuator, reference level, vertical scale and
reference offset.
Markers
;
Displays the softkey choices used to set the horizontal and
vertical markers for indicating and/or measuring level and
frequency references. Pressing the V2 marker softkey
twice activates the noise marker (dB/Hz) function.
Trace
‘
Displays the softkey choices used to choose signalprocessing functions: digital average 1, digital average 2,
peak hold or no average.
Previous
Mode
F8
Shortcut to the previous measurement mode and instrument
settings.
Store
Insert
Displays the softkey choices used to store measurement
records (up to 250) or instrument settings (up to 100).
Recall
Home
Displays the softkey choices used to bring up saved settings
and/or records.
Preset
Page Up
Clears the current instrument settings and returns the unit to
factory default settings.
Help
Delete
Calls up context-sensitive help screens.
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Chapter 3
Understanding the AT2500HM
Function
External
Keyboard
Key
Print
End
Remote
Prints an image of the current screen directly to most
printers with a USB or parallel port. You may choose either
an Epson compatible or an HP LaserJet compatible parallel
printer driver in the setup parameters. Note that the
AT2500H does not work with all available printers on the
market. Contact VeEX for recommendations, or test
compatibility before purchasing a particular printer.
Page Down Runs the built-in communications software for
downloading and uploading of files, using a standard RS232C connection or an Ethernet connection.
Esc
Esc
Memory
F9
Adds a screen trace to volatile (temporary) memory. This
feature may be used to compare a live trace with a captured
trace in volatile memory. To save a trace in non-volatile
memory, use the INSERT key.
Memory
Clear
F10
Clears the trace data currently in volatile memory, and
clears a recalled trace from the screen display.
Enter
Arrow keys
Enter
Confirms commands or saves entries.
The arrow keys move items up and down or left and right,
depending on the context. Used for incremental change of
values such as center frequency, reference level, and marker
position. The up/down arrow keys provide a greater
incremental change than the left/right in any given mode.
↑
←↓→
3.4
Description
Returns to the previous menu selection.
Main Menu Software Functions
The F7 key displays the AT2500HM main menu containing the icons for each available
feature. To select one of the icons, use the arrow keys to scroll to the function you want, and
then press ENTER.
The top line of the screen shows the external temperature, in degrees Celsius or Fahrenheit
depending on user preferences. It also shows the battery voltage and the current date and time.
Chapter 3
3-7
Understanding the AT2500HM
Figure 3-6: Main Menu Icons
3.4.1
Standard Functions and Icons
Spectrum Analyzer
Full function 5 MHz to 1.5 GHz spectrum analysis
Digital Ch. Power
Measures the average RF power of digitally modulated carriers such as 64 and 256
QAM or RF spectrum bandwidth by setting the center frequency and measurement
bandwidth.
QAM Analyzer
The built-in QAM demodulator makes it possible to measure in-service 64/256 QAM
digital signals. It displays the QAM constellation with zoom capabilities, adaptive
equalizer taps, in-channel flatness, group delay, pre- and post-bit error rate (BER),
modulation error ratio (MER), error vector magnitude (EVM), errored seconds and
severely errored seconds. Also provides QAM impairment analysis (QIA).
Freq. Counter
Measures the selected center frequency, with ±0.75 dB level accuracy and 1-PPM
frequency accuracy.
TV Channel
Measures the selected TV channel (visual and aural carriers), with the same accuracy
as the frequency counter.
Multi-Carrier
Scans up to 6 user-specified reference carriers. Markers may be used in this mode to
measure deltas in level. This feature can be used to view RF amplifier tilt (slope) and
gain, to make adjustments to the amplifier and to view the results in real time.
Auto Test
Measures tagged channels in the active channel plan, with the same accuracy as the
frequency counter. Measures 80 analog channels (video and audio carriers) in less
than a minute.
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Chapter 3
Understanding the AT2500HM
Video
Takes baseband video measurements such as differential gain and phase,
chrominance/luminance delay and gain, depth of modulation linearity, signal-to-noise
(S/N) weighted or unweighted. Includes choice of waveform monitor or vectorscope
display.
Hum
Measures hum modulation distortion. Results are shown in peak-to-peak percent and
dBc (decibels below carrier level).
CCN, CSO, CTB
Provides test options for three parameters: CCN, CTB and CSO. Tests are performed
separately or simultaneously combined. Can also perform all 3 measurements in
gated, non-intrusive test modes without service interruptions.
In-Channel Freq.
Measures in-channel frequency response in-service using a ghost canceling reference
signal, video sweep or a CATV multiburst test signal in the VITS lines of a video
channel.
Depth of Mod.
Measures the video depth of modulation as a percentage in both graphical and
numeric format. A white reference test signal transmitted on the VITS of program
video provides a standard for calibrating the video depth of modulation.
Time Domain
Measures burst levels, signal-to-noise (S/N) and total channel power of upstream
DOCSIS channels, with faster horizontal sweep times than in the spectrum analyzer’s
zero span mode.
Setup
Displays the AT2500HM’s model number, operating software version, serial number
and installed options. Allows the user to configure operational parameters, color
setup, channel plans and configure remote mode operation.
Remote Mode/ Exit Remote
Enables or exits the AT2500HM’s remote mode, which is used to download or
upload records, configuration files (channel plans, colors etc.) between a PC and the
AT2500HM. Remote mode also enables remote control of the AT2500HM through
software such as WinCom II, WinRemote, WinQAM, or realWORX.
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Chapter 4
BASIC AT2500HM FUNCTIONS
4.1
Default Instrument Settings
The PAGE UP key resets the AT2500HM to a saved default state.
The AT2500HM’s factory-set default state is Spectrum Analyzer with the following settings:
• Full span (1500 MHz)
• Center frequency set to 750 MHz
• Resolution bandwidth of 1 MHz
• Sweep time of 30 ms
• 30 dB of input attenuation
Storing and Recalling Measurement Records or
Instrument Settings
4.2
Measurements, traces and instrument settings are stored as records in non-volatile memory for
later viewing, printing or transferring to a computer. The AT2500HM can store up to 250
measurement records and 100 instrument settings. You can then select any record from the
Recall Records or Recall Settings directory listing when needed.
Note:
If you are storing records and instrument settings for your proof-of-performance or FCC
testing and compliance documentation, you must include all pertinent information about
the test equipment used for the measurements. This means that certain information for
the AT2500HM must be entered in order to output the correct reports. See the WinCom II
User Guide for instructions. The VeEX report headers include the model and serial
number, last factory calibration date of the instrument as well as basic information such
as date, time, temperature, company name and user name. If you are using VeEX’s
WinCom II data management software, you can export your stored traces from the
analyzer to your PC. From WinCom II, the measurement results can then be exported
directly into either:
•
•
an SRT Broadband preformatted Excel Macro FCC PoP report, using a .CSV file
format, or
a .TSD file on your PC, that is then imported into PoP Family ware (see the WinCom
II User Guide for instructions.)
For FCC exports, it is important that the site ID be entered in a specific format in order for the
software to recognize formatting and populate the proper cells.
4.2.1
Storing Measurement Records
You can store up to 250 different measurement records in the AT2500HM’s memory. To save
a measurement record:
1.
Press the INSERT key and then press F1 STORE RECORDS.
2.
Type in a unique filename (up to 16 characters), and then press ENTER.
3.
If desired, edit the site ID (up to 8 characters), and then press ENTER.
4.
If desired, enter a comment (up to 40 characters) and press ENTER. You can also leave
this field blank. Press ENTER again to save the record.
Each record is automatically saved with the extension .XML and contains:
• the name and comment fields
• the mode (such as spectrum analyzer) and the display settings
• the time and date
• the actual trace or information on screen at the time of capture
4-2
4.2.2
Chapter 4
Basic AT2500HM Functions
Storing Settings
You can store up to 100 different instrument configurations in the AT2500HM. Before storing
the setup, instrument settings such as span, attenuator settings, bandwidth adjustment as well as
the frequency or channel position must be set in advance.
To store the settings:
1. Press the INSERT key , and then press F2 STORE SETTINGS.
2. Type in a unique filename (up to 16 characters), and then press ENTER.
3. If desired, edit the site ID (up to 8 characters), and then press ENTER.
4. If desired, enter a comment (up to 40 characters) and press ENTER. You can also leave
this field blank. Press ENTER again to save the record.
Each stored setting contains:
• the name and comment fields
• the mode (such as spectrum analyzer) and the display settings
• the time and date
4.2.3
Recalling Stored Records
Stored records are linked to the analyzer mode in use. In order to recall one of these records, the
analyzer must be in the same mode. There are several ways to return to a particular mode. For
example, you can:
• select an icon from the main menu;
• select a softkey shortcut (if available);
• use the ESC or F8 key.
To access stored records:
1. Once the analyzer is in the correct mode, press HOME and then select F1 RECALL
RECORDS to display the list of records.
2. Using the arrow keys, highlight the record you want to recall. You can now view or
superimpose the trace over the live signal:
• To superimpose the trace, press ENTER.
• To view (display on screen) the content of a record on screen before recalling it, press
F1 DISPLAY ITEM. From this view, you can recall and superimpose the record over
a live trace by pressing ENTER. To return to the list of saved records, press F1 FILE
MANAGER.
Figure 4-1: Recalling Stored Records
Chapter 4
Basic AT2500HM Functions
4.2.4
4-3
Recalling Stored Settings
To recall a particular test setup:
1.
Press HOME and then select F2 RECALL SETTINGS.
2.
Using the arrow keys, highlight the settings you want to recall. You can now view or
immediately recall the setup:
• to recall the setup immediately, press ENTER.
• to view the content of the setup, press F1 DISPLAY ITEM. To apply the viewed
setup, press ENTER. To return to the list of saved settings, press F1 FILE
MANAGER.
Figure 4-2: Selecting a Stored Settings File
Figure 4-3: Displaying the Parameters in a Stored Settings File
4-4
4.2.5
Chapter 4
Basic AT2500HM Functions
Superimposing a Record on a Live Trace
With the AT2500HM, you can recall a stored trace and superimpose it on a live trace for
comparing. The superimposed trace appears in a specific color on the screen.
Figure 4-4: Superimposing a Trace on a Live Display
To superimpose a trace:
4.2.6
1.
Press HOME, and then press F1 RECALL RECORDS.
2.
Using the arrow keys, scroll through the records and highlight the record. Press ENTER
to superimpose the trace on the current live trace.
3.
To clear the superimposed trace, press the F10 key.
Freezing a Live Trace
With the AT2500HM, you can capture a single trace on screen in order to compare it with
traces the analyzer is acquiring. To capture a trace, press F9. The static trace appears in a
specific color on the screen, along with newly acquired traces.
To capture a live trace:
1.
Press the F9 key.
2.
To clear a captured trace, press the F10 key.
Please note that any traces captured with the F9 key are not stored with the saved records. The
captured traces are stored in the AT2500HM’s volatile memory. Once the captured trace is
cleared with the F10 key, it cannot be recalled. To store a trace in non-volatile memory, use the
INSERT key instead of the F9 key.
Chapter 4
Basic AT2500HM Functions
4.2.7
4-5
Erasing Records and Settings
The AT2500HM can store 250 measurement records and 100 analyzer settings. Once this limit
has been reached, the storage mechanism operates on a first-in, first-out (FIFO) basis. As new
measurements or settings are stored, the oldest ones are overwritten so that the total number of
measurements and settings is still 250 and 100 respectively. To avoid losing older records,
download the stored data to a PC regularly or erase stored records and instrument settings that
are no longer needed. See section 4.4, Data Communications on page 4-7 for more information
on connecting a PC to the AT2500HM. Note that you need to put the AT2500HM in remote
mode either by pressing the PAGE DOWN button or by selecting the REMOTE icon.
Figure 4-5: Erasing Tagged Records
To delete records:
4.3
1.
First tag the records you want to delete, using one of the following methods:
• to delete only a few records, use the arrow keys to scroll through the records on the
current page. To view records on undisplayed pages, use the up/down arrow keys.
Tag the highlighted record by selecting F3 TAG ITEM.
• to delete all records, select F4 TAG ALL ITEMS.
2.
Once the records are tagged, select F6 DELETE TAGGED ITEMS. At the prompt, press
ENTER to continue or ESC to cancel the operation. At the second prompt press ENTER
to permanently delete all tagged items or ESC to cancel the operation.
Printing Reports and Screens
The newest version of the analyzer, the AT2500HQ3 has replaced the parallel printer port and
PS2 keyboard port with two A type USB ports. The AT2500H supports several different makes
of printer through its USB ports. When using a USB printer the AT2500H automatically selects
the correct printer driver.
Using the parallel port, the AT2500 supports two printer drivers:
• a standard Epson compatible driver, which works well with most types of dot matrix
and ink jet printers, and
• a driver emulating the HP LaserJet standard for laser printers.
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Chapter 4
Basic AT2500HM Functions
The most common ink jet printers generally work well with the AT2500H. However, your
printer may not be 100% compatible with the AT2500H. If you do need to purchase a printer
for your analyzer, we recommend you contact your VeEX Telecom Broadband representative
or save a few traces in your analyzer and bring it to the store with you to try it before making
your purchase.
4.3.1
Setting up the Printer
To connect the AT2500H to a compatible USB printer:
1.
Turn on both the AT2500 and the printer.
2.
Use a standard USB cable to connect the printer to the AT2500 using either of the two
USB ports on the rear panel. Please note that some printers may not be compatible.
To connect the AT2500 to a compatible parallel printer:
4.3.2
1.
Use a standard printer cable with 25-pin connectors. Run this cable between the printer
and the AT2500’s 25-pin port labeled LPT1. This port is located back panel of the unit.
Please note that some printers may not be compatible.
2.
From the main menu, select the SETUP icon and choose the appropriate printer driver.
See section 4.5.1, Choosing General Operating Parameters, on page 4-17 for complete
instructions
Printing a Screen
Individual screens can be printed out from the current display once the printer has been set up
(see section 4.3.1, Setting up the Printer).
To print the screen, press the END key. An error message appears if there are any problems
either with the printer configuration or cable connection. If a message does appear (see Figure
4-6), make sure that the printer cable is connected and that the appropriate printer driver is
selected.
Figure 4-6: Printing Errors
Chapter 4
Basic AT2500HM Functions
4.3.3
4-7
Printing Multiple Records
Multiple screens can be printed out from the stored records once the printer has been set up(see
section 4.3.1, Setting up the Printer).
To select and print multiple stored records:
1.
Press HOME, and then press F1 RECALL RECORDS.
2.
Use the arrow keys to scroll through the records. Highlight the records you want to print.
To view records on undisplayed pages, use the arrow keys. Tag the highlighted record by
selecting F3 TAG ITEM. To tag all records, select F4 TAG ALL ITEMS.
3.
Once the records are tagged, select F5 PRINT TAGGED ITEMS. An error message
appears if there are any problems either with the printer configuration or cable connection.
If a message does appear (see Figure 4-6), make sure that the appropriate printer driver is
selected.
The VeEX report headers include the model and serial number, last factory calibration date of
the instrument as well as general information such as date, time, temperature, company name
and user name.
Data Communications
4.4
The AT2500HM supports a connection to a PC or other device in several ways:
• a direct serial link for RS-232 communications
• a telephone modem link for RS-232 communications
• an Ethernet connection for TCP/IP communications over a LAN
The first two connection types require the use of one of the AT2500HM’s 9-pin D type
connector labeled COM1 to COM4 on the rear pane. If you connect your PC directly to the
AT2500HM, you must use a null modem cable. Note that you need to put the AT2500HM in
remote mode either by pressing the PAGE DOWN button or by selecting the REMOTE icon.
You must install VeEX’s WinCom II or WinRemote software on your PC and run the
program in order to established communications with the AT2500HM.
Note:
4.4.1
This manual covers the AT2500HM functions and operation only. Please refer to the
documentation accompanying the VeEX software for more information on using serial
communications.
Connecting the AT2500HM to a LAN
The AT2500HM supports an Ethernet 10Base-T connection to a local area network (LAN) via
the RJ-45 network connector on the rear panel. You can assign a static IP address to the
AT2500HM, or you can let the AT2500HM obtain a network assigned IP address from a
DHCP server. Contact your system administrator if you are unsure of the IP settings you should
use.
Note that other settings may affect a remote connection. In the user parameters (see section
4.5.1, Choosing General Operating Parameters on page 4-17), make sure that the system type is
set to “Server”.
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Chapter 4
Basic AT2500HM Functions
Figure 4-7: Setting up a LAN Connection
To set up a network connection:
1.
Connect the AT2500HM to your network using a straight-through standard CAT-5
Ethernet cable, or directly to your PC using an Ethernet crossover cable.
2.
On the AT2500HM, choose the SETUP icon from the main menu, and then select F5
REMOTE SETUP.
3.
Scroll to the Connection Device field, and press ENTER to select TCP/IP.
4.
Using the left/right arrow keys, scroll to the DHCP Usage field and select one of the
following:
• ON if you want the AT2500HM to obtain an IP address automatically on your
network
If the analyzer was not connected with an Ethernet cable to the local network where
an IP can be acquired, a message appears on screen in a red box indicating that the
TCP/IP network is down. This means the network setup has not been applied.
Connect your analyzer with an Ethernet cable to your network where an IP address
can be assigned automatically, complete the network setup (see step 0) and then press
F1 Network Init to initialize the connection. If successful, the message “TCP/IP
Network Up” appears in a green box.
•
5.
OFF if you want to manually configure the AT2500HM’s IP address
If there is no DHCP server available to assign addresses, you can manually assign an
IP address to the AT2500HM. For a direct Ethernet connection with a crossover
cable, choose OFF and manually configure the IP addresses of the AT2500HM and
your PC.
Using the arrow keys, select the TCP/IP communication parameters:
• Domain Name
• Host Name
• IP Mask
• DHCP Usage (“OFF” for manual IP assignment)
• IP Address (only if you selected OFF in step 0)
Chapter 4
Basic AT2500HM Functions
•
Note:
4-9
Gateway Address
If devices in your network do not use a gateway, you must configure the AT2500HM’s
IP address so that its base address matches your network.
The AT2500HM does not support Host Name identification on a TCP/IP network. The
AT2500HM must be identified by the IP address. Care should also be taken when using
DHCP to ensure that the lease time on an IP address is long enough for your application.
6.
Using the arrow keys, select the client/server parameters:
• system type (client or server; use Server to access the AT2500HM by remote)
• system ID (used by remote software such as WinCom II or WinRemote to recognize
the connection from the PC to the analyzer. Must be set to the same ID as your
software)
• server ID (only if you selected Client as the system type)
• server live display
Figure 4-8: Activating the Server Live Display for Broadband Switches
7.
Set the frame rate at which the AT2500HM sends traces in remote mode. Choose a value
from 1 to 30 frames per second.
8.
Press F1 NETWORK INIT in order for the new IP address to take effect. If the network
connection is valid, the message “TCP/IP Network Up” appears on screen in a green box.
9.
Press F5 SAVE SETUP to store the new communication parameters and then press ESC
to return to the main menu.
10. From the main menu, select the REMOTE MODE icon. If the text below the icon says
“EXIT REMOTE” you are in remote mode and can continue to the next step. If it says
“REMOTE MODE”, position the cursor on the icon and press ENTER. The text at the
top of the screen should now indicate “Remote Menu”.
11. Scroll to the Spectrum Analyzer icon and press ENTER. You should see a blank spectrum
display with “Remote Spectrum Mode” in the upper left corner of the spectrum area, or
you may see a “Remote Spectrum” window box in the middle of the screen if you selected
“On” or “Off” in the Server Live Display setting in the Setup Remote page.
The AT2500HM is now ready to be controlled remotely via a LAN.
4-10
4.4.2
Chapter 4
Basic AT2500HM Functions
Connecting a PC directly to the AT2500HM
Pressing the PAGE DOWN key configures the AT2500HM as a file server. This allows a
program such as WinCom II to access the contents of the non-volatile memory as if it were a
disk drive on a PC. It also allows a program such as or WinRemote or WinQAM to take
control of the AT2500HM by remote. Note that you must put the AT2500HM in remote mode
either by pressing the PAGE DOWN button or by selecting the REMOTE icon.
Figure 4-9: Setting up an RS-232 Connection
1.
Connect a PC to the AT2500HM’s COM1 port using a standard null modem cable or
crossover Ethernet cable. These cables are included in the VeEX software packages. For a
direct Ethernet connection, your PC and the AT2500HM must have IP addresses within
the same range to allow communication. Refer to section 4.4.1 Connecting the
AT2500HM to a LAN, on page 4-7, and follow the instructions in steps 4 and 5 for
manually configuring an IP address on the AT2500HM. Refer to your Windows
documentation to set up your IP address on your PC.
2. On your PC, set up the communication parameters (baud rate, data bits, parity, etc.) so that
they match the settings on the analyzer before attempting communications. Please note
that the maximum baud rate for serial communication is 115,200 baud.
3.
On the AT2500HM, choose the SETUP icon from the main menu, and then select F5
REMOTE SETUP.
4.
Using the arrow keys, scroll to Connection Device, and press ENTER to select COM1.
5.
Using the arrow keys, select the communication parameters:
• baud rate (115200 baud recommended)
• flow control delay
6.
Using the arrow keys, select the client/server parameters:
• system type (use Server to access the AT2500HM by remote)
• system ID (used by software such as WinCom II or Win Remote to recognize the
connection from the PC to the analyzer. Must be set to the same ID as your software.)
• server ID (only if you selected Client as the system type)
7.
Press F5 SAVE SETUP to store the new communication parameters and then press ESC
to return to the main menu.
8.
To use WinCom II with the AT2500HM, select the REMOTE MODE icon from the
main menu. If the icon reads EXIT REMOTE you are in remote mode and can continue to
Chapter 4
Basic AT2500HM Functions
4-11
the next step. If it says REMOTE MODE, position the cursor on the icon and press
ENTER. The text at the top of the screen should now indicate “Remote Menu”.
9.
Scroll to the Spectrum Analyzer icon and press ENTER
10. Once the transfer is complete, press ESC to access the main menu, and then select the
EXIT REMOTE icon to return the AT2500HM to its normal mode of operation.
4.4.3
Configuring the AT2500HM Remote Mode
You can use the AT2500HM through a computer if you have set up the remote function, either
by pressing the PAGE DOWN button or by selecting the REMOTE icon.
On the AT2500HM, choose the SETUP icon from the main menu, and then select F5
REMOTE SETUP. You can now choose the method you want to use to communicate with
your analyzer for data management or remote control. See section 4.4, Data Communications
on page 4-7 for instructions on setting up an RS-232 or Ethernet connection.
Once the remote setup is complete, the settings are stored in the AT2500HM. You need to
activate remote mode if you are using a remote application such as WinCom II or WinRemote.
For further instructions, see section 4.4.5, Transferring AT2500HM User Files with on page 412, or section 4.4.6, Using WinRemote with the AT2500HM on page 4-14.
Figure 4-10: Activating Remote Mode
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4.4.4
Chapter 4
Basic AT2500HM Functions
Upgrading Firmware
WinCom II includes a simple utility for upgrading the AT2500 firmware. Depending on
whether you are upgrading an AT2500HQ2 with parallel port or an AT2500HQ3 with USB
port the file extension of the firmware file will be different. The firmware has an extension of
.TAR.GZ for an AT2500H with a parallel port and .RUN for an AT2500H with a USB ports.
Your channel plan is still in memory, but it may not be selected as the default plan. All stored
measurements and settings are also kept in memory. As a precaution, download the stored data
from the AT2500HM every time you upgrade or update the firmware to avoid the possibility of
losing data due to the incompatibility of a given parameter. See section 4.4, Data
Communications on page 4-7 for more information on connecting a PC to the AT2500HM.
Note that the AT2500HM must be in remote mode either by pressing the PAGE DOWN
button or by selecting the REMOTE icon.
To upgrade the AT2500HM:
1.
Make sure you have the appropriate firmware. VeEX provides update files on disk, or
they can be downloaded from the website at www.VeEXtelecom.com. You must have a
password in order to download files from the web site. Contact VeEX’s customer support
department to obtain a password.
2.
Press the PAGE DOWN key to put the unit in communication mode.
3.
Run the WinCom II software and establish communication with the AT2500HM. See
section 4.4.1 or 4.4.2 beginning on page 4-7 for instructions on setting up a direct or LAN
connection.
4. Select Upgrade Firmware from the WinCom II communications menu. Using the dialog
box, select the firmware file. The firmware file has the extension “.RUN” if the
AT2500HM has USB ports or the extension .TAR.GZ if the AT2500H has a parallel
printer port.
4.4.5
5.
Double-click on the file to start the upgrade procedure.
6.
Once the file transfer is complete, WinCom II will attempt to reconnect to the AT2500. It
may take several minutes for the new firmware to load in the AT2500, in which case the
reconnect attempt will time out. If the reconnect process times out, wait a few minutes and
try to connect to the AT2500 again.
7.
Remember to set up your user parameters (see section 4.5.1, Choosing General Operating
Parameters on page 4-17).
Transferring AT2500HM User Files with WinCom II
Use the VeEX WinCom II data manager software to retrieve individual records or a set of
records. In order to retrieve records from the AT2500HM, you must establish a communication
connection with the AT2500HM. See section 4.4.1 or 4.4.2 beginning on page 4-7 for
instructions on setting up a direct or LAN connection. See section 4.4, Data Communications
on page 4-7 for more information on connecting a PC to the AT2500HM. Note that in order to
use WinCom II, the AT2500HM must be put in remote mode either by pressing the PAGE
DOWN button or by selecting the REMOTE icon.
The information that you record about your measurement traces includes date, time, instrument
serial number, user name, company name, temperature, instrument calibration date and so on.
The following directories contain saved files on the AT2500HM. All files are saved under the
user-defined file name, with the appropriate extension (see below).
Chapter 4
Basic AT2500HM Functions
Channel Plans
Channel plans for NTSC, PAL or other television standards.
Format “.ACP” (proprietary binary format)
Color Settings
Customized color settings used on the AT2500HM analyzer.
Format “.CLR” (proprietary binary format)
Parameter File
User preferences on the AT2500HM analyzer.
Format “.PRM” (proprietary binary format)
QAM Normalization
Stored QAM Normalization files.
4-13
Format “.XML”
Settings Records
Stored instrument setups. Using the same settings files on multiple
units make consistent measurements. Note that to recall a setup, you
must be in the appropriate mode for that setup.
Format “.XML”
Switch Configuration
User preferences of external switches.
Format “.SWT” (proprietary binary format)
Trace Records
Stored measurement records and traces. Note that to recall a trace,
you must be in the same mode that you were in when the trace was
captured.
Format “.XML”
Figure 4-11: Copying User Files0
4-14
4.4.6
Chapter 4
Basic AT2500HM Functions
Using WinRemote with the AT2500HM
The VeEX WinRemote software provides remote control access to AT2500HM spectrum
analyzers. It offers full control of the spectrum analyzer functions such as center frequency,
span, resolution bandwidth settings and so on. Note that to use WinRemote, the AT2500HM
must be in remote mode either by pressing the PAGE DOWN button or by selecting the
REMOTE icon.
WinRemote’s functions and menus are similar to the menus of the AT2500HM spectrum
analyzer insofar as possible. WinRemote includes capabilities for storing and viewing recorded
traces, and can also export the measurement data to the Windows clipboard (in BMP format).
Data you have collected can be printed through WinRemote.
Depending on the quality of your Ethernet link, real-time screen refresh on your PC is typical at
25 frames per second (fps). You can set the frame rate in the remote setup menu (see section
4.4.1, Connecting the AT2500HM to a LAN on page 4-7).
WinRemote can also tap into a bank of VeEX RF test point selectors such as the AT1601M,
so that you can select up to 256 different test points remotely. Switches from other vendors are
compatible with the AT2500HM. Contact your local VeEX representative for further details.
Note that the switches can only be controlled through the AT2500HM’s RS-232 COM port.
Figure 4-12:Using WinRemote with the AT2500HM
Chapter 4
Basic AT2500HM Functions
4.4.7
4-15
Using WinQAM with the AT2500HM
The VeEX WinQAM software provides remote control access to AT2500HM analyzers. It
offers control of the unit’s QAM analyzer measurement functions such as digital channel
power, constellation view, statistical graph view, and adaptive equalizer display. Note that in
order to use WinQAM, the AT2500HM must be put in remote mode either by pressing the
PAGE DOWN button or by selecting the REMOTE icon.
WinQAM’s functions and menus are similar to the menus of the AT2500HM QAM analyzer
insofar as possible. WinQAM includes capabilities for storing and viewing recorded traces, and
can also export the measurement data to the Windows clipboard (in BMP format). Data you
have collected can be printed through WinQAM.
The AT2500HM can acquire data for QAM statistics over a period as long as 60 minutes. With
a remote WinQAM connection, this period can be extended to up to 7 days.
Figure 4-13: Using WinQAM with the AT2500HM
4-16
4.5
Chapter 4
Basic AT2500HM Functions
Setting up the AT2500HM Preferences
The AT2500HM’s initial settings can be customized according to individual user requirements.
To display the setup screen (Figure 4-14), press F7 and then select the SETUP icon.
The Setup screen displays important information about your AT2500HM, such as model and
serial numbers, software version, calibration date and time. It also shows all installed options
and indicates which options are enabled for use locally or remotely on your analyzer. Note that
some features might appear that are available as separate options for legacy products.
Additional information includes certain user preferences such as the active channel plan and the
active color setting.
Figure 4-14: Setup Screen
From the Setup screen, select one of the following keys to customize a specific item:
F1
PARAMETERS: Used to select global parameters for the AT2500HM. These
parameters are independent of the user and mode.
F2
COLORS: Used to define custom color schemes.
F3
CHANNEL PLANS: Used to edit channel line-ups for each headend.
F4
SWITCH SETUP: Used to set up a test point switch.
F5
REMOTE SETUP: Used to configure the AT2500HM’s COM port or Ethernet port for
remote communication.
F6
NTSC OUT ON/OFF: Used to toggle the NTSC output on or off.
Chapter 4
Basic AT2500HM Functions
4.5.1
4-17
Choosing General Operating Parameters
The Parameter screen displays global parameters set on the AT2500HM such as power off
delay, beep on/off preferences as well as the type of printer driver and current date format.
Figure 4-15: Parameter Setup Screen
To change any of the parameters, scroll through the menu using the arrow keys. When a
parameter is highlighted, press ENTER to make changes. Once you have finished editing all
the parameters, select F5 SAVE SETUP to store the new values.
Not used in the AT2500HM
LCD Backlight Off
Timer
Power Off Timer
Set the power off delay in minutes. This feature powers off the
AT2500HM when not in use. All active settings are saved at the
time of power off so that when the unit is powered on again, the
settings are exactly the same as when it was powered off. You
may continue to operate the unit by pressing any key, thus
restarting the countdown. Enter 999 to disable the feature.
Default value: 15 minutes
Video NTSC Output
(On/Off)
Toggle On or Off the Video NTSC output.
Video NTSC Timer
Set Video NTSC output off delay time in minutes.
Default value: Off
Default value: 15 minutes
Video NTSC on Boot
(On/Off)
Set Video NTSC output in the ON position when unit starts up
(boots).
Default value: On
Display Switch
Information (On/Off)
Company Identification
For remote control applications which use a test point switch
controlled by the AT2500HM. Provides a live view onscreen
according to the switch position.
Default value: On
Enter your company name in alphanumeric characters via the
keypad. Maximum 30 characters.
4-18
Chapter 4
Basic AT2500HM Functions
User Identification
Date Format
Enter your user name in alphanumeric characters via the
keypad. Maximum 30 characters.
Toggle between International and US date and time format.
Depending on the selection of US or International settings, the
temperature in the main menu will display in degrees Celsius
(international) or Fahrenheit (US). Also displays the time in 24hour (international) or 12-hour (US) format.
Default value: US
Date
Time
Set the current date on internal clock/calendar in the format
MM-DD-YYYY.
Set the current time on internal clock/calendar in the format
HHMMSS. Use the 24-hour clock (e.g. 1:00 pm is 13:00). The
time displays on a 12-hour clock if you select US date format.
Invalid Key Beep
(On/Off)
Toggle on or off a warning beep when an invalid key is pressed.
Power Off Beep (On/Off)
Toggle on or off a warning beep when the timer initiates the
shutdown process.
Printer Type (Epson/Hp)
(AT2500HMQ2 with
parallel port only )
Default value: Off
Default value: On
Toggle between an Epson compatible printer driver (for dot
matrix and inkjet printers) and a HP LaserJet printer driver.
The printer drivers embedded in your AT2500 contain a
minimal command set in order to increase efficiency and save
on disk space. The most common ink jet printers on the market
generally work well with the AT2500. However, your printer
may not be 100% compatible with the AT2500. If you do need
to purchase a printer for your analyzer, we recommend you
save a few traces in your analyzer and bring it to the store with
you to try it before making your purchase.
Default value: Epson
SRTB System Type
(AT2500R/AT2500H)
Lets you select the type of unit. For the AT2500HM series,
choose AT2500H.
Default value: AT2500H
Help Filename
File loaded into the AT2500HM containing the help text.
Default value: help.txt
Display (dBmV or
dBuV)
Toggle between dBmV and dBuV
Filter Mode
(Auto/Manual)
Toggle between automatic and manual filter selection. In order
to always use the automatic filtering function, set this field to
Auto. To always use the user-defined filtering option, set this
field to Manual. Filter settings are then restored at reboot.
Default value: dBmV
Default value: Manual
Chapter 4
Basic AT2500HM Functions
4.5.2
4-19
Defining Custom Screen Colors
The AT2500HM allows choosing different color schemes to make viewing the external VGA
monitor easier in different lighting conditions.
Figure 4-16: Color Setup Screen
To set up custom colors:
1.
First select which user is using the custom color scheme. You can create up to four custom
user color settings by pressing F3 USER 1 to F6 USER 4.
2.
Use the arrow keys to select the item that you want to edit. The nine editable screen
components are: Graphic Background, Graphic Line, Grid, Memory, Markers, Edge
Background, Edge Text, Editor Background and Editor Text. Select an item, and then use
the arrow keys to select the color.
3.
Once you have chosen a color for all of the items, press ENTER to save and exit color
setup mode. To exit without saving, press ESC and then ENTER at the prompt, or ESC
to remain in color setup mode until you are ready to save the setup and exit.
4-20
4.5.3
Chapter 4
Basic AT2500HM Functions
Setting up a Channel Plan
The Channel Plan includes a directory of several channel plan files that you can edit and
customize.
Figure 4-17: Channel Plan File Menu
Managing Channel Plan Files
From the Channel Plan directory screen, you can also edit, add, set as default or delete a
channel plan file. Highlight a channel plan file and then select one of the following keys:
Softkey
Action
F1 EDIT SELECTED FILE
Opens a new menu with options for editing a file. You
can also highlight a file and press ENTER to access
this menu.
F2 SET AS DEFAULT
Selects (or deselects) a default file. A checkmark
appears next to the default channel plan file used
during tests.
F3 ADD NEW FILE
Creates a new channel plan file.
F4 DELETE SELECTED FILE
Erases a channel plan file from the AT2500HM.
If you selected F1 EDIT SELECTED FILE from the channel plan directory, you can now edit
a particular plan within the file. Highlight a channel plan, and select one of the following keys:
Softkey
Action
F1 EDIT SELECTED PLAN
Opens a new menu with options for editing a plan.
You can also highlight a plan and press ENTER to
access this menu.
F2 SET AS DEFAULT
Selects (or deselects) a default plan. A checkmark
appears next to the default channel plan used during
tests
F3 ADD NEW PLAN
Creates a new channel plan. You must enter a name
for the plan.
Chapter 4
Basic AT2500HM Functions
4-21
F4 DELETE SELECTED PLAN
Erases a channel plan from the selected file.
F5 CHOOSE ANOTHER FILE
Returns to the previous menu so you can select a
different file.
F6 SAVE PLANS TO FILE
Saves edited plan or new plan to the channel plan file.
Editing or Adding a Channel Plan
The channel plan menu provides a summary of the channels in the selected plan, such as the
position, type, frequency and a selection of VITS parameters to indicate where particular test
signals are for most of the CATV tests available. If a checkmark appears in the TEST column,
then the channel is included in the automatic tests (autotest). In addition to standard TV or
digital channels, the channel line-up can also include leakage detector pilot signals or data
carriers. Note that it may be easier to edit an existing channel plan, by adding or deleting some
channels and editing other channels as required (see below, F2 DUPLICATE CURRENT
PLAN AS).
Figure 4-18: Adding or Editing a Channel Plan
If you selected F1 EDIT SELECTED PLAN from the channel plan file, you can now edit a
particular channel, save the entire plan under another name (duplicate), add and remove
channels, etc. Choose one of the following options:
Softkey
Action
F1 EDIT SELECTED CHANNEL
Opens a new menu with options for editing a channel.
You can also highlight a channel and press ENTER to
access this menu.
F2 DUPLICATE CURRENT
PLAN AS
Saves the current plan under a new name. You must
enter a name. This is the recommended method for
defining a channel plan. You can then edit the individual
channels (see above) as required.
F3 ADD NEW CHANNEL
Creates a new channel that is added to the line-up.
F4 DELETE SELECTED
CHANNEL
Erases a channel from the line-up.
F5 CHOOSE ANOTHER PLAN
Return to the previous menu so you can select a different
plan.
F6 SAVE PLANS TO FILE
Saves the edited plan or new plan to the channel plan
file.
4-22
Chapter 4
Basic AT2500HM Functions
If you selected F1 again, EDIT SELECTED CHANNEL, from the channel plan menu, you can
now edit the channel’s parameters. Using the arrow keys, highlight each parameter and press
ENTER to edit it. Depending on the parameter, you may be able to toggle between accepted
values using the ENTER key, or you may be able to enter your own values using the
alphanumeric keypad. Note that the list of parameters is context-sensitive: for example, if you
are defining a digital channel, only options for digital channels appear in the list.
Field
Data Range
Default value
4 digit alphanumeric
Number
Name
20 digit alphanumeric
Type
Analog, Digital, Other
Analog
Test
Checkmark/no checkmark
No checkmark
Once you select the type (analog, digital or other) the remaining fields vary as shown in the
following pages.
FOR ANALOG CHANNELS (TYPE=ANALOG):
Field
Data Range
Fwdrev
Forward, Reverse
Video carrier freq
5 to 1500 MHz
Default value
Forward
55.25
Audio carrier freq offset
4 to 8 MHz
4.5
Audio carrier2 freq offset
4 to 8 MHz
0
Audio carrier2 bw
0 to 2 MHz
0
Audio 2 type
None, FM, Digital
None
Channel width lower
-2 to -1 MHz
-1.25
Channel width upper
4 to 6.75 MHz
4.75
Modulation
NTSC-M, PAL-B, PAL-G/H, PAL-I,
PAL-M, PAL-N, SECAM-B, SECAMG/H, SECAM-K/L, Unknown
NTSC-M
Scrambling
None, Vertical, Horizontal
None
Hum measure in auto test
Checkmark/no checkmark
No Checkmark
Hum
CW, Video
Video
Hum freq
50, 60 Hz
60
CCN measure in auto test
Checkmark/no checkmark
No Checkmark
CCN gated line
7 to 35
15
CCN gated field
Field 1, Field 2, Both
Field 1
CCN freq. offset
-9.99 to 9.99
2
Video noise bw
4 to 6 MHz
4
CTB gated line
7 to 35
15
CTB gated field
Field 1, Field 2, Both
Field 1
CTB freq. offset
-9.99 to 9.99
0
CSO gated line
7 to 35
15
CSO gate field
Field 1, Field 2, Both
Field 1
CSO freq. off low1 tag
Checkmark/no checkmark
No Checkmark
CSO freq. off low1 value
-9.99 to 0 MHz
-1.25
CSO freq. off low2 tag
Checkmark/no checkmark
Checkmark
CSO freq. off low2 value
-9.99 to 0 MHz
-0.75
CSO freq. off up1 tag
Checkmark/no checkmark
Checkmark
Chapter 4
Basic AT2500HM Functions
4-23
Field
CSO freq. off up1value
Data Range
0 to 9.99 MHz
Default value
0.75
CSO freq. off up2 tag
Checkmark/no checkmark
Checkmark
CSO freq. off up2 value
0 to 9.99 MHz
1.25
IRC line
7 to 35
19
IRC field
Field 1, Field 2
Field 1
IRC signal type
Multiburst, GCR, Cable sweep, sinx/x
Multiburst
IRC freq. 1
.5 to 5 MHz
0.5
IRC freq. 2
.5 to 5 MHz
1.25
IRC freq. 3
.5 to 5 MHz
2.0
IRC freq. 4
.5 to 5 MHz
3.0
IRC freq. 5
.5 to 5 MHz
3.6
DOM measure in auto test
Checkmark/no checkmark
No Checkmark
DOM line
7 to 35
17
DOM field
Field 1, Field 2
Field 1
DOM signal type
Multiburst, NTC-7, Composite TX
Multiburst
Video diff gain/phase line
7 to 35
17
Video diff gain/phase field
Field 1, Field 2
Field 1
Video diff gain/phase sig.
type
NTC-7, Composite TX, Full line 5 steps,
Full line 10 steps, Full line ramp
NTC-7
Video YC line
7 to 35
17
Video YC field
Field 1, Field 2
Field 1
Video YC signal type
NTC-7, Composite TX, Sin square pulse
& bar
NTC-7
Video SN line
7 to 35
17
Video SN field
Field 1, Field 2
Field 1
Video SN signal type
NTC-7, Composite TX, Sin square pulse
& bar
NTC-7
Figure 4-19: Analog Channel Setup
4-24
Chapter 4
Basic AT2500HM Functions
FOR DIGITAL CHANNELS (TYPE=DIGITAL):
Field
Data Range
Default value
Fwdrev
Forward, Reverse
Forward
Center freq
5 to 1500 MHz
555
Channel width
1 to 10 MHz
6
Modulation
QAM64, QAM256
QAM64
Symbol rate
5 - 7 MS/s
5.056941
Polarity type
Auto, Normal, Reverse
Normal
J83 annex
A, B, C, None
B
Figure 4-20: Digital Channel Setup
FOR OTHER CHANNELS (TYPE=OTHER):
Field
Data Range
Default value
Fwd/rev
Forward, Reverse
Forward
Center freq
5 to 1500 MHz
88.1
Channel width
0.1 to 10 MHz
0.2
Modulation
QPSK, FSK, BPSK, CW,
VSB-AM,
FM,
CDMA,
Unknown, QAM 16, QAM 32
FM
Symbol rate
0 to 99999999 S/s
0
Burst
Burst, Continuous
Continuous
TDMA length
0 to 999999 ms
0
TDMA repeat rate
0 to 999999 ms
0
Once you have made all necessary changes, press F6 SAVE PLANS TO FILE to record your
changes.
Chapter 4
Basic AT2500HM Functions
4.5.4
4-25
Setting up Remote Switches
The AT2500HM can control broadband switches such as the VeEX AT1600 series switches.
Switches from other vendors may also be compatible with the AT2500HM. Contact your
VeEX representative for more information. The AT2500HM can only control the switches on
its serial COM port.
To set up remote switches, go to the setup screen (Figure 4-14 on page 4-16) and press F4
SWITCH SETUP. Use the arrow keys to highlight a field and then edit its value. The default
values are shown in the following table:
Field
Range
Default
Serial Port (COM1–COM4)
COM1, COM2, COM3,
COM4
COM2
Baud Rate (2400–115200)
2400, 9600, 14400, 19200,
38400, 57600, 115200
This value varies according
to switch type.
No Switch, VeEX, Elect.
TPS, Custom 1, QEC SRR
No Switch
Total number of RPTP (1..256)
1 to 256
16
Master Group Start
1 to 65535
1
Switch Type
Press F5 to save the setup.
Figure 4-21: Remote Switch Setup
4.5.5
Activating the NTSC Output
The AT2500 includes a baseband NTSC signal representative of the actual spectrum analyzer
screen display. This NTSC signal can be sent to a TV or a channel modulator.
On the AT2500HM, choose the SETUP icon from the main menu, and then select F6 NTSC
OUT ON/OFF. You can now toggle between an active (ON) or inactive (OFF) NTSC output.
Note that this feature can also be enabled or disabled through the general preferences menu.
See section 4.5.1, Choosing General Operating Parameters on page 4-17.
5-1
Chapter 5
USING THE SPECTRUM
ANALYZER FUNCTIONS
The Spectrum Analyzer Module is a standard feature on models HM, and HMQ of the
AT2500HM series analyzers. This module offers full signal analysis functionality over the
5 MHz to 1.5 GHz range. This chapter covers all spectrum analyzer functions accessed through
the Spectrum Analyzer icon and the Frequency Counter icon on the main menu. For additional
features used to test cable TV signals, see Chapter 6, CATVPAK Automated CATV
Measurements.
Figure 5-1: Spectrum Analyzer Screen
5.1
Spectrum Analyzer Menus
To access the spectrum analyzer functions, return to the main menu and select the
SPECTRUM ANALYZER icon. Once in this mode, use the five main menu keys listed
below to access softkey control menus. Press ESC to bring up a secondary softkey menu of
modes that can be directly accessed using the same softkeys.
Button
Softkey Menus
Button
Softkey Menus
<]>
<\>
<‘>
F1 CENTER FREQUENCY
F2 VIDEO CARRIER
F3 AUDIO CARRIER
F3 ALL CARRIERS
F6 FILTER ON, OFF, AUTO
F1 MAX SPAN
F2 ZERO SPAN
F3 RESOLUTION BANDWIDTH
F4 SWEEP TIME
F5 VIDEO BANDWIDTH
F6 FREE RUN, PWR LINE, TV
FRAME
F1 NO AVERAGE
F2 AVERAGE 1
F3 AVERAGE 2
F4 PEAK HOLD
<[>
F1 ATTEN.
F2 REFERENCE LEVEL
F3 VERTICAL SCALE
F4 REFERENCE OFFSET
<;>
F1 V1 MARKER
F2 V2 MARKER/NOISE
F3 H1 MARKER
F4 H2 MARKER
F5 V1 > CF
F6 V2 > CF
5-2
Chapter 5
Using the Spectrum Analyzer Functions
5.2
Spectrum Analyzer Instrument Settings
5.2.1
Tuning to a Frequency
The < ] > button calls up the frequency tuning functions of the AT2500HM spectrum analyzer.
The frequency tuning functions are automatically called up whenever accessing a mode that
may require tuning.
The frequency tuning functions offer four ways to select a frequency:
F1 CENTER FREQUENCY. Enter a center frequency value in MHz either through the
keypad or by using the arrow keys.
F2 VIDEO CARRIER. Enter a TV channel reference (as per the active channel plan) to
automatically tune to the frequency that coincides with the video of the channel.
F3 AUDIO CARRIER. Enter a TV channel reference (as per the active channel plan) to
automatically tune to the frequency that coincides with the audio of the channel.
F3 ALL CARRIERS. Select from additional carriers programmed in the channel plan such as
FM radio, and alignment carriers.
Press ENTER to confirm your selection.
5.2.2
Using the Filters
The frequency tuning functions include an option for activating filters.
Figure 5-2: Using the Filters
Note: It is recommended to use filters in automatic mode for most measurements.
To activate a filter:
1.
Press < ] > to access the frequency tuning functions.
2.
Press F6 FILTER ON, OFF, AUTO to access the filter menus.
3.
Press F1 and select ON. An arrow symbol appears next to the active choice. Note that if
you select OFF or AUTO, you can skip to step 0.
4.
Select the softkey that corresponds to the type of filter you want to use:
F2
LOW PASS FILTER. Choose from one of the 7 cutoff frequencies: 45, 88, 174,
280, 370, 460, or 550 MHz.
Chapter 5
5-3
Using the Spectrum Analyzer Functions
F3
F4
5.
HIGH PASS FILTER. Choose from one of the 7 cutoff frequencies: 35, 78, 164,
270, 360, 450, or 540 MHz.
BAND PASS FILTER. Select a combination of low and high pass filters.
Press ENTER or use the arrow keys to scroll through the choices within each filter type.
6. Once you have made your choice, press F5 SAVE SETUP to activate the filter and return
to the spectrum analyzer. To cancel your changes, press F6 RESET DEFAULTS to use
the default filter settings.
Note:
When the filters are turned on, the minimum attenuator value is 5 dB.
Note:
The appearance of an “S” symbol at the bottom left of the screen above the VeEX
Telecom logo indicates saturation (i.e. an overload condition on the analyzer).
Attenuation and/or span adjustments should be made to reduce the overall input power
into the analyzer. Once the appropriate adjustments are made, the “S” symbol will
disappear.
For more information on using filters, see the VeEX application note AP-AT10-012-A, Proper
Alignment of Tunable Bandpass Filters for Noise and Distortion Testing, on our website:
www.VeEXtelecom.com.
5.2.3
Setting the Span
The < \ > button calls up the span-related functions. Frequency spans are variable from a
maximum span of 1500 MHz to a minimum span of 100 kHz. Zero span mode is also
available.
To set the span:
1.
Press < \ > to access the span functions.
2. By default, you are prompted to enter a value in MHz and press ENTER. The arrow keys
also increment the span settings.
Up/Down Arrow Key
Span
Left/Right Arrow Key
Increments
Increments
<10 MHz
0.1 MHz
1 MHz
10-1000 MHz
1 MHz
10 MHz
>1000 MHz
10 MHz
100 MHz
You may also choose one of the softkey shortcuts:
• press F1 MAX SPAN to set the AT2500HM to its full 1-1500 MHz span or
• press F2 ZERO SPAN to access the AT2500HM’s built-in AM/FM demodulator.
To detect aural signals in zero span mode, tune to a specific frequency and activate the
audio demodulator by pressing F2 LOG AM FM. Toggle between log scale, AM
detector with percent of modulation scale and FM detector with deviation scale in kHz.
The AT2500HM has no speaker, so the F3 VOLUME softkey has no effect.
For more information on the hum, depth of modulation and frequency response options
that are available in zero span mode, see section 6.3, Distortion Measurements on page
6-5.
5-4
Chapter 5
Using the Spectrum Analyzer Functions
Figure 5-3: Zero Span Mode
5.2.4
Setting the Resolution Bandwidth, Sweep Time and Video
Bandwidth
The AT2500HM’s intermediate frequency (IF) filters affect the way signals appear on the
display. As the filter bandwidth changes (resolution bandwidth), the width of the displayed
response also changes. The wider a filter is, the wider the signal appears on the screen. One
way to determine if the resolution bandwidth (RBW) is set wide enough to respond fully to the
input signal is to increase the filter and watch until the amplitude no longer increases.
Span affects the RBW and video bandwidth (VBW) settings. For viewing a TV channel, the
RBW and VBW should be set to 300 kHz and 100 kHz respectively, or wider if the span is
greater than 10 MHz. By default, the AT2500HM automatically adjusts the RBW, the sweep
time and the VBW according to the span selected (autocoupled). In automatic mode, the letter
(A) appears in the display at the top of the screen, next to each of the three parameters. The
letter (M) is displayed next to the parameter to indicate that it has been changed manually. To
reset the parameter to its automatic value, press its softkey again. Note that if you manually
change the RBW, VBW and SWT settings to values that are incompatible for an accurate
measurement, an “uncal” message appears below the VeEX logo at the bottom left of the
screen.
To set up the resolution bandwidth, sweep time and video bandwidth, press < \ > and select
values for the following:
F3 RESOLUTION BANDWIDTH. Selects the IF filter setting for a measurement. To
change the bandwidth manually, press F3 and use the arrow key to select one of the
accepted values. The horizontal time and the video bandwidth adjust automatically to the
appropriate values for the bandwidth selected. The letter (M) is displayed next to the
resolution bandwidth parameter to indicate that it has been changed manually. If desired,
press F3 again to reset the resolution bandwidth to its automatic value.
Accepted values: 10, 30, 300 or 1000 kHz.
F4 SWEEP TIME. Selects a sweep time in milliseconds (ms), either via the keypad or by
using the arrow keys. If the sweep time is too slow for the bandwidth, the message “uncal”
appears to indicate that insufficient data is available to display the waveform properly.
In order to display an accurate measurement, sweep time is automatically set to a value
that is inversely proportional to the square of the resolution bandwidth. Press F4 again to
reset the sweep time to its automatic value.
Chapter 5
5-5
Using the Spectrum Analyzer Functions
Accepted values: 2, 4, 10, 20, 30*, 50, 100, 200, 500, 1000, 2000, and 5000 ms. Note that
30 ms sweep time is only available with spans of 1000 MHz or more.
F5 VIDEO BANDWIDTH. Selects a video bandwidth in kilohertz (kHz), either via the
keypad or by using the arrow keys.
Accepted values: 10, 100 or 1000 kHz.
Examples
Figure 5-4: Signal Measurement with RBW of 10 kHz
Figure 5-5: Signal Measurement with RBW of 30 kHz
5-6
Chapter 5
Using the Spectrum Analyzer Functions
Figure 5-6: Signal Measurement with RBW of 300 kHz
Figure 5-7: Signal Measurement with RBW of 1000 kHz
Chapter 5
5-7
Using the Spectrum Analyzer Functions
5.2.5
Setting the Amplitude
To set up the amplitude, select values for the following:
F1
ATTENUATOR. Adjusts the variable 65-dB attenuator. Select input attenuation by
increasing or decreasing in steps of 5 dB.
F2
REFERENCE LEVEL. Sets top of the screen reference level in steps of 1 dB.
F3
VERTICAL SCALE. Selects one of vertical scale options: 10 dB, 5 dB or
2 dB/div.
F4
REFERENCE OFFSET. Sets reference level offset value from -40 to +40 dB. All
level readings will automatically be compensated. This function is useful when
working with amplifiers or other equipment that have test points. All that has to be
done for test point (TP) compensation is to enter the value of that TP.
5.2.6
Multiple Trace Display
The AT2500 displays 500 data points per trace, and can display up to four traces
simultaneously. Each trace is displayed in a different color that has been pre-selected to
maximize the contrast with the background color, and the other traces.
In indoor conditions the trace colors are as follows:
Trace 1: Yellow
Trace 2: Blue
Trace 3: Pink
Trace 4: Green
In outdoor conditions the trace colors are as follows:
Trace 1: Black
Trace 2: Blue
Trace 3: Pink
Trace 4: Green
Press TRACE to access the signal processing choices, and select one of the following options:
F1
NO AVERAGE. With this method, the AT2500’s averaging function is off.
Data appears as it is captured.
F2
AVERAGE 1…50. The AT2500 displays the average value of the user selected
number of captured traces. The user selects a value between 1 and 50.
F3
DETECT. The AT2500 selects between positive, negative, or sample detector
mode.
F4
PEAK HOLD. The AT2500 displays the highest value for each data point.
MIN HOLD. The AT2500 displays the lowest value for each data point.
F5
TRACE. Toggles trace on/off.
F6
TRACE. Selects the specified trace number to edit. Trace is 1, 2, 3 or 4.
When the AVERAGE 1…50 function key is pressed (F2), a prompt for the number of averages
will appear as AVG LENGTH on the bottom right hand portion of the screen. The number
selected between 1 and 50 inclusive, will be retained if one exits the spectrum analyzer mode
and later returns.
The default settings for Traces 1 through 4 are shown below
TRACE
AVERAGE
DETECTOR
PEAK HOLD / MIN HOLD
TRACE
ON/OFF
1
NO AVERAGE
POSITIVE
OFF
ON
2
AVERAGE=10
SAMPLE
OFF
OFF
3
NO AVERAGE
POSITIVE
PEAK HOLD
OFF
4
NO AVERAGE
NEGATIVE
MIN HOLD
OFF
5-8
Chapter 5
Using the Spectrum Analyzer Functions
Figure 5.8 below shows how four traces turned on simultaneously may appear on the screen.
Trace 2
Trace 3
Trace 1
Trace 4
Figure 5-8: Multiple Trace Display
Note:
When two or more traces are superimposed on each other, different color combinations
may appear. To differentiate one trace from another will require different settings to be
applied to the traces. Traces may alternatively be turned on and off as required to view
only the traces of interest. This will help in minimizing the activity on the screen.
Pressing the PRESET button or turning the unit on and off will reset the traces to their
default values.
Chapter 5
5-9
Using the Spectrum Analyzer Functions
5.2.7
Using the Markers (Vertical, Horizontal, and Tilt)
Two vertical markers and two horizontal markers can be used to set level and frequency
references. The vertical V1 and V2 markers indicate the frequency and respective level. When
viewing multiple traces, the user has the ability to select the trace for which the vertical markers
will be applied. In addition to the horizontal and vertical markers, the AT2500 series analyzer
includes a tilt marker, which assists cable operators in assessing and aligning their cable
systems.
Vertical Marker Menus
F1
MKR V1. Indicates which trace the first marker will function on. The 5 options
are 1, 2, 3,4, or no arrow (off). The default is no arrow (off). The color of the
vertical marker V1 is the same as the trace against which it is applied.
F2
MKR V2. Indicates which trace the second marker will function on. The 5
options are 1, 2, 3,4, or no arrow (off). The default is no arrow (off). The color of
the vertical marker V2 is the same as the trace against which it is applied.
F3
MKR V2. Selects V2 as a level or noise marker.
F4
V2 MODE. Indicates V2 mode of operation with three options FREE, DELTA,
and TRACK. The FREE option is the normal operation, where V2 can be
moved independently of V1. The DELTA option allows the user to lock V2 to
V1 at a specific frequency delta or offset so that both markers move together.
The TRACK option locks V2 to V1 at whatever offset is currently set
F5
PEAK. Changes to peak search menus. Turns on V1 and searches to positive
peak.
F6
MORE 1/3. Goes to the horizontal markers screen (2/3).
Peak Search Marker Menus
F1
PEAK. Toggles between Positive or Negative peak search. The arrow indicates
current mode. If V1 is off, turns V1 on. Default is Positive, but will remember
last used setting.
F2
NEXT PEAK. Finds next highest/lowest peak on the screen.
F3
NEXT PEAK RIGHT. Finds next peak to the right.
F4
NEXT PEAK LEFT. Finds next peak to the left.
F5
V1=>CF. Tunes center frequency to vertical marker 1.
F6
V2=>CF. Tunes center frequency to vertical marker 2.
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Chapter 5
Using the Spectrum Analyzer Functions
Figure 5.9 below shows the first of three marker menus. The measurements shown are for the
V1 and V2 markers applied to the second trace of a multiple trace display.
Trace 2
Figure 5-9: Vertical Marker Menu
Figure 5.10 below shows the peak search menu as chosen from within the vertical marker
menu. By pressing the F2 menu item (NEXT PEAK) the next highest peak on the screen is
selected. The frequency and associated level is displayed below, and represented via the
marker. The marker is moved as per the menu item selections.
Figure 5-10:Peak Search Marker Menu
To set the vertical markers:
1.
Press < ; > to call up the marker menu, then choose one of the following options:
F1
V1 MARKER. Sets vertical marker 1 to trace 1. Press F1 in succession to scroll
through the multiple traces if they are active.
F2
V2 MARKER. Sets vertical marker 2 to trace 1. Press F2 in succession to scroll
through the multiple traces if they are active.
2.
Select F3 to operate V2 as a level or noise marker.
Chapter 5
5-11
Using the Spectrum Analyzer Functions
3.
Select F4 to operate V2 in either the FREE, DELTA or TRACK modes of operation.
4.
Use the arrow keys or the rotary knob to position the marker(s). Marker values will remain
current until new data is entered.
5.
To automatically tune the center frequency to vertical marker 1 or vertical marker 2 ,
proceed to step 7, as these menu options are found in the horizontal marker menu.
6.
Press ESC to exit the marker menu and go back to the previous menu, or, to proceed to the
horizontal marker menu go to step 7.
7.
Press F6 to enter the horizontal marker menu.
Horizontal Marker Menus
F1
MKR H1. Sets the first horizontal marker (H1).
F2
MKR H2. Sets the second horizontal marker (H2).
F3
(UNUSED)
F4
V1=>CF. Tunes center frequency to vertical marker 1.
F5
V2=>CF. Tunes center frequency to vertical marker 2.
F6
MORE 2/3. Goes to the tilt markers screen (3/3).
Figure 5-11 below shows the second of the three marker menus. The measurements shown are
for a typical multiple trace display where vertical and horizontal markers are activated.
Figure 5-11: Horizontal Marker Menu
To set the horizontal markers
1.
Press < ; > to call up the vertical marker menu, then press F6 once to enter the horizontal
marker menu.
2.
Press F1 to activate horizontal marker H1.
3.
Press F2 to activate horizontal marker H2.
4.
Use the arrow keys or the rotary knob to position the H1 and H2 markers as required.
5.
Press ESC to exit the horizontal marker menu.
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Chapter 5
Using the Spectrum Analyzer Functions
Tilt Marker Menus
F1
TILT MKR. Activates the tilt marker on or off.
F2
TILT MKR LOW FREQUENCY. Sets the low frequency reference value.
F3
TILT MKR LOW FREQUENCY LEVEL. Sets the level (in dBmV) of the low
frequency reference value.
F4
TILT MKR HIGH FREQUENCY. Sets the high frequency reference value.
F5
TILT. Sets the Tilt by using keypad or wheel/arrow combination to adjust the
slope.
F6
MORE 3/3. Goes back to the vertical marker menu (1/3)
Figure 5-12 below shows the tilt marker menu. The display highlights the spectrum between a
specified low and high frequency range and a specified tilt.
Figure 5-12: Tilt Marker Adjustment Menu
To set the tilt marker
1.
Press < ; > to call up the vertical marker menu, then press F6 twice to enter the tilt marker
menu. (or once to enter the tilt marker menu via the horizontal marker menu).
2.
Press F1 to activate the tilt marker from the default off position to the on position.
3.
Press F2 to set the low frequency reference value.
4.
Press F3 to set the low frequency level (in dBmV) reference value.
5.
Press F4 to set the high frequency reference value.
6.
Press F5 to set the desired tilt level (in dB) reference value.
7.
Press ESC to escape the tilt marker menu or F6 to return back to the vertical marker menu.
Chapter 5
5-13
Using the Spectrum Analyzer Functions
5.2.8
Selecting the Sweep Method
Press < \ > to access the sweep mode choices, and press F6 to select one of the modes. An
arrow symbol appears next to the active mode:
Free Run. In this mode, the AT2500HM continually scans and retraces the signal. The
scan-retrace cycle repeats indefinitely.
Pwr Line. In this mode, the AT2500HM scan-retrace cycle repeats at the power line
frequency, which is 60 Hz or 50 Hz depending on how the channel is defined in the
channel plan.
TV Frame. In this mode, the scan’s starting time repeats at the video frame rate, which is
29.97 Hz or 25 Hz depending on how the channel is defined in the channel plan.
The Pwr Line and TV Frame modes “freeze” the spectrum analyzer trace and display activity
related to power line applications or TV signals.
5.3
Using the Frequency Counter
The frequency counter measures frequencies and levels accurately for CW carriers, AM, FM or
TV channels. The counter displays frequency with a 10 Hz resolution.
Accuracy is provided through the stable 1-PPM reference time base. For example, the accuracy
when reading a frequency of 100 MHz is 100 x 1, which is equivalent to 100 Hz.
To access the frequency counter, return to the main menu and select the FREQ. COUNTER
icon. The AT2500HM always initiates an autocalibration sequence before entering this mode
for maximal accuracy.
See section 5.2, Spectrum Analyzer Instrument Settings on page 5-2 for information on
selecting a frequency to be measured.
Figure 5-13: Frequency Counter Menu
6-1
Chapter 6
CATVPAK - AUTOMATED
CATV MEASUREMENTS
The CATVPAK is a standard feature on models HM and, HMQ of the AT2500HM series
analyzers. It includes the following test functions:
• Digital Channel Power
• Hum
6.1
•
TV Channel
•
CCN, CSO, CTB
•
Multi-Carrier
•
In-Channel Frequency Response
•
Auto Test
•
Depth of Modulation
Digital Channel Power
The AT2500HM analyzer measures digital channel power by averaging the sum of power level
acquisitions across the desired measurement bandwidth.
To measure digital channel power:
1.
Select the DIGITAL CH POWER icon from the main menu.
2. Tune to the desired center frequency or channel to be measured. To do so, either:
• press < ] > and then use F1 or F2 to set the frequency. Press ESC to return to Digital
Channel Power mode. OR
• press F3 to access the spectrum analyzer, then press F1 to set the center frequency of
the channel to be measured. Press F8 to return to the digital channel power function.
3.
Press F1 to set the bandwidth of the channel to be measured. The default bandwidth is
6 MHz.
4.
Press F6 MEASURE to initiate the automatic measurement. The AT2500HM
automatically adds the power levels it reads at each acquisition point under the curve. The
number of acquisition points and the width of the RBW filter used depend on the
bandwidth you selected in step 0. The AT2500HM applies averaging and corrections to
the measurement, and displays in the channel power in dBmV and in dBm.
Figure 6-1: Digital channel power screen
6-2
Chapter 6
CATVPAK - Automated CATV Measurements
6.2
Frequencies and Levels
6.2.1
TV Channel Mode
TV Channel mode is used to measure modulated video and audio carriers as well as 4.5 MHz
intercarrier spacing with a 10 Hz display resolution.
To measure a TV channel:
1.
Select the TV CHANNEL icon from the main menu.
2.
Press the < ] > key .
3.
Tune to the desired frequency or TV channel by selecting one of the four softkeys:
F1
CENTER FREQ. Enter a frequency in megahertz.
F2
VIDEO CARRIER. Enter a channel number.
F3
AUDIO CARRIER. Enter an audio carrier.
4.
The AT2500HM begins reading the visual or aural levels and frequencies. The results
appear at the bottom of the screen along with the delta values.
Figure 6-2: TV Channel Mode
Chapter 6
6-3
CATVPAK - Automated CATV Measurements
6.2.2
Multi-carrier Mode
Multi-carrier mode is used to simultaneously measure the level of up to 6 carrier frequencies or
TV channel frequencies.
To measure multiple carriers:
1.
Select the MULTI-CARRIER icon from the main menu.
2.
Press the < ] > key .
3.
Choose the frequency by selecting one of the four softkeys:
F1
CENTER FREQ. Enter a frequency in megahertz.
F2
VIDEO CARRIER. Enter a channel number.
F3
AUDIO CARRIER. Enter an audio carrier.
F4
ALL CARRIERS. Enter a channel number for other types of carriers.
4.
Program the frequency for each of the bars in the display. When you first access this
screen, the bar on the left has a marker through it to indicate that it is active and ready to be
programmed. To switch between the display bars, press F5 SWITCH POSITION and
continue programming the rest of the display bars.
5.
Press the ESC key to exit programming mode and to begin reading the levels of the six
carriers.
Figure 6-3: Multi-carrier Mode
6-4
Chapter 6
CATVPAK - Automated CATV Measurements
6.2.3
AUTOTEST
The Autotest function is used to automatically test all tagged channels and frequencies in the
active channel plan. Please see section 4.5.3, Setting up a Channel Plan on page 4-20 to select
an active channel plan and tag the channels you want to include in the automatic test.
An entire headend can be scanned and measured within a minute, with level accuracy of
± 0.75 dB and a frequency accuracy of 1 PPM or 10 Hz.
In addition to the level and frequency measurements, the AT2500 can also perform Hum,
CCN, and Depth of Modulation tests on user selected channels. Within the channel plan, the
user selects all, or specific channels on which, some, or all three, of the additional tests will be
performed. In each case, the parameters specific to each of the measurements will be as
prescribed by the user in the channel plan.
Note that the carrier sweep option can be used to evaluate frequency response, but does not
offer the same accuracy in frequency response as a true sweep test.
Figure 6-4: Autotest Mode
To automatically test tagged channels:
1. To perform an autotest on levels only, or levels and frequencies, proceed to step 3. If one
or any of the following measurements (i.e. Hum, CCN, Depth of Modulation) are required
as part of the autotest, go to step 2.
2.
Change the field values for each channel within the channel plan by referring to section
Error! Reference source not found., Error! Reference source not found. prior to
initiating an autotest. The field values are described as follows;
a) Hum measure in auto test (field must be checked on to be tested)
b) CCN measure in auto test (field must be checked on to be tested)
c) DOM measure in auto test (field must be checked on to be tested)
Note:
When selecting the type of test in step 4, F3 must be selected to ensure the chosen
parameters are measured. Depending on the number of channels selected for which the
additional tests will be performed, measurement times may vary and may take on the
order of a few minutes to complete.
3.
Select the AUTOTEST icon from the main menu.
4.
Select the type of test:
F1
LEVELS ONLY
Chapter 6
6-5
CATVPAK - Automated CATV Measurements
F2
F3
F5
LEVELS AND FREQUENCIES
LEVELS, FREQUENCIES, & MORE
CARRIER SWEEP
5.
To stop the test, press F4. Use the rotary knob or arrow keys to view the measurements.
The measurements can be stored for later viewing or printing.
6.
To review the measured Hum, CCN, and DOM parameters press F6.
Figure 6-5: Autotest with Levels, Frequencies and More Results
6.3
Distortion Measurements
The AT2500HM’s software routines for measuring CATV distortions are designed for optimal
performance and follow all NCTA Recommended Practices for Measurements on Cable
Television Systems. To further enhance distortion measurement capabilities, the AT2500HM
series analyzers all have a built in pre-amp for better sensitivity. In addition, the AT2500HM
series analyzer includes built-in high/low pass, band selectable filters that can be programmed
to work together as bandpass filters that avoid input overloading and distortion or disruption of
measurement results.
There are two main ways to access distortion measure mode.
• From the main menu (press F7 ), select the HUM icon or CCN, CSO, CTB icon;
OR
• If you are already in spectrum analyzer mode, press ESC and then select F4
DISTORTION MEASURE.
6.3.1
Hum Modulation Measurement
To access hum measurement mode:
1.
2.
3.
4.
Select the HUM icon from the main menu.
Tune to the carrier frequency or TV channel that you want to test. To do so, press the < ] >
key , and then use the keypad to enter the channel, or press F1 CENTER FREQUENCY.
The AT2500HM automatically sets the attenuator before performing the test. If necessary,
you can manually set the input attenuator to view the carrier onscreen.
Press ESC to return to the Hum menu.
Identify the type of signal you are testing. To do so, press F4 to select either carrier wave
(CW unmodulated carrier) or video (modulated carrier). An arrow appears before the
6-6
Chapter 6
CATVPAK - Automated CATV Measurements
active selection. The AT2500HM automatically adjusts the instrument settings and
sequences the test.
You can now view the real-time hum measurements in dBc (decibels below reference carrier)
and in percentage.
Figure 6-6: Hum Modulation Measurement
For more information on hum measurements, see the VeEX application note
AP-AT10-010-A, HUM Measurements with the AT2000 Spectrum Analyzer, on our website:
www.VeEXtelecom.com.
Chapter 6
6-7
CATVPAK - Automated CATV Measurements
6.3.2
CCN, CSO and CTB measurements
Note:
Minimum carrier level for CCN measurements is 5 dBmV and 0 dBmV for CSO and CTB
measurements to ensure the most accurate results. Although the AT2500’s internal
filters can handle higher signal power, insufficient signal levels reduce the accuracy of
the measurement.
To access the CCN, CSO and CTB test menu:
1.
Select the CCN, CSO, CTB icon from the main menu, or press ESC if you are already in
the Spectrum Analyzer mode, then select F4 DISTORTION MEASURE and press F2
CCN, CSO or CTB. You are now in the distortion menu.
Figure 6-7: Distortion Measurements Menu and Results Screen
2.
Select single or combined mode by pressing F1 to mark your choice. An arrow symbol
appears next to your selection.
• Single mode measures the carrier for the selected parameter only. Use single mode
when you want to measure only one specific parameter.
• Combined mode takes all the measurements required for the CCN, CSO and CTB
test parameters. You can store the combined measurements as one record file.
Typically, the combined method is only used when the carrier (CW or video) is shut
down completely or if the gated method is used.
3. Select the in-channel or gated test method single by pressing F3 to mark your choice. An
arrow symbol appears next to your selection.
• In-channel requires the removal of either the carrier (typically for CTB
measurements) or its modulating signal (typically for CSO or CCN) at the system
headend. The AT2500HM prompts you through the measurement steps.
• Gated is a non-intrusive method that measures the channel noise of a selected line
during the vertical blanking period of the video signal. The gated method does not
require the removal of the RF carrier or modulation of the channel under test.
However, you need to take into account test conditions in order to ensure accuracy.
Possible causes of poor accuracy include a noisy quiet line selected for the gated test.
To avoid this problem, use a quiet line inserter. Quiet line inserters only allow for
accurate measurement of CSO or CCN. For gated combined or gated CTB only
measurements, use a line remover to shut down the carrier during the vertical interval.
This is the only way to measure CTB accurately while service is still active. Please
refer to the VeEX application note AP-AT10-009-A, Making Composite Triple Beat
Measurements Using the AT2000 Spectrum Analyzer, on our website at
www.VeEXtelecom.com.
6-8
Chapter 6
CATVPAK - Automated CATV Measurements
4.
CAUTION:
Set the Discrete Frequency Interference (DFI) to either ON or OFF by pressing F4. When
the setting is set to on, the user will observe higher acquisition times, as more measuring
points are being imposed across the whole band.
In order to avoid overloading the front-end input and causing the analyzer to generate
internal distortions, please ensure that the internal filters are set to the “auto” position.
Depending on the frequency selected for the distortion tests, the analyzer automatically selects
the closest low-pass filter below and the closest high-pass filter above the selected frequency.
This combination acts as a bandpass filter and thus reduces the total power entering the
analyzer to a non-overload condition. This ensures that the measurement results indicate the
analyzer measurement and not distortions the analyzer could have generated internally.
Minimum carrier levels for CCN measurements is 5 dBmV and 0 dBmV for CSO or CTB to
ensure the most accurate results. Although the AT2500HM’s internal filters can handle
excessive signal power, insufficient signal levels reduce the accuracy of the measurement.
5.
Press F5 SET MEAS. PARAMETERS to access the setup measurement window. Use the
arrow keys to select a parameter, and choose a value for each type of measurement. Note
that there are values already saved in the channel plan. By default, the AT2500HM uses
the saved values. However, you can use the softkey to change the settings for this test. The
changes are not stored in the channel plan and are erased from memory once the
AT2500HM is powered off. To make permanent changes, use the channel plan editor.
GATED TESTS
Field Select
At the specified center frequency or channel, sets the analyzer
to the correct video signal field where the test signal is expected
to be found. Press ENTER to choose field 1 or 2.
Line Select
At the specified center frequency or channel, sets the analyzer
to the correct video signal line where the test signal is to be
found. Choose a line from 7 to 35.
Figure 6-8: Distortion Measurement Setup
CCN TESTS
In-ch or gated
System Bandwidth
correction
Sets frequency offset from video carrier for noise correction
measurement.
Accepted values: -9.99 to 9.999 MHz. Typical value 2 MHz.
Noise bandwidth correction applied to the noise measurement
algorithm in CCN measurement.
Accepted values: 4.00 to 6.000 MHz. Typical value 4 MHz.
Chapter 6
6-9
CATVPAK - Automated CATV Measurements
CSO TESTS
Lower 1*
Lower 2*
Upper 1*
Upper 2*
CTB TESTS
In-ch and gated
Accepted values: -9.99 to 0.00 MHz. Typical value -1.25
Accepted values: -9.99 to 0.00 MHz. Typical value –0.75
Accepted values: 0.00 to -9.99 MHz. Typical value +0.75
Accepted values: 0.00 to -9.99 MHz. Typical value +1.25
* For each of these parameters, indicate whether you want to
measure the value. Toggle the “Measure” field on or off.
Accepted values: -9.99 to 9.999 MHz. Typical value 0.00
6.
When the changes have been made, press F5 to save the setup.
7.
Press F6 to begin the measurement. The results at the bottom of the screen include:
• the measured ratio (CCN, CSO or CTB, depending on selection) in dB
• the frequency in MHz
• the noise-near-noise (or beat-near-noise) correction factor used in the calculation.
Figure 6-9 below shows a measurement taken with the Discrete Frequency Interference (DFI)
turned on and subsequently turning on of the movable marker to observe other potential beat
products in the channel. The DFI marker is added to the screen and its associated measurement
results is shown on the bottom. The user scans the channel via the arrow keys or the rotary
knob to position the marker.
Figure 6-9: Combined Distortion Measurement with DFI on and Marker “on”
6-10
6.4
Chapter 6
CATVPAK - Automated CATV Measurements
In-Channel Frequency Response
The in-channel frequency response can be made with a vertical interval test signal (VITS). The
required test signal for proper measurement include any of the following:
• Cable multiburst
• Ghost canceling carrier (GCR)
• Wide band sweep
For ghost canceling carrier and wide band sweep signals, it is not necessary to set up the
multiburst packet frequencies. If a cable multiburst is used, however, make sure that the
analyzer multiburst packet frequencies match the test signal frequencies. Failure to set up the
multiburst packet frequencies may produce faulty measurement results since the AT2500HM
does not scan for these frequencies. An FCC multiburst is only valid for broadcasters and is not
supported by the AT2500HM series analyzer.
To measure in-channel frequency response:
1.
Select the IN-CHANNEL FREQ. icon from the main menu.
Figure 6-10: In-Channel Frequency Response
2.
3.
The AT2500HM starts the test automatically based on the values saved in the channel
plan. However, you can use the softkeys to change the settings for this test. The changes
are not stored in the channel plan and are erased from memory once the AT2500HM is
powered off. To make permanent changes, use the channel plan editor. To adjust the
AT2500HM’s settings:
F3
FIELD SELECT. At the specified center frequency or channel, press ENTER to
set the analyzer to the correct video signal field (1 or 2) where the test signal is
expected to be found.
F4
LINE SELECT. At the specified center frequency or channel, press ENTER to
set the analyzer to the correct video signal line (from 7 to 35) where the test signal
is expected to be found.
F5
MULTI-BURST SETUP. Define up to five multiburst packet frequencies based
on the test signal parameters.
To begin the test with the new settings, press F2 IN-CHANNEL RESPONSE.
Chapter 6
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CATVPAK - Automated CATV Measurements
4. At the end of the test, press F1 SEARCH MIN/MAX to position the horizontal markers to
find the peak and valley points and indicate the response figure in +/- dB.
6.5
Depth of Modulation
Depth of modulation is measured as the percentage of the total amplitude change of the carrier,
as the signal progresses from sync tip to peak white. You can measure depth of modulation on
a TV channel with a vertical interval test signal (VITS). A test signal transmitted on the VITS
of program video provides a reference to calibrate the video depth of modulation.
To measure depth of modulation:
1.
Select the DEPTH OF MOD icon from the main menu.
2. The channel’s field and line settings are already saved in the channel plan. By default, the
AT2500HM uses the saved values. However, you can use the softkeys to change the
settings for this test. The changes are not stored in the channel plan and are erased from
memory once the AT2500HM is powered off. To make permanent changes, use the
channel plan editor. Select the test signal as follows:
F3
FIELD SELECT. At the specified center frequency or channel, press ENTER to
set the analyzer to the correct video signal field (1 or 2) where the test signal is
expected to be found.
F4
LINE SELECT. At the specified center frequency or channel, press ENTER to set
the analyzer to the correct video signal line (from 7 to 35) where the test signal is
expected to be found.
The video depth of modulation appears at the bottom of the screen as a percent of
modulation. The graticule shows the same data in graphical format.
Figure 6-11: Depth of Modulation Measurement
7-1
TIME DOMAIN
MEASUREMENTS
Chapter 7
The Time Domain Module (TDM) is a standard feature on models HM, and HMQ of the
AT2500HM series analyzers.
This module is useful for observing burst levels, signal-to-noise (S/N) and total channel power
of upstream DOCSIS channels. It allows faster horizontal sweep times than the zero span mode
available with the standard spectrum analyzer module included with all AT2500HM series
analyzers.
To access the Time Domain Module, return to the main menu and select the TIME DOMAIN
icon.
Setting up the Display
7.1
If you have not already tuned to the frequency you want to observe, press F3 SPECTRUM
ANALYZER. This key provides a shortcut to the spectrum analyzer functions so that you can
set up the center frequency.
Figure 7-1: Setting up the Center Frequency and Markers
Tip:
If you are measuring DOCSIS cable modem bursts, you can obtain more information on
setting up the analyzer for accurate peak level measurements from the application note
“Upstream DOCSIS Signals” on our website at www.VeEXtelecom.com
1.
Press F8 to return to the Time Domain Module.
2.
Use the following softkey menus to set up the display.
F6
TEXT TOP MIDDLE BOTTOM. Press F6 to scroll through the choices for text
display: top, middle or bottom.
F1
SIGNAL BANDWIDTH (BW) CORRECTION. Enter a signal bandwidth
correction figure in megahertz (MHz) and press ENTER.
Accepted values: from 0.30 to 9.99 MHz, in steps of 0.01 MHz.
7-2
Chapter 7
Time Domain Measurements
F2
NOISE BANDWIDTH (BW) CORRECTION. Press F2 to toggle this feature on
or off. When active, this feature applies the AT2500HM’s internal correction factor
to the noise bandwidth. Noise measurements are available when the vertical
markers are used and vertical marker 2 (V2) is set to Noise.
The above softkey menus as well as the shortcut to Spectrum Analyzer mode are available
when you call up the Time Domain module, or when you switch between the Spectrum
Analyzer and Time Domain modes (toggle F8 key).
The analyzer is now ready to trigger on the signal. See section 7.2.
7.2
Setting up the Time and Trigger Functions
Press < \ > to access the time and trigger functions. The first three softkey menus provide
manual control of resolution bandwidth, horizontal time and video bandwidth. The fourth key
provides access to a series of menus for selecting trigger parameters such as the level, holdoff
and delay.
7.2.1
Resolution Bandwidth, Horizontal Time and Video Bandwidth
By default, the AT2500HM automatically adjusts the resolution bandwidth, the horizontal time
and the video bandwidth according to the span selected in the spectrum analyzer screens. In
automatic mode, the letter (A) appears in the display at the top of the screen, next to each of the
three parameters. You can, however, adjust these parameters manually depending on the data
you want to view. The letter (M) appears next to the parameter to indicate that it has been
changed manually. To reset the parameter to its automatic value, press its softkey again (F3, F4
or F5).
Use the following keys to adjust the measurement parameters:
F3
RESOLUTION BANDWIDTH. To change the bandwidth manually, press F3 and
use the arrow key to select one of the accepted values. The horizontal time and the
video bandwidth adjust automatically to the appropriate values for the bandwidth
selected.
Accepted values: 10, 30, 300 or 1000 kHz.
F4
HORIZONTAL TIME. Press F4 to select a sweep time in milliseconds (ms),
either via the keypad or by using the arrow keys. If the horizontal time is too long
for the bandwidth, the message “Undersampling” appears to indicate that
insufficient data is available to display the waveform properly.
Accepted values: 0.05, 0.10, 0.20, 0.50, 1.00, 2.00, 5.00, 10.00, 20.00, 50.00,
100.00, 200.00, 500.00 ms
F5
VIDEO BANDWIDTH. Press F5 to select a video bandwidth in kilohertz (kHz),
either via the keypad or by using the arrow keys.
Accepted values: 10, 100 or 1000 kHz.
Chapter 7
7-3
Time Domain Measurements
7.2.2
Triggering on a Signal
Press F6 TRIGGER to display the menus for setting up the trigger level, holdoff and delay.
You can also change the horizontal time from this menu.
Figure 7-2: Triggering on a Signal
The following softkey menus appear once you press F6:
F1
TRIGGER LEVEL. Selects the amplitude for triggering on a signal. Use the
keypad or the arrow key to choose the level. The trigger level is usually set at
the vertical midpoint of the waveform. Adjust as necessary to obtain a stable
display.
Accepted values: 1 dB steps over the 70 dB dynamic range.
F2
SLOPE + SLOPE –. Toggles between a trigger on the positive or negative slope
of the waveform (rising edge or falling edge). A diagonal symbol appears to
indicate which slope has been selected. When rising to the right, the
AT2500HM triggers on the positive slope or rising edge of the burst and will
position the rising edge of the burst completely on the left of the screen; when
falling to the right, the AT2500HM triggers on the negative slope or falling edge
of the burst.
F3
DELAY AFTER TRIGGER. Selects the delay that the AT2500HM waits after
triggering to capture and display the waveform on the screen. This allows you to
trigger on one signal and view another portion of the signal (usually at a lower
level) that appears later. On precisely repetitive signals, it allows triggering on
one burst and so that it can be viewed before the next one occurs.
Accepted values: 0.001 to 100.000 ms in steps of 0.001 ms.
F4
HORIZONTAL TIME. Selects a horizontal time in milliseconds (ms). Use
either the keypad or the arrow keys. If the horizontal time is too long for the
bandwidth, the message “Undersampling” appears to indicate that insufficient
data is available to display the waveform properly.
Accepted values: 0.05, 0.10, 0.20, 0.50, 1.00, 2.00, 5.00, 10.00, 20.00, 50.00,
100.00, 200.00, 500.00 ms
F5
HOLDOFF. Selects the delay that the AT2500HM waits before triggering
again. Adding a holdoff can help differentiate a given data event from a series of
similar events.
7-4
Chapter 7
Time Domain Measurements
Accepted values: 0.050 to 700.000 ms in steps of 0.001 ms.
F6
FREE RUN, CONT, SINGLE. Scrolls through the trigger mode choices (free
run, continuous and single). In free run mode, the AT2500HM continuously
captures data without triggering. In continuous mode, the AT2500HM
automatically repeats its trigger-arm acquisition cycle. In single mode, press
ENTER to re-arm for another single acquisition.
Figure 7-3: Adjusting the Horizontal Time
7.2.3
Zooming in on a Signal
The zoom feature automatically sets the horizontal time, based on the selected portion of the
signal. To select a portion of the signal, you must first position the vertical markers.
To zoom in on a signal:
1.
Press < ; > to display the marker menu.
2.
Set the two vertical markers to frame a portion of the signal:
• Press F1 to set the first vertical marker (V1) and enter the time either via the keypad
or by using the arrow keys.
• Press F2 to select the second vertical marker. The arrow symbol should appear next to
V2. Enter the time for the second marker, either via the keypad or by using the arrow
keys.
Chapter 7
7-5
Time Domain Measurements
Figure 7-4: Setting the Markers for Zooming
3.
Once you have positioned markers V1 and V2, press ESC then press F5 ZOOM to view
the selected portion of the signal in greater detail. Note that if you leave the markers at
their default values (beginning and end of horizontal time period), then pressing F5
ZOOM sets the display to the fastest horizontal time the analyzer can fit in the display
window based on the time spacing between the two vertical markers.
Figure 7-5: Zooming in on a Signal
8-1
Chapter 8
QAM 16/64/256 DIGITAL
MEASUREMENTS
The QAM Analyzer Module is a standard feature on the HMQ model of the AT2500HM series
analyzer.
The QAM Analyzer Module demodulates and measures various parameters of 16, 64 and 256
quadrature amplitude modulation (QAM) signals carried through the cable system. Several
types of measurements can be made using the built-in digital demodulator:
• Bit Error Rate (BER), Pre and Post Forward Error Correction (FEC)
• Modulation Error Ratio (MER) and Error Vector Magnitude (EVM)
• Group Delay
Display modes include:
• Constellation Display with zoom capabilities.
• Error Statistics Graph Display
• Adaptive Equalizer Display.
To access the QAM Analyzer Module, return to the main menu and select the QAM
ANALYZER icon.
8.1
Setting up the QAM analyzer
To access QAM mode, select the QAM ANALYZER icon from the main menu, or from
Digital Channel Power Mode, select F2 QAM ANALYZER.
Based on the selected frequency, assuming the QAM channel is defined in the channel plan, the
analyzer automatically selects 16, 64 or 256 QAM settings with the appropriate settings such as
symbol rate, polarity, Annex A, B or C, and so on.
Figure 8-1: 256 QAM Constellation Display
8-2
Chapter 8
QAM 16/64/256 Digital Measurements
1.
Tune to the center frequency of the digital signal that you want to test. The AT2500HM
auto-ranges the attenuator setting and polarity setting before locking on the signal and
performing the test.
To tune while in QAM analyzer mode, press the < ] > key . Select F1 CENTER FREQ
and enter a frequency. Once you have entered the frequency, press the ESC key to return
to the QAM menu.
2.
If the QAM channel is not already in the channel plan, select F5 SET QAM
PARAMETERS.
Figure 8-2: QAM Channel Setup Menu
Channel Center
Frequency
Enter a center frequency in MHz.
Standard Type
Select J83ANNEX A, J83ANNEX B, J83ANNEXC, NO FEC
DEC 6MHZ, NO FEC DEC 8MHZ, UPSTREAM QAM 16
Modulation Type
Select 16, 64 or 256 QAM.
Symbol
Defaults to correct value for modulation type: 2.560 for 16
QAM, 5.057 for 64 QAM and 5.360 for 256 QAM.
symbol rate range is from 1.000 to 7.000 MS/sec.
Polarity Type
Select Normal or Reverse polarity. Reverse is used with IF
signals from modulators (before up-conversion). Default setting
is Automatic.
Stat MER Threshold
Sets visual limit line on screen in statistical mode. Range is
20 dB to 40 dB.
Stat BER-PRE Thres.
Sets visual limit line on screen in statistical mode. Range is
1E-4 to 2E-8.
Stat BER-POST Thres.
Sets visual limit line on screen in statistical mode. Range is
1E-4 to 2E-8.
In-band Equalizer
Setup
Select Off, Freeze, Un-freeze, or Special
FFE Equalizer Length
Toggle between ON and OFF.
DFE Equalizer Length
Select 8, 12, 16, 20, or 24.
Output MPEG (ASI)
Toggle between ON and OFF to turn on/off transport stream
output on rear panel.
Chapter 8
8-3
QAM 16/64/256 Digital Measurements
3.
Once all QAM settings have been entered, select F5 SAVE SETUP to initialize the QAM
measurement with the current settings. If you want to cancel your choices and return to the
factory default values, press F6 RESET DEFAULTS.
The AT2500HM automatically optimizes the attenuator and polarity settings and starts
testing the digital signal in real time. The test begins with an attempt to lock onto a known
symbol rate, then the Forward Error Correction (FEC) function, and then tries to detect the
presence of an MPEG transport stream. Refer to the bottom of the screen for a
confirmation of the analyzer’s ability to properly demodulate the signal and provide all
possible measurement parameters.
Note:
The AT2500HQ can not decode bursty upstream QAM 16 signals because it requires a
constant carrier in order to lock on the signal. A transmitter capable of generating a
constant carrier such as a CM1000 with the USG (Upstream Signal Generator) module is
required.
Testing QAM signal quality
8.2
The AT2500HM displays certain signal quality statistics on the right side of the constellation
display. They are:
• Bit Error Rate (BER), Pre and Post Forward Error Correction, refreshed every second
• Modulation Error Ratio (MER)
• Error Vector Magnitude (EVM)
• Estimated Noise Margin (ENM)
For an explanation of each of these error measurements, please consult the following sections.
Note:
8.2.1
It is recommended that the pre-selection filters be set to AUTO for all QAM
measurements except when digital channel power is < 0 dBmV.
Pre and Post Bit Error Rate (BER)
BER measurements are done after digital decoding (Trellis decoding, de-randomization, and
de-interleave) but as well as before and after Reed-Solomon error correction. The AT2500HM
error correction mechanism detects all errors.
BER Pre-FEC
Bit Error Rate Pre-Forward Error Correction. Indicates all errors
found in the previous second. It is shown as the ratio of errored
bits to the total number of bits transmitted in the second.
BER Post-FEC
Bit Error Rate Post-Forward Error Correction Shows the ratio of
uncorrected errored bits in a one second period. These are the bits
that could not be corrected after the FEC circuits.
The pre-FEC BER is normally higher than the post-FEC BER. Typically pre-FEC BER
increases with noise input while post-FEC BER remains at 0 until it comes very close to losing
the FEC lock. At that point, it increases very rapidly. Disturbances other than pure noise, such
as burst interference, have a different effect.
BER is displayed in scientific notation. The more negative the exponent, the better the BER.
The AT2500HM has a range of 0 to 1.0 x 10-4.
Note:
In order to detect bit errors in a 16 QAM upstream signal, the transmitter must encode
the data with a known bit stream and Reed-Solomon error correction. The CM1000 with
USG transmits a pseudo random bit stream (PRBS) with the proper Reed-Solomon
encoding to allow pre and post errors to be detected and displayed.
8-4
8.2.2
Chapter 8
QAM 16/64/256 Digital Measurements
Modulation Error Ratio (MER)
MER is the best overall “figure of merit” measurement to determine 16/64/256 QAM signal
quality and can be used to help diagnose transmission impairments. MER indicates the ratio, in
dB, of average total signal power in the ideal constellation to average error power in the
constellation as received by the AT2500HM. The measurement includes error power due to
any particular type of impairment or any combination of impairments.
8.2.3
Estimated Noise Margin (ENM)
The ENM is an indication of the headroom of the system. It is calculated from the MER, taking
into account modulation type (16, 64 or 256 QAM), the symbol rate and the bandwidth. It
assumes noise disturbance only; other disturbances result in a false ENM. The headroom is
related to the critical operating level or 1E-8 uncorrected error rate, at which point artifacts are
visible in a picture during a digital video transmission or data retransmissions are necessary in
the case where a cable modem is used.
8.2.4
Error Vector Magnitude (EVM)
EVM is the measurement of modulation quality of the transmitted signal before the forward
error correction stage. EVM indicates how much interference or distortion is present on the
signal. If there is significant degradation on the signal, the constellation points (displayed
symbols) becomes unclear, i.e. scatter further from each of the target boxes or decision
boundary centers, and the decoder may not be able to reconstruct the received signal correctly.
8.3
Constellation Display
To activate the constellation display, press F1 to select Const.
Figure 8-3: Constellation display
The Constellation Display shows both the “I” (in-phase component) and “Q” (quadrature
component) values. Each location on the constellation is framed by decision boundaries. If the
signal falls within these boundaries, the correct data is received. The data is in error if it falls
Chapter 8
8-5
QAM 16/64/256 Digital Measurements
outside of its boundaries into adjacent location such as when the signal is affected by noise or
other interference.
The constellation display can be used to troubleshoot problems by helping to identify the type
of impairment and isolate the source. Significant degradations in the signals can be identified
including noise, coherent interference and transmission distortions as well as modulator
impairments such as I/Q imbalance or quadrature error. Visual examination of the constellation
can be a good first step for diagnosing signal disturbances. The following list includes the
characteristic visual effects of a few types of signal impairment:
8.3.1
Pure Thermal Noise
Appears as a cloud around the ideal point, getting lighter as it
expands.
Phase Noise
Appears as crescent-shaped constellation points, more apparent on
the outer edge, because of angular shift of the signal.
Coherent Distortion or
CW Interference
Appears as doughnut shaped constellation with points all over,
due to the sum of different frequency vectors (signal and
interference).
Amplifier Compression
Appears as shift toward center for the outer edge points. Because
it is more severe on large amplitude, it may be associated with
phase shift (AM to PM conversion).
Zoom Mode
The ZOOM function frames a part of the constellation for closer viewing.
Figure 8-4: Zoom Display
To activate the Zoom function:
1.
First select F6 MORE 1/2 to go to the second menu level.
2.
Press F3 ZOOM to activate the zoom function. Use the arrow keys to move the frame to
any one of the corners of the constellation.
8-6
Chapter 8
QAM 16/64/256 Digital Measurements
3.
8.3.2
Press ENTER to select the frame for zooming. QAM 64 has one level of zoom (from 64
to 16) and QAM 256 mode has two levels of zoom (256 to 64 to 16). Press ESC to zoom
out. To toggle on or off the grid display, press F5 GRID ON/OFF.
Symbol Display Settings
In constellation display mode, you can set select from three modes that determine the number
of symbols displayed at any time.
To access the symbol display settings options:
8.4
1.
From the QAM constellation display, press < ‘ >.
2.
Select one of the display settings:
F1 CONTINUOUS. In this mode, the AT2500HM constantly populates the
constellation display. It plots every symbol on the screen until stopped. There is no
limit to the number of symbols that are displayed in this mode.
F2 CYCLIC. In this mode, the AT2500HM plots the number of symbols specified in
the Sample Length field and then clears the screen and starts over.
F3 TIME FILTER. In this mode, the AT2500HM plots the number of symbols
specified in the Sample Length field and then uses a first in/first out (FIFO) function
to clear the oldest symbols and plot new symbols. The number of symbols displayed
on screen is always the same.
F4 SAMPLE LENGTH. Sets the number of symbols shown before clearing symbols
from the constellation display.
Statistical Graph Display
Figure 8-5: Statistical Graph Display
In addition to constellation analysis and the MER-EVM-ENM measurements, the AT2500HM
can gather and store statistics for a period of 1 to 60 minutes. With the VeEX WinQAM
remote control software, the AT2500HM can provide up to seven days of real-time
acquisitions, with a 1-second resolution.
Chapter 8
8-7
QAM 16/64/256 Digital Measurements
1.
To activate the statistical display, use the F1 key to select STAT.
2.
Press F3 key to select the desired acquisition period (1-60 minutes) in local mode.
3.
To begin capturing data, press F4 to start gathering statistics. The AT2500HM displays
four time markers for the following events:
ES
Errored second. Indicates the measurement seconds where there was at least
one packet with an uncorrected error (post-FEC).
SES
Severely errored second within each measurement second. This means that the
ratio of errored packets to transmitted packets is higher than the user-defined
threshold (from 1E-4 to 1E-2).
FLS
Frame loss seconds. Indicates the number of measurement seconds where
there was at least one frame lock loss.
UNAV
Unavailability time. Indicates that there has been at least 10 consecutive
severely errored seconds.
The AT2500HM dynamically updates the graph as it gathers new data for the MER-EVMENM as well as the ES, SES, FLS and Unavailability time markers. At the end of the userdefined period, the AT2500HM saves all measurements so that they can be viewed as a global
data set or viewed in detail.
The recorded measurements for BER (Pre and Post) represent the total period. However, during
the measurement period, the AT2500HM displays the values dynamically, second per second.
8.5
Adaptive Equalizer Display
To activate the adaptive equalizer display, use the F1 key to select EQUAL.
The AT2500HMQ can display the coefficients of the equalization filter, updated every second.
This feature can be used to diagnose bandpass distortion (gain tilt, reflections).
There are three different displays in the equalizer screen:
• a bar graph showing the 32 coefficients: 8 Feed-Forward Equalizers (FFE) and 24
Decision Feedback Equalizers (DFE). The eighth coefficient is the main signal path,
so it is normally very close to 0 dB (unity gain).
• a frequency response graph (from +5 to -3 dB) over the defined channel bandwidth.
• a group delay graph showing the delay in nsec (from +50 to –30 nsec) across the
channel bandwidth.
8-8
Chapter 8
QAM 16/64/256 Digital Measurements
Figure 8-6: Equalizer Display in QAM Analyzer
See section 8.1, Setting up the QAM analyzer on page 8-1 to select the settings for the various
equalizers (i.e. In-band, FFE and DFE).
8.5.1
Frequency Response Display
The frequency response graph can be viewed independently from within the Equalizer Display
by using the F3 key to select FRQ RSP.
Figure 8-7: Frequency Response in Equalizer Display
In this mode, vertical and horizontal markers are available to perform specific measurements.
The above figure for frequency response shows horizontal markers H1 and H2 used to measure
the peak to valley of the frequency response plot.
Chapter 8
8-9
QAM 16/64/256 Digital Measurements
8.5.2
Group Delay Response
The group delay response can be viewed independently from within the Equalizer Display by
using the F3 key to select GRP DEL.
Figure 9-8; Group Delay Response in Equalizer Display
In the above group delay figure, vertical V1 and V2 markers indicate the frequency and delay
at each point. When both V1 and V2 are used, the delta values in both frequency and time are
displayed. Additionally the slope of the curve between marker points is indicated in ns/MHz.
8.5.3
QAM Normalization
The AT2500HM allows multiple QAM Normalization tables to be saved in memory. This is
useful when the AT2500HM is used as a test instrument to characterize QAM signatures such
as in an equipment manufacturing application. For additional information on this application of
the AT2500HM please contact VeEX Telecom Broadband.
This feature is typically not used in regular cable TV applications.
Note:
Storing a QAM normalization table will override the default settings and can severely
effect performance if used improperly.
To activate the QAM Normalization function:
1. First select F6 MORE 1/2 to go to the second menu level.
2. Press F1 NORMALIZE. to activate the QAM Normalization function. Use the softkey
menus:
F1 ADD NEW NORM. TABLE to save a new normalization table.
F2 SELECT/UNSELECT CURRENT ITEM to select normalization table.
F3 RENAME CURRENT ITEM to rename selected normalization table.
F4 DELETE CURRENT ITEM to delete the selected normalization table.
8-10
8.6
Chapter 8
QAM 16/64/256 Digital Measurements
QAM Impairment Analysis (QIA) Display
The QAM Impairment Analysis function displays the results of 14 measurements at once:
Figure 8-9: QAM Impairment Analysis (QIA) Screen
To activate the QIA display:
1.
From QAM analyzer mode, press F1 to select ANALYSIS.
2.
Press F5 SET QIA PARAMETERS. The AT2500HM has two separate tables for 64
QAM and 256 QAM. Impairment Analysis for 16 QAM is not available.
3.
Press F1 to select the appropriate table for the signal modulation type. Choose a value for
the Minor and Major limits of each parameter. The value you choose determines the limits
of the color bar graphs in QIA mode (red, yellow, green). The following parameters can be
set:
• Mod. error ratio (MER)
• Carrier offset
•
Estimated noise margin (ENM)
•
Symbol rate error
•
Error vector magnitude (EVM)
•
Carrier/Interference (C/I) ratio
•
I/Q gain differential
•
Compression
•
I/O phase differential
•
Frequency Response (P/V)
•
Phase noise
•
Echo margin
•
System noise ratio
•
Hum
Chapter 8
8-11
QAM 16/64/256 Digital Measurements
Figure 8-10: QIA Setup Menu
4.
Press F5 to save the setup and return to the QAM analyzer analysis screen.
5.
Press F3 to start the signal analysis.
9-1
Chapter 9
VeEX SERVICE AND
SUPPORT
VeEX is committed to excellent service worldwide. Our goal is to provide you with
professional assistance in the use of our software and services, wherever you are located.
Technical Support and Customer Service solutions vary by country. If you have questions
about the services described below, refer to section 9.2, Technical support on page 9-1.
VeEX also provides product training to regional VeEX representatives so that they can offer
some product support in your region in a prompt and personalized manner.
9.1
AT2500HM Maintenance
9.1.1
RF Connector Replacement
Since the RF input and output connectors may receive many insertions per day of coaxial cable,
the life of the connectors can be fairly short. The connectors are a 1 GHz rated, common type
“F” double female that can be easily replaced with the aid of a 7/16-inch wrench. No case
disassembly is required. Exact replacement F-connectors are available from VeEX.
Technical support
9.2
VeEX is located in the Eastern Time zone with regular office hours from 8:00 AM to
8:00 PM. A toll free number service covering all of North America is provided at no charge.
Key VeEX personnel can always be reached any time of the day through a toll free number or
electronic mail service over the Internet.
International customers should contact the nearest VeEX Representative, or the factory at:
North America Toll Free: 1-800- 297-9726
Outside of North America: 1-514-725-6652
Fax: 1-514-725-5637
E-mail address for Technical Support: catv@VeEXtelecom.com
website: www.VeEXtelecom.com
Returning Equipment to VeEX
9.3
VeEX manufactures equipment to very high standards. Products are warranted against defects
in materials and workmanship, as specified in our published product warranty. When properly
used and operated, your equipment will provide many years of service. Should it become
necessary to return the equipment to VeEX for in or out of warranty repairs or for calibration,
please see Customer’s Responsibility below for the steps to follow.
Note:
If products are repaired or altered by persons not authorized by VeEX, or not in
accordance with instructions furnished by VeEX or if the products have become
defective due to a result of misuse, improper repair, abnormal operating conditions, then
the labor and materials required to effect the changes will be billed at our standard repair
rates.
Customer’s Responsibility
1.
Contact VeEX and request a Return Material Authorization (RMA) number. Be sure to
have your model and serial number ready.
9-2
Chapter 9
Sunrise Service and Support
2.
After receiving the RMA number, return the equipment with an accurate description of the
symptoms and be sure to state the authorization number on your paperwork. The client is
responsible for all transportation charges to VeEX.
Original packaging is preferred. If unavailable, carefully package the equipment in
alternate packing material to ensure adequate protection during shipping.
VeEX’s Responsibility
1.
VeEX will acknowledge the receipt of the returned equipment and at that time bring any
discrepancies to your attention.
2.
VeEX will replace or repair, at its discretion, any component or sub-assembly it deems
necessary to return the unit to a proper condition.
3.
After the necessary repairs, VeEX will perform complete test and re-calibration of the
unit.
All precautions are taken by VeEX to ensure that every unit meets all electrical and
mechanical specifications prior to returning the equipment to the client.
Note:
VeEX is not responsible for failures caused by transportation to/from the customer’s
location, nor by rough handling by the customer after receipt causing further damage to
the product. VeEX is solely responsible for the defects stated above and in our
standard product warranty policy.
If you require information or assistance, contact VeEX at 1-800-297-9726 toll free from
anywhere in North America or by fax at 1-514-725-5637 or by e-mail to:
info@VeEXtelecom.com.
10-1
Chapter 10
SPECIFICATIONS
10.1
AT2500HM Specifications
Note:
10.1.1
10.1.2
All specifications apply over the standard 0°C to + 50°C operating temperature range,
after a minimum of 2½ hours of storage within the operating temperature range, if the
unit is not fully at ambient temperature. The AT2500HM meets all its specifications within
1 minute after it is turned on, providing that the AT2500HM is within the one-year
calibration cycle. The AT2500HM’s autocal feature assures its accuracy by periodically
self-testing and triggering a non-obstructive calibration, as required.
Frequency
Tuning Range
0 – 1500 MHz
Calibrated Frequency Range
5 – 1500 MHz
Frequency Reference Ageing
± 1 PPM / yr
Frequency Reference Temperature Stability
± 1 PPM (0° to 50°C)
Frequency Counter Accuracy
± 1 PPM ± 1 count
Frequency Counter Resolution
10 Hz
Single Sideband Phase Noise at 10 kHz
Offset
-85 dBc/Hz typical;
-83 dBc/Hz minimum
Spans
Max Span
1500 MHz
Variable Spans
0.1 to 1500 MHz, user programmable
Zero Span
10.1.3
Sweep Time
Max Span and > 1000 MHz
30 ms
Other spans ≤1000 MHz
20 ms to 5 s
In 2, 5, 10, 20 sequence
10.1.4
Reduced Spans (≤500 MHz, ≤100 MHz,
≤50 MHz)
10, 4, 2 ms
Sweep Trigger
Sweep modes: Free run, Pwr Line, TV
frame (Spectrum Analyzer sweep
modes)
Zero Span Horizontal Time
0.05 ms to 500 ms, in 1, 2, 5, 10
sequence
Resolution Bandwidth
1 MHz
Selectivity 5.3 to 1, 60 dB/3 dB
300 kHz
Selectivity 3.1 to 1, 60 dB/3 dB
30 kHz
Selectivity 2 to 1, 60 dB/3 dB
10 kHz
Selectivity 2 to 1, 60 dB/3 dB
10-
10.1.5
Chapter 10
AT2500HM Specifications and Compliance
Video Bandwidth
10 KHz, 100 KHz, 1 MHz
10.1.6
6 dB /octave
Amplitude
Signal Level Range Note 1
Maximum Safe Input
-70 dBmV min.
68 dBmV
+70 dBmV max.
100V AC/DC
Level Accuracy Note 2
±0.75 dB max.
5–1500 MHz
Sensitivity
Note 3
-65 dBmV
Level Resolution
0.1 dB
Input Impedance
75 Ohms nominal
Input Return Loss, Attenuator ≥ 5 dB Note 4
20 dB typical
14 dB min.
16 dB typical
8 dB typical
10 dB min.
11 dB max.
Average Displayed Noise Floor
-62 dBFS
300 KHz RBW, avg2,
CF at100MHz.
Average Noise Floor Flatness
+2/- 0.5 dB max.
+3/- 0.5 dB max.
5 – 1000 MHz
5 – 1500 MHz
Spurious Free Dynamic Range
70 dB
Internally generated CTB
Better than 70 dB
79 channel loading at
Full Scale, Att<20dB
Pre-amp ON, Filter
AUTO ON
Internally generated CSO
Better than 70 dB
79 channel loading at
Full Scale, Att<20dB
Pre-amp ON, Filter
AUTO ON
Vertical Scale
10, 5, 2 dB / div
70 dB full scale
Reference Level Range
+70 / -10 dB
Attenuator
0–65 dB
Input Return Loss, Attenuator = 0 dB
Noise Figure, 5–1500 MHz
10.1.7
Field-replaceable
F-81 connector
Note 4
5 dB steps
Internal Band Select Filters
Choice of user-selectable filters Note 5, in manual or automatic mode.
In manual mode, the user can choose 7 high pass filters, 7 low pass filters, or 21 bandpass filter
combinations (1 high pass and 1 low pass filter used together).
In automatic mode, the AT2500HM selects the bandpass filter according to the center
frequency and span.
Chapter 10
10-3
AT2500HM Specifications and Compliance
Band Select Filters
10.1.8
Filter Types
5th Order, 30 dB/octave
Ultimate Rejection
> 50 dB
Insertion Loss (automatically included in
attenuator setting)
~ 5 dB Note 6, amplitude calibrated
High Pass Cutoff Frequencies
35, 78, 164, 270, 360, 450, 540 MHz
Low Pass Cutoff Frequencies
Bandpass Cutoff Frequencies:
35 to
45, 88, 174, 280, 370, 460, 550 MHz
88, 174, 280, 370, 460, 550 MHz
Bandpass Cutoff Frequencies:
78 to
174, 280, 370, 460, 550 MHz
Bandpass Cutoff Frequencies:
164 to
280, 370, 460, 550 MHz
Bandpass Cutoff Frequencies:
270 to
370, 460, 550 MHz
Bandpass Cutoff Frequencies:
360 to
460, 550 MHz
Bandpass Cutoff Frequencies:
450 to
550 MHz
Miscellaneous
Parameter
10.1.9
Size
Value
482 x 133 x 355 (mm)
(19"W x 5.25"H x 14"D)
Remark
Weight
7 kg ( 15.5 pounds)
Temperature, Operating
5 to +40°C
Temperature, Storage
-20°C to +55°C
Pollution Degree
II
Installation Category
II
Altitude
Up to 2000 m
Humidity
80% up to 31°C
Shock and Vibration
3 g maximum
Power Supply Class
II, Tolerance: 16 VDC, 4.06 A
PSU2065
Current Consumption
2.2 A max
2 A typical at 12 VDC
3 RU (Rack Units) High
Decreasing linearly to
50% at 40°C
Mechanical and Environmental Specifications
General
Temperature Readout Range
-15°C to 100°C ± 1.5°C
Display type
External VGA monitor
Power
Internal Battery Charger
Charger Protection
Note 7
Automatic Fast / Slow / Floating
Reverse polarity, Over/Under voltage 12/18 V
Power Supply PSU2065
100V/250V, 50/60 Hz, 16 VDC, 4.06 A
Certification
UL1950 UL136791
CSA950 LR36665
CE TUV / IEC 1950
10-4
Chapter 10
AT2500HM Specifications and Compliance
Battery
10.1.10
Battery Type
Rechargeable lead acid, 12 Volt 2 Ah.
Charge Time
Approx. 30 minutes
Operating Time on Backup
Battery
Approx. 15 minutes
CATV Measurement Specifications
Channel Selection
Frequency, Channel Video, Channel Audio
Channel Plans
Custom plans, NTSC (EIA, HRC, IRC), PAL (B/G, I, D) or
other. Maximum of 350 signals (analog, digital, FM,
upstream, test, etc.). PC-based and internal complete
channel plan editor
Tuning Range
0 MHz to 1.5 GHz
Calibrated Operating Range
5 MHz to 1.5 GHz
TV Channel Amplitude Range
-40 dBmV to +65 dBmV ± 0.75 dB for S/N > 30 dB
TV Visual Frequency
Accuracy
Carrier Frequency, ± 1 PPM
Resolution
10 Hz
Visual/Aural Delta Frequency
Range
1–10 MHz
Accuracy
± 200 Hz
Resolution
10 Hz
Visual/Aural Delta Amplitude
± 0.75 dB for S/N > 30 dB
FM Deviation
Range
± 150 kHz, de-emphasis 75 µsec
Accuracy
± 2 kHz, 1–75 kHz, ± 5 kHz to 150 kHz
HUM/Low Frequency Disturbances
Modes
CW or Video (In-Service)
Range
1– 10 %
Accuracy
± 0.5 % from 1 to 5%, ± 1% from 5 to 10%
Modulation Depth
AM Range
40 to 95%
Resolution
0.1%
Accuracy
± 1.5% (CCN > 40 dB)
Signal type
Use VITS line with white reference
In-Channel Frequency Response
Range
± 10 dB
Resolution
0.1 dB
Accuracy
± 0.25 dB
Signal Type
Use VITS line with full amplitude CATV multiburst
signal, ghost canceling reference signal or video
sweep.
Chapter 10
10-5
AT2500HM Specifications and Compliance
Carrier-to-Composite Noise Ratio
Optimum Signal Range
+5 dBmV to +10 dBmV, noise measured with 0 dB
attenuation
Maximum CCN
60 dB with ± 1 dB accuracy, 65 dB with ± 3 dB
accuracy
Resolution
0.1 dB
CSO/CTB
10.1.11
10.1.12
Note 8
Note 8
Optimum Signal Range
0 dBmV to +10 dBmV, beat measured with 0-5 dB
attenuation
Maximum
CSO/CTB 70 dB with ± 1.5 dB accuracy, 77 dB with
± 4 dB accuracy, Resolution 0.1 dB
TDM Measurement Option
Frequency Span
Zero Span
Horizontal Time
50 µsec to 500 ms (1, 2, 5 settings)
Resolution Bandwidth
1 MHz, 300 kHz, 30 kHz, 10 kHz
Video Bandwidth
1 MHz, 100 kHz, 10 kHz
Frequency Span
Zero Span
Bandwidth Correction Range
10 kHz to 9.99 MHz
Pulse Level Accuracy
± 0.75 dB in 5 µsec
Trigger Modes
Free run, Continuous, Single
Trigger Level Range
70dB dynamic range at any attenuator setting
-70 dBmV to +65 dBmV total range Note 9
Trigger Delay Range
0 to 100 ms, in 1 µsec steps
Trigger Holdoff Range
50 µsec to 100 ms, in 1 µsec steps
Digital Measurement QAM 16/64/256 Specifications
Modulation
Modulation Type
16/64/256 QAM ITU-T J.83 Annex A, B & C (DVS,
DVB, DOCSIS, EuroDOCSIS)
Interleave Capability
In Annex B, up to 128 x 4; In Annex A/C, 12 x 17
Constellation Display
16, 64 and 256 QAM, Full constellation with zoom
capability
Adaptive Equalizer Display
Number of Taps: 8 feed-forward; 24 feedback
Adaptive Equalizer Control
On, Freeze, Variable, Off
Scale
+10 to -80 dBc
Frequency response over signal +5 to -5 dB
bandwidth
Group delay over signal
bandwidth
-1000 to 1000 nsec
10-6
Chapter 10
AT2500HM Specifications and Compliance
Digital Carrier Average Power Measurement
Amplitude Range
-30 to +65 dBmV
Resolution
0.1 dB
Absolute Accuracy
± 1.5 dB
Measurement Range
200 kHz to 1500 MHz
Modulation Error Ratio (MER)
Range
22 to 40 dB
Accuracy
± 0.5, 22 to 30 dB; ±1, 30 to 38 dB; ±1.7dB, 38 to
40 dB
Error Vector Magnitude (EVM)
Range
0.65% to 4.1%
1 Second Period Bit Error Rate (BER), Before and After R-S Decoding
Range
0 to 1.0 x 10-4
User-selectable Time Rest
Period
1 to 60 minutes
Estimated Average Bit Error Rate (BER), Before and After R-S Decoding
Range
0 to 1.0 x 10-4
User-selectable Time Period
1 to 60 minutes, 7 days with WinQAM remote control
software
Resolution
1 second
Estimated Noise Margin
Range
1 to 12 dB
Accuracy
± 0.5, 22 to 30 dB; ±1, 30 to 38 dB; ±1.7dB, 38 to
40 dB
Data Logging
User-selectable Time Period
1 to 60 minutes, 7 days with WinQAM remote control
software
MER, Pre and Post BER, Errored Seconds, Severely
Errored Seconds, Frame Loss, System Unavailability
Time
Resolution
1 second
Symbol Rate
Range
1 to 7 MS/s.
Chapter 10
10-7
AT2500HM Specifications and Compliance
10.1.13
Analog Video Measurements
Function
Available Features
Waveform Monitor
1, 2 or 3 user selectable lines plus x10 zoom of one line
Vertical scale of 20, 10 or 5 IRE /div., reference offset
Horizontal and vertical markers, Average 1 to 50
Luminance, chrominance and noise weighting filters
Vectorscope
One selectable line, vector gain adjustment and phase rotation
Measurements
• Differential gain and phase
• Luminance to chrominance delay and gain
• Depth of modulation and modulation linearity
• Signal-to-noise unweighted and weighted
• FFC limits pass/fail indicator
Measurement setup: the type of video test signal determines the available measurements;
markers allow positioning the sampling location.
10.2
Video Measurements
Differential Phase
± 1.5° typical
± 3° maximum
Differential Gain
± 1% typical
± 2% maximum
Luminance to Chrominance Delay
± 20 nsec typical
± 40 nsec maximum
Luminance to Chrominance Gain
± 1.5% typical
± 3% maximum
Depth of Modulation
± 1% typical
± 2% maximum
Modulation Linearity
± 1 IRE typical
± 2 IRE maximum
Signal to Noise (unweighted)
± 2 dB typical
± 4 dB maximum
Signal to Noise (weighted)
± 2 dB typical
± 4 dB maximum
Notes
Note 1
Note 2
Note 3
Note 4
Note 5
Note 6
Note 7
Note 8
Note 9
Signal level range is defined as the maximum detectable range using attenuator,
reference level, resolution bandwidth and averaging.
Response flatness and level accuracy are measured with CW or non-scrambled
analog video modulation.
Sensitivity is measured with attenuator and reference level at 0 dB and CF=100
MHz, Span=10 MHz, RBW= 300 kHz, VBW= 10 kHz, average 2. It is defined as a
1.5 dB hump above noise floor.
Return loss specifications, when the attenuator is <15 dB, are not valid for internal
band select filter operation.
Band select filters internal to the spectrum analyzer/receiver are covered by US
Patent 6,495,998.
The 5 dB insertion loss of the band select filters is calibrated so measured levels are
still within specifications, but the 0 dB attenuator position is not accessible.
Power supply voltage range: 16 VDC +/-10%, under-voltage internal protection
<12 VDC, over-voltage internal protection >18 VDC.
CCN, CTB and CSO are characterized with 78 channels, modulated with 50% duty
cycle at 15 kHz, using internal band select filter.
Trigger Level Range will be –65 dBmV to +65 dBmV if band select filters are
turned on.
10-8
Chapter 10
AT2500HM Specifications and Compliance
Figure 10-1: CCN Accuracy
Figure 10-2: CSO/CTB Accuracy
Chapter 10
10-9
AT2500HM Specifications and Compliance
10.3
Compliance documentation
Electrical compliance documentation is pending. Documentation will be updated when available.
11-1
Chapter 11
GLOSSARY
11.1
Abbreviations
ASCII
ASI
American Standard Code for Information Interchange
Asynchronous Serial Interface
BAS
Bi-directional Alignment System
BER
Bit Error Rate
BPS
Bits Per Second
CCN
Carrier to Composite Noise
CSO
Composite Second Order
CTB
Composite Triple Beat
CW
Carrier Wave or Continuous Wave
DFE
Decision Feedback Equalizer
DHCP
DNS
ENM
ES
EVM
Dynamic Host Configuration Protocol
Domain Name Server
Estimated Noise Margin
Errored Second
Error Vector Magnitude
FCC
Federal Communications Commission
FEC
Forward Error Correction
FFE
FIFO
Feed Forward Equalizer
First In First Out
FLS
Frame Loss Second
FPS
Frames Per Second
ITU
International Telecommunication Union
MER
MPEG
PoP
Modulation Error Ratio
Motion Pictures Expert Group
Proof of Performance
PPM
Parts Per Million
QAM
Quadrature Amplitude Modulation
RBW
Resolution Bandwidth
RMS
Root-Mean-Square
SES
SRTB
SWT
TCP/IP
TDM
UL
USB
Severely Errored Second
VeEX Telecom Broadband
Sweep Time
Transmission Communication Protocol/Internet Protocol
Time Domain
Underwriters’ Laboratory
Universal Serial Bus
VBW
Video Bandwidth
VITS
Vertical Interval Test Signal
11-2
11.2
Chapter 11
Glossary
Terms
Autocal
Routine that automatically adjusts the AT2500HM’s measurement
functions to a set of computer-generated traceable calibration
standards, compensated for the current ambient temperature.
Autotest
Function to automatically measure frequencies and levels for all
tagged channels and frequencies in the active channel plan.
Baud Rate
See Speed.
Beat-Near-Noise The beat correction factor obtained when the internal noise of the
Correction spectrum analyzer is compared to the measured system noise (in dB).
Bit Error Rate Measurement for a digital signal that indicates the ratio of data
(BER) received in error compared to the total number of bits received in a
given period, e.g. 1 second. Pre-FEC BER measurements show the
ratio of errors after digital decoding (i.e. after Trellis decoding, derandomization and de-interleave) but before and after Reed-Solomon
error correction. Post-FEC BER measurements show the ratio over a
second of errors that cannot be corrected and which are therefore
transmitted.
Carrier-To- The relationship of a carrier’s power level to the system noise floor,
Composite Noise expressed in dB. This measurement is calculated from the power in a
Ratio (CCN) sinusoidal signal, whose peak is equal to the peak of a visual carrier,
divided by the system noise power in a 4 MHz bandwidth.
Channel Plan
List of channels (line-up) for a particular headend or location.
Channel Plan List of channel plan files in the AT2500HM memory.
Directory
Channel Plan List of channel plans within a selected file. A channel plan contains
File individual channel line-ups.
Composite Distortion measurement that shows the products generated by the
Second Order direct addition or subtraction of fundamental visual carrier frequencies.
(CSO) CSO products normally fall at ±750 kHz or ±1.25 MHz from the
visual carriers.
Composite Triple Distortion measurement that shows the ratio, expressed in dB, of the
Beat (CTB) peak level of the RF signal to the peak of the average level of the
cluster of distortion components centered around the carrier frequency.
CTB is another type of third order intermodulation unique to CATV,
since the majority of channels are spaced exactly 6 MHz (or another
fixed offset) from each other.
Digital Channel Sum of power level acquisitions across the desired measurement
Power bandwidth.
DOCSIS
Domain
Data Over Cable Service Interface Specification is a standard
developed to provide a common set of rules enabling interoperability
between transmitting equipment and receiving equipment through a
transmission channel.
A name that identifies one or more IP addresses.
Error Vector Measurement of modulation quality of the transmitted signal before
Magnitude the forward error correction stage. It is calculated as follows:
(EVM) Error Vector Magnitude = (maximum symbol magnitude / rms error
magnitude) X 100%
Errored Second Indicates that one packet has an uncorrected error within a
(ES) measurement second (post-FEC).
Chapter 11
Glossary
11-3
Estimated Noise Indication of the headroom of the system, expressed in dB. ENM is
Margin (ENM) calculated from the MER, taking into account QAM modulation type,
symbol rate and bandwidth.
Forward Error Method for controlling errors in a one-way system by sending extra
Correction information along with the data, which can be used by the receiver to
(FEC) check and correct the data using a predetermined algorithm.
Frame Loss Indicates that within a measurement second, the frame lock has been
Second (FLS) lost at least once.
Free Run Mode Mode of operation where the AT2500HM continually scans and
retraces the signal. The scan-retrace cycle repeats indefinitely until a
different mode is selected.
Gateway
Hub
Alternate term for router. Computer network device that connects
autonomous systems by intercepting and routing data from one
network to another. Gateways use the subnet number of data and
determine which IP addresses to process based on a subnet mask.
Computer network device that accepts data from multiple points and
then forwards the data using a switch.
Hum Modulation
The total peak-to-peak power line hum and low frequency AM
modulation at all frequencies from DC to 1 kHz expressed as a
percentage relative to the peak level of the reference carrier.
Mapping
In QAM modulation, the allocation of the symbol bits to each of the
location of the constellation.
Modulation The ratio of average total signal power in the ideal constellation to the
Error Ratio average error power in the constellation as received by the
(MER) AT2500HM, expressed in dB. It is calculated as follows:
10 X log (average symbol power/average error power) dB
Noise-Near-Noise Changes in attenuation automatically applied to CCN measurements
Correction for the measurement band, based on the calibrated noise floor of the
AT2500HM.
Preset
Function that returns the AT2500HM instrument settings to their
factory-default values.
Pwr Line Mode
Mode of operation where the AT2500HM scan-retrace cycle repeats at
the power line frequency, which is 60 Hz or 50 Hz depending on how
the channel is defined in the channel plan.
Reference Level
Measurement level in dBmV shown at the top of the AT2500HM’s
graticule display. The reference level is user-definable with a given
range.
Reference Offset
Adjustment factor in dB applied to the signal level read by the
AT2500HM in order to take into account external gain or loss due to
amplifiers, pads, filters, cables and so on, thus modifying the level
displayed on the AT2500HM.
Remote Mode of operation where the AT2500HM is controlled by a VeEX
Spectrum Mode software application running on a PC.
Resolution Difference in frequency between two data points, based on the number
(Frequency) of data points (display resolution) and on the span.
Resolution The width of the AT2500HM’s adjustable IF filter. Optimal RBW is
Bandwidth related to sweep time, span and video bandwidth.
(RBW)
Router
Device that forwards packets between networks. The decision to
forward or not is based on the network layer and routing tables.
11-4
Chapter 11
Glossary
Sensitivity
Ability to measure low-level signals. Input attenuator and resolution
bandwidth settings affect the sensitivity by changing the signal-tonoise ratio. Attenuator settings affect the level of signal passing
through the input of the instrument, whereas the resolution bandwidth
affects the level of internal noise without affecting the signal.
Severely Errored Indicates the total number of measurement seconds where the ratio of
Seconds (SES) errored packets to transmitted packets is higher than a user settable
threshold (from 1E-4 to 1E-2).
Signal-to-Noise The ratio of the amplitude of the desired signal to the amplitude of
Ratio (S/N) noise signals. S/N is usually expressed in dB as 20 X log (amplitude
ratio) or 10 X log (power ratio), in peak values for impulse noise and
RMS values for random noise.
Softkey
Onscreen menu options that correspond to one of the six unlabeled
buttons to the right of the AT2500HM’s display.
Speed
Rate at which the data is sent through the AT2500HM’s serial port,
measured in bits per seconds (bps) or in baud (state changes per
second). Baud and bps are synonymous only for two-level modulation
with no framing or stop bits. The AT2500HM’s maximum speed is
115000 bps.
Subnet
A segment of an IP network. In an IP address, a portion of the address
is used to identify the subnet. A subnet mask is used by routers to
forward data to the network segment, based on its own routing tables.
A typical subnet mask is 255.255.255.0, which indicates that the router
should allow or deny access based on the first three parts of the IP
address.
Sweep Time
The time that the AT2500HM takes to read all the data points on the
AT2500HM display. Sweep time is related to span, resolution
bandwidth and video bandwidth.
Switch
Tag
Test Point
In return path monitoring applications, a device that selects an input.
In the AT2500HM, a checkmark indicating that a channel, record or
test option has been selected.
Connection on a device used for making signal measurements.
TV Frame Mode
Mode of operation where the AT2500HM scan’s starting time repeats
at the video frame rate, which is 29.97 Hz or 25 Hz depending on how
the channel is defined in the channel plan.
Unav
Unavailability Time. A period of at least 10 consecutive severely
errored seconds. The unavailability status is cleared when the
AT2500HM detects 10 consecutive non-SES seconds. The 10 nonSES seconds are not included in the unavailability time.
Video Bandwidth The adjustable video averaging function on the AT2500HM. Optimal
(VBW) VBW is related to sweep time, RBW and span.
Zero Span Mode
AT2500HM mode for viewing signals in the time domain instead of
the frequency domain typically used for TV signal analysis.
Chapter 12
Index
Chapter 12
12-1
INDEX
10Base-T ............................................................... 4-7
256 QAM............................................................... 8-1
64 QAM................................................................. 8-1
A65000909 option ................................................. 1-4
A99026010 option .......................................... 1-3, 1-4
A99026020 option ................................................. 1-4
A99026050 option ................................................. 1-4
Abbreviations ...................................................... 11-1
Accuracy
CCN ....................................................... 10-5, 10-8
CSO ....................................................... 10-5, 10-8
CTB ....................................................... 10-5, 10-8
digital carrier power........................................ 10-6
ENM ............................................................... 10-6
frequency counter ........................................... 10-1
level ................................................................ 10-2
visual frequency.............................................. 10-4
Adaptive equalizer................................................. 8-7
Add channel plan ........................................ 4-20, 4-21
AM detector........................................................... 5-3
Amplifier compression .......................................... 8-5
Amplitude .............................................................. 5-7
Amplitude shortcut ......................................... 3-5, 5-1
Amplitude specifications ............................ 10-2, 10-4
Analog channel setup .......................................... 4-22
Analysis (QAM) .................................................. 8-10
Arrow keys ............................................................ 3-6
ASCII .................................................................. 11-1
ASI ...................................................................... 11-1
ASI output ...................................................... 3-3, 3-4
AT2500HM maintenance ...................................... 9-1
AT2CATVPAK option.......................................... 1-3
AT2TDM option.................................................... 1-3
AT2VIDOUT option ............................................. 1-3
ATCATVPAK option............................................ 6-1
Attenuator .............................................................. 5-7
ATWx0 option....................................................... 1-4
ATWx2 option....................................................... 1-4
Audio carrier (TV channel mode) ......................... 6-2
Audio offset ......................................................... 4-22
Autocalibration .............................1-1, 3-1, 5-13, 11-2
Autocouple ............................................................ 5-4
Autotest ........................................................ 6-4, 11-2
AUX. VIDEO output...................................... 3-3, 3-4
Average 1 .............................................................. 5-7
Bandwidth compensation .................................... 10-5
BAS ..................................................................... 11-1
Baseband
AT2VIDOUT.................................................... 1-3
functions ........................................................... 1-3
Battery
charge time ..................................................... 10-4
operating time ................................................. 10-4
type ................................................................. 10-4
warranty period ................................................. 1-5
Battery charger ...................................... 1-3, 2-1, 10-3
Baud rate ........................................... 4-10, 4-25, 11-2
Beat-near-noise.................................................... 11-2
Beat-near-noise correction..................................... 6-9
BER ........................11-1, 11-2, See also Bit error rate
BER threshold ....................................................... 8-2
Bit error rate ................................................. 8-1, 11-2
BPS...................................................................... 11-1
Broadband switches............................................. 4-25
Cable
Ethernet............................................................. 4-8
serial ................................................................. 1-4
Cable multiburst .................................................. 6-10
Calibration ............................................................. 1-4
Carrier
offset ............................................................... 8-11
sweep ................................................................ 6-4
Carrier/Interference (C/I) ratio ............................ 8-11
Carrier-to-noise ................................................... 11-2
CATV
AT2CATVPAK ................................................ 1-3
functions ........................................................... 1-3
CATV distortions .................................................. 6-5
Caution symbol...................................................... 1-2
CCN............................................................ 11-1, 11-2
measurement values.......................................... 6-8
measurements ................................................... 6-7
CCN ratio specifications............................. 10-5, 10-8
Channel
audio offset ..................................................... 4-22
autotest............................................................ 4-22
name ............................................................... 4-22
number ............................................................ 4-22
type ................................................................. 4-22
Channel plan........................................................ 11-2
Channel plan setup .............................................. 4-20
Channel plans
download ........................................................ 4-12
specifications .................................................. 10-4
Channel setup
analog ............................................................. 4-22
digital .............................................................. 4-24
other ................................................................ 4-24
Charge time ......................................................... 10-4
Charger .................................................................. 2-1
Coefficients ........................................................... 8-8
Coherent distortion ................................................ 8-5
12-2
Chapter 12
Index
Colors
download schemes .......................................... 4-12
user schemes ................................................... 4-19
COM port.................................................3-3, 3-4, 4-7
Company identification........................................ 4-17
Compare trace ........................................................ 4-4
Composite second order....................................... 11-2
Composite triple beat ........................................... 11-2
Compression ........................................................ 8-11
Configuration ........................................... See Settings
Connect
printer................................................................ 4-6
Connection device ................................................. 4-8
Connector replacement .......................................... 9-1
Constellation display ...................................... 8-1, 8-5
Consumption........................................................ 10-3
Container ............................................................... 2-1
Contents (box) ....................................................... 2-1
Context related help screens .................................. 3-1
Continuous mode ................................................... 7-4
Continuous symbol display.................................... 8-6
Copy channel plan ............................................... 4-21
Copyright .................................................................. 2
CSO ............................................................ 11-1, 11-2
CSO measurements................................................ 6-7
specifications.......................................... 10-5, 10-8
values ................................................................ 6-9
CTB ............................................................ 11-1, 11-2
CTB measurements................................................ 6-7
application note ................................................. 6-7
specifications.......................................... 10-5, 10-8
values ................................................................ 6-9
Custom screen colors ........................................... 4-19
Customer service ................................................... 9-1
CW interference..................................................... 8-5
Cyclic display ........................................................ 8-6
Damage .................................................................. 2-1
Data communications ............................................ 4-7
Data logging ........................................................ 10-6
Data points ............................................................. 5-7
Data transfer ........................................................ 4-12
Date (display) ........................................................ 3-6
Date format .......................................................... 4-18
Decision boundaries............................................... 8-5
Default channel plan ................................... 4-20, 4-21
Default instrument settings ............................. 2-3, 4-1
Definitions ........................................................... 11-2
Degradation (QAM)............................................... 8-4
Delay after trigger .................................................. 7-3
Delete
channel ............................................................ 4-21
channel plan .................................................... 4-20
Deleting records..................................................... 4-5
Depth of modulation ............................................ 6-11
Deviation kHz scale ............................................... 5-3
DFE (decision feedback equalizer) ............... 8-8, 11-1
DFE equalizer length ............................................. 8-3
DHCP .................................................................. 11-1
DHCP server .......................................................... 4-8
DHCP Usage.......................................................... 4-8
Digital channel power ................................... 6-1, 11-2
Digital channel setup ........................................... 4-24
Discrete Frequency Interference ............................ 6-8
Display
specifications................................................... 10-3
trace................................................................... 4-2
units................................................................. 4-18
Display Switch Information ................................. 4-17
Distortion
amplifier compression....................................... 8-5
bandpass............................................................ 8-8
coherent............................................................. 8-5
CW interference ................................................ 8-5
measurements.................................................... 6-7
QAM ................................................................. 8-4
DNS ..................................................................... 11-1
DOCSIS ............................................................... 11-2
Domain ................................................................ 11-2
Domain name......................................................... 4-8
Duplicate channel plan......................................... 4-21
Dynamic range..................................................... 10-2
Earth .................................................... See Grounding
Echo margin......................................................... 8-11
Edit channel plan ........................................ 4-20, 4-21
Electrical connection ............................................. 2-1
E-mail .................................................................... 9-1
ENM .................8-4, See also Estimated noise margin
ENTER key............................................................ 3-6
Environment .......................................................... 2-1
Epson printer.......................................................... 4-5
Equalizer
coefficients ........................................................ 8-8
display ........................................................ 8-7, 8-8
setup .................................................................. 8-3
Erasing records ...................................................... 4-5
Error vector magnitude (EVM)................... 8-11, 11-2
ES (errored second) ...................................... 8-7, 11-2
ESC shourcut ......................................................... 3-6
Estimated noise margin (ENM) ...........8-4, 8-11, 11-3
Estimated vector magnitude (EVM) ...................... 8-4
Ethernet cable ........................................................ 4-8
Ethernet connection ............................................... 3-6
Ethernet option....................................................... 1-3
Ethernet port ............................................3-3, 3-4, 4-7
EVM ..........8-4, See also Estimated vector magnitude
Exit remote mode................................................... 4-9
Factory defaults ..................................................... 2-3
Fax ......................................................................... 9-2
FCC reporting .................................. 1-1, 1-3, 4-1, 4-7
F-connectors .......................................................... 9-1
Features........................................................... 1-1, 1-3
FFE (feed-forward equalizer) ................................ 8-8
FFE equalizer length .............................................. 8-3
FIFO .................................................................... 11-1
Chapter 12
Index
File manager .......................................................... 4-2
File transfer.......................................................... 4-12
Filter
activate.............................................................. 5-2
application note................................................. 5-3
bandpass ........................................................... 5-2
equalization....................................................... 8-8
frequencies...................................................... 10-2
high pass ........................................................... 5-2
low pass ............................................................ 5-2
mode ............................................................... 4-18
specifications .................................................. 10-2
Filter options.......................................................... 1-3
Firmware ............................................................. 4-12
Flow control delay ............................................... 4-10
FLS (frame loss second) ............................... 8-7, 11-3
FM detector ........................................................... 5-3
FMdeviation specifications ................................. 10-4
Forward error correction............................... 8-1, 11-3
Frame rate.............................................................. 4-9
Frame zoom ........................................................... 8-6
Free run mode...................................... 5-13, 7-4, 11-3
Freeze trace............................................................ 4-4
Frequency counter ............................................... 5-13
Frequency references ...............................................3-5
Frequency response ............................................. 8-11
equalizer ........................................................... 8-8
Frequency shortcut ......................................... 3-5, 5-1
Frequency tuning ................................................... 5-2
Front panel............................................................. 3-2
Gated test method .................................................. 6-7
Gateway............................................................... 11-3
Gateway address .................................................... 4-9
Ghost canceling carrier ........................................ 6-10
Glossary............................................................... 11-2
Grace period .......................................................... 1-5
Graph
equalizer ........................................................... 8-8
frequency response ........................................... 8-8
Grid display ........................................................... 8-6
Grounding....................................................... 1-1, 1-2
Group delay ........................................................... 8-8
Help screens .......................................................... 3-1
Help shortcut ......................................................... 3-5
HM ........................................................... See Models
HMQ......................................................... See Models
Holdoff ......................................................... 7-3, 10-5
Horizontal markers ................................................ 5-9
Horizontal time ...................................................... 7-2
Host name.............................................................. 4-8
HP LaserJet printer ................................................ 4-5
Hum modulation ......................................... 8-11, 11-3
measurement .............................................. 6-5, 6-6
specifications .................................................. 10-4
Humidity.............................................................. 10-3
Icons ...................................................................... 3-7
In-channel frequency response ............................ 10-4
12-3
In-channel method ................................................. 6-7
Initial verification .................................................. 2-2
Input level............................................................ 10-2
Inspection ....................................................... 2-1, 2-2
Installation
category .......................................................... 10-3
location ............................................................. 2-1
Instrument settings
default ............................................................... 2-3
recall ................................................... See Settings
Invalid key beep .................................................. 4-18
IP address setup ..................................................... 4-7
IP mask .................................................................. 4-8
Keyboard ........................................................ 3-3, 3-4
Keyboard shortcuts ................................................ 3-5
LAN connection .................................................... 4-7
LaserJet printer ...................................................... 4-5
Levels and frequencies .......................................... 6-4
Live display ........................................................... 4-9
Location (installation) ........................................... 2-1
Log scale ............................................................... 5-3
Main menu...................................................... 3-5, 3-6
Maintenance .......................................................... 9-1
Mapping .............................................................. 11-3
Marker shortcut .............................................. 3-5, 5-1
Markers ...................................................................3-5
Mass .................................................................... 10-3
Master Group Start .............................................. 4-25
Max span ............................................................... 5-3
Measurements
recall ................................................................. 4-2
store .................................................................. 4-1
Memory ................................................................. 4-5
Memory clear shortcut........................................... 3-6
Memory shortcut ................................................... 3-6
Menu shortcut........................................................ 3-5
Menus (spectrum analyzer) ................................... 5-1
MER ...................................................................... 8-4
MER threshold ...................................................... 8-2
Models ................................................................... 1-2
Modulation
analog channel ................................................ 4-22
digital .............................................................. 4-24
Modulation depth ................................................ 10-4
Modulation error ratio (MER) ......8-1, 8-4, 8-11, 11-3
Modulation scale ................................................... 5-3
Modulation type (digital)..................................... 10-5
Modulation type (QAM)........................................ 8-2
Modules ................................................................. 3-7
Moisture ................................................................ 2-1
Monitor port ................................................... 3-3, 3-4
MPEG.................................................................. 11-1
MPEG output........................................... 3-3, 3-4, 8-3
Multi-carrier mode................................................. 6-3
Multiple Trace Display.......................................... 5-7
Network connection............................................... 4-8
Network port................................................... 3-3, 3-4
12-4
Chapter 12
Index
NO AVERAGE ..................................................... 5-7
Noise
phase ................................................................. 8-5
system noise ratio............................................ 8-11
thermal .............................................................. 8-5
Noise figure ......................................................... 10-2
Noise floor ........................................................... 10-2
Noise marker .......................................................... 3-5
Noise-near-noise correction .......................... 6-9, 11-3
Normal operation ................................................... 2-4
Offset
carrier .............................................................. 8-11
reference............................................................ 5-7
Operating time ..................................................... 10-4
Options
WinCom II ................................................. 1-3, 1-4
WinQAM .......................................................... 1-4
WinRemote ....................................................... 1-4
Other channel setup ............................................. 4-24
Output MPEG ........................................................ 8-3
Packing materials ................................................... 2-1
Parallel port............................................................ 3-3
Parameters setup .................................................. 4-17
Patent ................................................................... 10-7
Peak hold ........................................................ 5-7, 5-9
Phase noise ..........................................8-5, 8-11, 10-1
Pilot
setup ................................................................ 4-24
Polarity type (QAM) .............................................. 8-2
PoP.........................................................1-1, 4-1, 11-1
Port
Ethernet ...................................................... 3-3, 3-4
monitor ....................................................... 3-3, 3-4
parallel .............................................................. 3-3
printer................................................................ 3-3
RS-232C............................................................ 3-6
USB................................................................... 3-4
video........................................................... 3-3, 3-4
Post-FEC BER ....................................................... 8-3
Power connection................................................... 2-1
Power cord ...................................................... 1-1, 1-2
Power jack ............................................................. 1-3
Power Off Beep ................................................... 4-18
Power Off Timer.................................................. 4-17
Power supply ......................................................... 1-3
class................................................................. 10-3
input ........................................................... 3-3, 3-4
Power switch............................................2-1, 3-3, 3-4
PPM ..................................................................... 11-1
Precision frequency counter................................. 5-13
Pre-FEC BER ........................................................ 8-3
Preferences........................................................... 4-16
Preprogrammed settings ........................................ 4-2
Preset ................................................................... 11-3
Preset shortcut........................................................ 3-5
Previous Mode shortcut ......................................... 3-5
Print records........................................................... 4-7
Print reports ........................................................... 6-5
Print screen ............................................................ 4-6
Print shortcut.......................................................... 3-6
Printer .................................................................... 3-4
compatible models ............................................ 3-6
driver .................................................3-6, 4-5, 4-18
port .................................................................... 3-3
type ................................................................. 4-18
Proof-of-Performance ..................................... 1-1, 4-1
Protection
charger ............................................................ 10-3
shipping container ............................................. 2-1
warranty ..................................................... 1-4, 1-5
PSU2065 option..................................................... 1-3
PSU2065 specifications ....................................... 10-3
Pure thermal noise ................................................. 8-5
Pwr line mode ............................................. 5-13, 11-3
QAM
modulation ........................................................ 8-2
normalization .................................................. 8-10
normalization download.................................. 4-12
polarity type ...................................................... 8-2
Standard type .................................................... 8-2
statistical mode.................................................. 8-2
symbol rate........................................................ 8-2
QAM analyzer ....................................................... 8-1
setup .................................................................. 8-1
specifications................................................... 10-5
statistics............................................................. 8-7
QIA parameters.................................................... 8-11
Rating (power supply) ........................................... 1-3
RBW ...................................................................... 5-4
realWORX ...................................................... 1-1, 1-4
Rear panel ....................................................... 3-3, 3-4
Recall records ........................................................ 4-2
Recall shortcut ....................................................... 3-5
Recalling records ................................................... 4-1
Receiving ............................................................... 2-1
Records
download......................................................... 4-12
erase .................................................................. 4-5
recall.................................................................. 4-2
store................................................................... 4-1
Reference level ............................................. 5-7, 11-3
Reference offset ............................................ 5-7, 11-3
Remote mode .......................................4-9, 4-10, 11-3
Remote shortcut ..................................................... 3-6
Remote switches .................................................. 4-25
Report headers ....................................................... 4-7
Resolution
frequency ............................................... 5-13, 11-3
frequency counter............................................ 10-1
level................................................................. 10-2
Resolution bandwidth ................................... 5-4, 11-3
filter................................................................... 6-1
specifications................................................... 10-1
time domain ...................................................... 7-2
Chapter 12
Index
values ................................................................ 5-4
Return Material Authorization number ................. 9-1
Returning equipment ............................................. 9-1
RF input ................................................... 1-2, 3-3, 3-4
connector replacement ...................................... 9-1
levels ............................................................... 10-2
RMA...................................................................... 9-1
RMS .................................................................... 11-1
Router .................................................................. 11-3
RS-232 port .................................................... 3-3, 3-4
RWORX-AMM ..................................................... 1-4
RWORX-DMM ..................................................... 1-4
RWORX-RMM ..................................................... 1-4
RWORX-XMP ...................................................... 1-4
Safety..................................................................... 1-1
Sales support.......................................................... 1-5
Sample length ........................................................ 8-6
Screen colors ....................................................... 4-19
Sensitivity ................................................... 10-7, 11-4
Serial cable ............................................................ 1-4
Serial communications .......................................... 4-7
Serial connection ................................................. 4-10
Serial port ............................................................ 4-25
Server ID ...................................................... 4-9, 4-10
Server live display ................................................. 4-9
SES (severely errored second)............................... 8-7
Settings
default ............................................................... 2-3
download ........................................................ 4-12
erase .................................................................. 4-5
recall ................................................................. 4-3
store .................................................................. 4-2
Setup........................................4-16, See also Settings
channel plan .................................................... 4-20
equalizer (QAM)............................................... 8-3
QAM analyzer .................................................. 8-1
Severely errored seconds (SES) .......................... 11-4
Shipping ................................................................ 2-1
Shortcuts ................................................................ 3-5
Signal bandwidth correction .................................. 7-1
Signal-to-noise ratio (S/N) .................................. 11-4
Single mode ........................................................... 7-4
Size ...................................................................... 10-3
Slope...................................................................... 7-3
Softkeys ........................................................ 3-5, 11-4
Software options ............................................. 1-3, 1-4
Span related functions ........................................... 5-3
Span shortcut .................................................. 3-5, 5-1
Span specifications .............................................. 10-1
Specifications ...................................................... 10-1
Spectrum analyzer functions ................................. 5-1
Speed .......................................................... 11-2, 11-4
SRTB System Type ............................................. 4-18
Standard functions ................................................. 3-7
Standard type (QAM) ............................................ 8-2
Statistical graph ..................................................... 8-7
Statistical mode ..................................................... 8-2
12-5
Statistics
QAM................................................................. 8-7
WinQAM ........................................................ 4-15
Store records.......................................................... 4-1
Store settings ......................................................... 4-2
Store shortcut......................................................... 3-5
Subnet.................................................................. 11-4
Superimposing ....................................................... 4-4
Sweep method ..................................................... 5-13
Sweep time ................................................... 5-4, 11-4
specifications .................................................. 10-1
values ................................................................ 5-5
Switch
COM port........................................................ 4-25
download configuration .................................. 4-12
setup................................................................ 4-25
type ................................................................. 4-25
Symbol display ...................................................... 8-6
continuous......................................................... 8-6
cyclic................................................................. 8-6
sample length .................................................... 8-6
time filter .......................................................... 8-6
Symbol rate................................................... 8-2, 8-11
Symbols (explanation)........................................... 1-2
System ID .............................................................. 4-9
System type .................................................. 4-9, 4-10
Tag....................................................................... 11-4
channels ............................................................ 6-4
records .............................................................. 4-5
TCP/IP Network .................................................... 4-8
TDM .................................................................... 11-1
Technical support ........................................... 1-5, 9-1
Telephone .............................................................. 9-1
Temperature
calibration ......................................................... 3-1
operating ......................................................... 10-3
readout range .................................................. 10-3
storage............................................................. 10-3
Terms................................................................... 11-2
Test point ............................................................. 11-4
Thermal noise ........................................................ 8-5
Third order intermodulation ................................ 11-2
Tilt ......................................................................... 8-8
Tilt marker ............................................................. 5-9
Time .................................................................... 4-18
Time (display) ....................................................... 3-6
Time domain
AT2TDM .......................................................... 1-3
functions .................................................... 1-3, 7-1
specifications .................................................. 10-5
Time filter.............................................................. 8-6
Total number of RPTP......................................... 4-25
Trace
display............................................................... 4-2
download records............................................ 4-12
freeze ................................................................ 4-4
recall ................................................................. 4-2
12-6
Chapter 12
Index
superimpose ...................................................... 4-4
symbol display .................................................. 8-6
Trace shortcut ................................................. 3-5, 5-1
Trademark................................................................. 2
Transportation........................................................ 2-1
Trigger functions ................................................... 7-2
Trigger level ................................................. 7-3, 10-5
Tuning range ............................................... 10-1, 10-4
TV Channel mode.................................................. 6-2
TV Frame mode .......................................... 5-13, 11-4
Unav ............................................................. 8-7, 11-4
Uncalibrated measurement .................................... 2-4
Unpacking.............................................................. 2-1
Upgrade firmware ................................................ 4-12
USB port ......................................................... 3-4, 3-6
User identification ............................................... 4-18
User interface......................................................... 3-2
User preferences .................................................. 4-16
User preferences (download) ............................... 4-12
VBW ...................................................................... 5-4
Vectorscope
specifications................................................... 10-7
Vertical markers..................................................... 5-9
time domain ...................................................... 7-4
zoom.................................................................. 7-4
Vertical scale ................................................ 5-7, 10-2
VGA output .................................................... 3-3, 3-4
Vibration .............................................................. 10-3
Video bandwidth.................................................... 5-4
specifications................................................... 10-2
time domain ...................................................... 7-2
values ................................................................ 5-5
Video bandwidth (VBW)..................................... 11-4
Video carrier .......................................................... 6-2
Video measurements............................................ 10-7
Video NTSC on Boot........................................... 4-17
Video NTSC Output ............................................ 4-17
Video NTSC Timer.............................................. 4-17
Video port ....................................................... 3-3, 3-4
VITS ........................................................... 6-11, 11-1
Warning symbol..................................................... 1-2
Warranty
battery ............................................................... 1-5
extended option ................................................. 1-4
standard ............................................................. 1-5
void ................................................................... 1-2
Waveform monitor
specifications................................................... 10-7
Website .................................................................. 9-1
Wide band sweep ................................................. 6-10
WinCom II ........................................................... 4-12
WinQAM ............................................................. 4-15
WinRemote .......................................................... 4-14
Zero span mode.............................. 1-1, 5-3, 5-4, 11-4
Zoom
constellation mode ............................................ 8-5
time domain ...................................................... 7-4
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