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9581 SST R5
Return Path Analyzer
Operation Manual
Trilithic Company Profile
Trilithic is a privately held manufacturer founded in 1986 as an engineering and assembly company that built and designed customer-directed products for telecommunications, military, and industrial customers. From its modest beginnings as a two-man engineering team, Trilithic grew over the years and broadened its offerings of RF and microwave components by adding broadband solutions to its product line. This was accomplished with the acquisition of components manufacturer Cir-Q-Tel and instruments manufacturer Texscan.
Today, Trilithic is an industry leader providing telecommunications solutions for major broadband, RF, and microwave markets around the world. As an ISO 9000:2001 certified company with over 40 years of collective expertise in engineering and custom assembly, Trilithic is dedicated to providing quality products, services, and communications solutions that exceed customer expectations.
Trilithic is comprised of five major divisions:
•Broadband Instruments and Systems
Offers test, analysis, and quality management solutions for the major cable television systems worldwide.
•Telecom Solutions
Offers affordable, easy-to-use instruments for testing and measurement of Telecom networks.
•RF Microwave Components
Provides components and custom subsystems for companies specializing in cellular, military, and other wireless applications.
•Emergency Alert Systems
Leading supplier of government-mandated emergency alert systems used by broadcast TV, cable TV, IPTV, DBS, and radio stations.
•XFTP
Offers a specialty line of field technical products for cable operators and technicians, as well as a line of products for installing electronics in the home of the future.
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Table of Contents |
|
1. General Information .............................................................................................................. |
5 |
Helpful Website ..................................................................................................................... |
5 |
Where to Get Technical Support ............................................................................................. |
5 |
How this Manual is Organized ................................................................................................ |
6 |
Conventions Used in this Manual ........................................................................................... |
7 |
Precautions ........................................................................................................................... |
8 |
2. Introduction........................................................................................................................... |
9 |
System Overview ................................................................................................................... |
9 |
Application ............................................................................................................................ |
9 |
Balancing the Return Path .............................................................................................. |
10 |
Measuring Ingress and Noise ......................................................................................... |
10 |
Return Path Maintenance ..................................................................................................... |
11 |
9581 SST Headend Analyzer ............................................................................................... |
12 |
Included Equipment ............................................................................................................. |
12 |
Optional Equipment ............................................................................................................. |
12 |
A Guided Tour of Your 9581 SST R5 .................................................................................... |
13 |
Front View ...................................................................................................................... |
13 |
Back View ...................................................................................................................... |
14 |
3. Optimizing the Return Path ............................................................................................... |
15 |
Introduction .......................................................................................................................... |
15 |
Return Path Perfomance Parameters................................................................................... |
15 |
Signal-to-Noise Ratio ..................................................................................................... |
16 |
Signal-to-Ingress Ratio ................................................................................................... |
16 |
A Balanced System ........................................................................................................ |
16 |
4. Installation ........................................................................................................................... |
19 |
Overview ............................................................................................................................. |
19 |
Pre-Installation Considerations ............................................................................................ |
19 |
Reverse Test Carriers ..................................................................................................... |
19 |
Forward Data Carrier ..................................................................................................... |
20 |
Installing the 9581 SST R5 ................................................................................................... |
21 |
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Display Screen Overview ..................................................................................................... |
23 |
Instrument Information ..................................................................................................... |
23 |
Instrument Time, Date, & Internal Temperature ........................................................... |
23 |
Firmware & Software Version Numbers .................................................................... |
23 |
Setup Menu Navigation .................................................................................................. |
24 |
Viewing the Network Settings .................................................................................... |
24 |
Viewing the RX Frequency Settings .......................................................................... |
25 |
Viewing the RX Level Settings .................................................................................. |
25 |
Viewing the Link Frequency Settings ......................................................................... |
26 |
Viewing the Remote Detection Type Settings ............................................................ |
26 |
Adjusting the Speaker Settings ................................................................................. |
27 |
Adjusting the Display Screen Contrast Settings ......................................................... |
28 |
5. Operation............................................................................................................................. |
29 |
Overview ............................................................................................................................. |
29 |
Setting up the 9581 SST R5 ................................................................................................ |
29 |
Remote Operation ............................................................................................................... |
30 |
Return Path Alignment.......................................................................................................... |
30 |
Adjusting the Fiber Link ....................................................................................................... |
31 |
Adjusting Amplifiers ............................................................................................................. |
32 |
Ingress ................................................................................................................................. |
34 |
Extending the Measurement Range ..................................................................................... |
36 |
Reconfigure the 9581 SST R5 for Greater Range ........................................................... |
36 |
Increase Sensitivity and Range ....................................................................................... |
36 |
Effect of the Offset on the 860 DSP and 860 DSPi ......................................................... |
36 |
6. Appendix ............................................................................................................................. |
37 |
Specifications ...................................................................................................................... |
37 |
Warranty Information ............................................................................................................ |
38 |
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Chapter 1
General Information
Helpful Website
The following website contains general information which may be of interest to you:
http://www.trilithic.com
Trilithic’s website contains product specifications and information, tips, release information, marketing information, Frequently Asked Questions (FAQs), bulletins and other technical information. You can also check this website for product updates.
Where to Get Technical Support
Trilithic technical support is available Monday through Friday from 8:00 AM to 5:00 PM EST. Callers in North America can dial 317-895-3600 or 800-344-2412 (toll free). International callers should dial 317-895-3600 or fax questions to 317-895-3613. You can also email technical support at techsupport@trilithic.com.
For quicker support response when calling or sending e-mail, please provide the following information:
•Your name and your company name.
•The technical point of contact (name, phone number, e-mail).
•Product name, model number, and serial number.
•A detailed description of the problem you are having, including any error or information messages.
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How this Manual is Organized
This manual is divided into the following chapters:
•Chapter 1, “General Information” provides Trilithic contact information and describes how this operation manual is structured.
•Chapter 2, “Introduction” explains what the 9581 SST R5 does and provides an overview of the physical features of the device.
•Chapter 3, “Optimizing the Return Path” provides an overview of how to provide a reliable return path in order to optimize the system’s performance.
•Chapter 4, “Installation” provides installation instructions for the 9581 SST R5 and explains the use of the front display screen.
•Chapter 5, “Operation” provides instructions on how to use the 9581 SST R5 to balance the return path in order to optimize the system’s performance.
•Chapter 6, “Appendix” provides detailed technical specifications and warranty information.
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Conventions Used in this Manual
This manual has several standard conventions for presenting information.
•Connections, menus, menu options, and user-entered text and commands appear in bold.
•Section names, web and e-mail addresses appear in italics.
A WARNING alerts you to any condition that could cause personal injury.
A CAUTION alerts you to any condition that could cause a mechanical failure or potential loss of data.
A NOTE is information that will be of assistance to you related to the current step or procedure.
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Precautions
A strong electromagnetic field may affect the accuracy of the 9581 SST measurements.
Exposure of data cables to a field with high-voltage and fast transient signals may cause measurement errors in the 9581 SST.
A shielded CAT-5 cable is recommended for Ethernet connection.
Do not use the 9581 SST in any manner not recommended by the manufacturer.
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Chapter 2
Introduction
This chapter:
•Describes the purpose of the 9581 SST R5
•Lists the features of the 9581 SST R5
System Overview
The 9581 SST R5 Return Path Maintenance System is a single test system that enables management of all aspects of return path upkeep; including both ingress control and system balancing. At the core of the system is the 9581 SST R5 Return Path Analyzer, a 4.125 to 85.5 MHz digitizing spectrum analyzer which is installed at the headend of the cable system.
The 9581 SST R5 monitors all signals arriving at the headend, including reverse signal “traffic”, noise, ingress and test carriers from the 860 DSP or 860 DSPi field analyzer(s).
A single 9581 SST R5 can monitor up to sixteen separate headend test points simultaneously, allowing analysis of the condition of each test point. The 9581 SST R5 analyzes test signals and the return spectra separately and packages measurement results into a data stream that it transmits to the 860 DSP or 860 DSPi.
Each 860 DSP or 860 DSPi are addressed individually (A - F) which allows six field analyzers to be in operation at any one time. Each field analyzer transmits up to eight test carriers at usersettable frequencies. The 9581 SST R5 measures these test carriers to compute the gain and tilt of the return path. The 860 DSP and 860 DSPi can store up to 24 sweep displays which can be reviewed at a later time or uploaded to a PC.
During system testing, the 9581 SST R5 sorts out the test carrier measurements for each field analyzer and tags the data with the individual addresses (A – F) so that each field analyzer displays the appropriate information. When the field analyzer receives its data, it displays the response of the return path as either a line graph or as numeric values for gain and tilt. Ingress and noise data are presented as a spectrum analyzer display. For more information, refer to the 860 DSP and 860 DSPi Operation Manual.
Application
The 9581 SST Return Path Maintenance System can be used to:
•Balance the return path
•Measure the return path’s ingress and noise
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Balancing the Return Path
In the basic test architecture, test signals are injected upstream by the 860 DSP or 860 DSPi field analyzer. The 9581 SST R5 measures these signals automatically at the headend. The measurement data is transmitted back to the field analyzer for display.
To balance the return path of the system, several alignment objectives must be considered. The fiber return path link must be set to the system’s design specifications. Additionally, each line amplifier must be set so that it will compensate for the gain and tilt of the cable and passives to the next amplifier.
The 860 DSP and 860 DSPi have two types of displays which will accommodate amplifier adjustment differences:
•Eight-carrier line graph for amplifiers that require screwdriver adjustments
•Calculated gain and tilt values for amplifiers that use pads and equalizers
Measuring Ingress and Noise
In the basic test architecture, the spectrum analyzer of the 9581 SST R5 return path analyzer measures the incoming ingress and noise. It then transmits this measurement data to the 860 DSP or 860 DSPi field analyzers. The field analyzers display the ingress data as a spectrum pattern.
While analyzing the return path, it must be determined if the return frequencies carrying the “traffic” have an adequate signal-to-noise ratio. To calculate the signal-to-noise ratio, the effective ingress power must be calculated first. For narrow band ingress, such as CB or shortwave, measure the ingress power directly. For broadband ingress, such as interference from machinery, treat the ingress as noise and correct for video or data bandwidth. In the formulas below, measured power (MP) equals the reading from the 9581 SST R5 and IP equals the effective ingress power.
•Compute the effective noise in a 4 MHz video bandwidth; take the reading from the 9581 SST R5 and add 10.3 dB. IP = MP + 10.3 dB
•Compute the effective noise for data bandwidth, take the reading from the 9581 SST R5 and add 10 times the log (data BW divided by .375 MHz). IP = MP + 10 x log (data BW/.375 MHz)
•Maintain good picture quality, video signals require narrow band ingress to be between -40 and +60 dBc, depending on the offset from the video carrier and broadband ingress to be at least -40 dBc
Quadrature phase shift keying (QPSK) should have an effective ingress power of -20 dBc for either type of ingress for a bit error rate (BER) of approximately 1 x 10E-6.
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When the 9581 SST R5 is setup according to this manual, it reserves about 15 dB of amplitude measurement range to prevent the digitizer from being overloaded by powerful ingress transients. Experience has indicated that 15 dB is much more margin than is needed in all but the “dirtiest” systems. Up to 10 dB of the “guard band” can be reassigned to extend the measurement dynamic range of the 9581 SST R5. For more information, see Chapter 5: Operation, Extending the Measurement Range.
Return Path Maintenance
Cable television operators who maintain a two-way cable television distribution system knows that many factors can affect the performance of the system. Cumulative noise, signal ingress, incorrect gain, or bad flatness all conspire to harm the return path which can lead to loss of service and customer complaints.
The 9581 SST R5 is component of the next generation of the 9581 Return Path Maintenance System. The 9581 SST R5 monitors all of the troublesome parameters in a single, simple to use system. The 9581 SST R5 is a component of Trilithic’s Guardian II Return Alignment System which includes the 9581 SST R5 and 860 DSP or 860 DSPi with SSR or RSVP option. For additional information on each of the components in the Guardian II Return Alignment System, refer to the operation manual for each of the components.
The 9581 SST R5 differs from the 9581 SST R4 in several ways:
•The telemetry signal resides on a single transmitter which can be placed anywhere between 50 MHz and 1 GHz
•The bandwidth has been increased to 85.5 MHz
•There is no live display on the 9581 SST R5
The 9581 SST R5 Return Path Maintenance System is more than just a return alignment system. It also monitors the total performance of the return path by evaluating ingress and return noise. In any operation mode of the 9581 SST R5, transient events can be captured. In the Fast mode of the 9581 SST R5, the scan rate is tripled so smaller-duration transients can be captured. The Peak Hold mode enables the 9581 SST R5 to display the highest ingress points in Norm or Fast modes. This makes the 9581 SST R5 a powerful tool for capturing transient ingress. The Averaging feature is included and can be used to reduce the noise floor displayed when measuring CW or common path. The digitizer for the 9581 SST R5 handles 85.5 MHz in two bands.
The 9581 SST R5 is also equipped with TraffiControl. This feature enables the 9581 SST R5 to measure and plot the ingress spectra of bands occupied by return traffic. TraffiControl automatically filters all the “desired” signals from scanned return spectra so that only the ingress spectrum remains.
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9581 SST Headend Analyzer
The 9581 SST R5 headend analyzer is compact; occupying only 3.5" (2U) of rack space, and is easily set up and operated. A single 9581 SST R5 headend analyzer can support up to six 860 DSP or 860 DSPi field analyzers at a time with no loss of operating speed.
The 9581 SST analyzes sweep and ingress signals on sixteen separate test points individually. It sends the appropriate ingress spectrum and sweep data to each 860 DSP or 860 DSPi field analyzer to which it is connected.
Even when the 9581 SST R5 is not supporting the 860 DSP or 860 DSPi field analzyers, the 9581 SST R5 can function as a monitor for return path quality. Unattended locations can be monitored since the 9581 SST R5 can send ingress and sweep measurement data to a PC located in a central office (refer to the Viewer II Operation Manual for more information).
Included Equipment
The 9581 SST R5 Return Path Analyzer includes the following items:
•9581 SST R5 Return Path Analyzer
•Power Cable
•SST Configure Software on CD
•Operation Manual on CD
Optional Equipment
The following optional items are also available:
•Additional 9581 SST R5 headend analyzers
•860 DSP or DSPi field analyzer
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