Prism Sound DSA-1 User manual

Operation Manual
Issue 2.00 1st March 1996
Prism Media Products Limited
William James House
Cowley Road
Cambridge
CB4 4WX
U.K.
Telephone [phone]
Fax [phone]
Email [e-mail]
© Prism Media Products Limited, 1993, 1996

Prism Operation Manual Issue 2.00
Page i
Document history and revision level
This revision history of the DSA-1 operation manual is :
Issue 1.10 , 01/06/93 Ian Dennis Original release
Issue 2.00 , 01/03/96 Ian Dennis Updated for V2.0 firmware
A file named `READ.ME' may be included with the software; it includes information
relevant to this manual. The purpose of the `READ.ME' file is to provide the most up-to-
date information about program development; as such the file may post-date the latest
manual issue or revision.

Prism Operation Manual Issue 2.00
Page ii
CONTENTS
1. Introduction ................................................ 1.1
1.1. Summary of capabilities ................................. 1.2
1.2. Systemoptions ........................................ 1.5
1.3. Using this manual ...................................... 1.6
2. GettingstartedwiththeDSA-1 ................................. 2.1
2.1. Equipmentoverview .................................... 2.1
2.2. TurningontheDSA-1 ................................... 2.2
2.3. Connecting a digital audio input ........................... 2.3
2.4. Somebasictests....................................... 2.4
2.5. Running an automatic Test Sequence ...................... 2.5
2.6. Try the Signal Generator ................................. 2.6
3. DSA-1 I/O connectors ........................................ 3.1
3.1. DI (Digital-audio Input) connectors ......................... 3.2
3.2. DO (Digital-audio Output) connectors ....................... 3.2
3.3. REF SYNC input connectors .............................. 3.3
3.4. Headphone socket ..................................... 3.3
3.5. Test-out connectors .................................... 3.4
3.6. RS-232 serial port ...................................... 3.5
3.7. DC IN connector ....................................... 3.6
4. Indicator panels ............................................. 4.1
4.1. CARRIER panel indications .............................. 4.1
4.1.1. FAILindicator.................................... 4.1
4.1.2. ERRORindicator ................................. 4.1
4.1.3. N.FAILindicator .................................. 4.2
4.1.4. BLOCK/PHASE error indicator ....................... 4.2
4.1.5. A'LOGindicator .................................. 4.2
4.1.6. fs frequency display ............................... 4.2
4.1.7. fsaccuracydisplay................................ 4.3
4.2. DATA panel indications .................................. 4.4
4.2.1. Sub-framedisplay ................................ 4.4
4.2.2. Channel Status display ............................. 4.5
5. DSA-1controlsreference ..................................... 5.1
5.1. Menu keys ............................................ 5.1
5.2. Audiomonitorcontrols .................................. 5.1
5.3. I/O selection controls ................................... 5.2
5.3.1. DIkey.......................................... 5.2
5.3.2. TERMkey....................................... 5.2
5.3.3. CHANkey....................................... 5.3
5.3.4. DOkey ......................................... 5.3
5.3.5. SYNCO/Pkey ................................... 5.4

Prism Operation Manual Issue 2.00
Page iii
6. DSA-1 menus reference ...................................... 6.1
6.1. Carrier tests (menu 1.) .................................. 6.4
6.1.1. fs Freq (menu 1.1.) ................................ 6.4
6.1.2. fs Jitter (menu 1.2.) ............................... 6.5
6.1.3. Data Jitter (menu 1.3.) ............................. 6.6
6.1.4. Amplitude (menu 1.4.) ............................. 6.8
6.1.5. Eye Closure (menu 1.5.) ............................ 6.8
6.1.6. Errors (menu 1.6.) ................................ 6.9
6.1.7. Phase v Ref (menu 1.7.) ........................... 6.10
6.1.8. CM Ampl (menu 1.8.) ............................. 6.10
6.1.9. LoBand Ampl (menu 1.9.) .......................... 6.10
6.1.10. Log Carrier (menu 1.10.) ..................... 6.11
6.2. Data tests (menu 2.) ................................... 6.12
6.2.1. Audio Meter (menu 2.1.) ........................... 6.13
6.2.2. Active Bits (menu 2.2.) ............................ 6.14
6.2.3. C-S Fields (menu 2.3.) ............................ 6.15
6.2.4. C-S Bytes (menu 2.4.) ............................ 6.16
6.2.5. C-S Idents (menu 2.5.) ............................ 6.16
6.2.6. C-S Timecode (menu 2.6.) ......................... 6.17
6.2.7. Log Data (menu 2.7.) ............................. 6.18
6.3. Test Sequences (menu 3.) .............................. 6.19
6.3.1. Run (menu 3.1.) ................................. 6.20
6.3.2. Select (menu 3.2.) ............................... 6.21
6.3.3. Log Sequence (menu 3.3.) ......................... 6.22
6.4. Generator (menu 4.) ................................... 6.23
6.4.1. Sync Source (menu 4.1.) .......................... 6.27
6.4.2. Edit Modes (menu 4.2.) ........................... 6.28
6.4.3. Audio Function (menu 4.3.) ........................ 6.29
6.4.4. Audio Parameters (menu 4.4.) ...................... 6.30
6.4.5. Channel Status (menu 4.5.) ........................ 6.31
6.4.6. C-S Capture (menu 4.6.) .......................... 6.33
6.4.7. Valid Bit (menu 4.7.) .............................. 6.34
6.4.8. Jitter Generator (menu 4.8.) ........................ 6.35
6.4.9. Log Generator (menu 4.9.) ......................... 6.36
6.5. Channel Check (menu 5.) ............................... 6.38
6.5.1. Run to Log (menu 5.1.) ............................ 6.39
6.5.2. Setup (menu 5.2.) ................................ 6.41
6.6. Watchdog (menu 6.) ................................... 6.43
6.6.1. Run to Log (menu 6.1.) ............................ 6.44
6.6.2. Setup (menu 6.2.) ................................ 6.46
6.7. Microscope (menu 7.) .................................. 6.47
6.8. Results Log (menu 8.) .................................. 6.49
6.8.1. Start Block (menu 8.1.) ............................ 6.51
6.8.2. Print Log (menu 8.2.) ............................. 6.51
6.8.3. Clear Log (menu 8.3.) ............................ 6.52
6.8.4. Log Viewer (menu 8.4.) ........................... 6.52

Prism Operation Manual Issue 2.00
Page iv
6.8.5. Block Manager (menu 8.5.) ........................ 6.53
6.8.6. Form Feed (menu 8.6.) ............................ 6.53
6.9. System Setup (menu 9.) ................................ 6.54
6.9.1. Settings (menu 9.1.) .............................. 6.54
6.9.2. Save Setup (menu 9.2.) ........................... 6.58
6.9.3. Defaults (menu 9.3.) .............................. 6.59
6.9.4. Ref Learn (menu 9.4.) ............................ 6.60
6.9.5. Battery Charge (menu 9.5.) ........................ 6.61
6.9.6. Host Mode (menu 9.6.) ............................ 6.62
7. UsingtheDSA-1withahostPC ................................ 7.1
7.1. Installing the DSA-1 Host Support software .................. 7.1
7.1.1. MS-Windows software installation .................... 7.1
7.1.2. MS-DOSsoftwareinstallation ....................... 7.2
7.2. Results Log Uploader/Editor software ....................... 7.3
7.2.1. Introduction ...................................... 7.3
7.2.2. Using the Results Log Uploader/Editor ................ 7.3
7.3. Test Sequence Compiler/Downloader software ............... 7.6
7.3.1. Introduction ...................................... 7.6
7.3.2. Elements of a Test Sequence ....................... 7.6
7.3.3. Test Sequence Instruction reference .................. 7.8
7.3.4. Using the Test Sequence Compiler/Downloader ........ 7.15
7.4. Automated and Remote operation ........................ 7.21
7.4.1. SerialSlavemode ............................... 7.21
7.4.2. MacroProcessorsoftware ......................... 7.21
7.5. Downloading firmware updates ........................... 7.32
8. DSA-1 test and measurement techniques ......................... 8.1
8.1. System trouble-shooting ................................. 8.1
8.2. Evaluating equipment outputs ............................. 8.2
8.2.1. General source trouble-shooting ..................... 8.3
8.2.2. Sourcecarriertests ............................... 8.4
8.2.3. Sourcedatatests ................................. 8.5
8.3. Evaluating equipment inputs .............................. 8.6
8.3.1. General receiver trouble-shooting .................... 8.6
8.3.2. Receivercarriertests .............................. 8.7
8.3.3. Receiverdatatests................................ 8.7
8.4. Evaluating'in-line'performance ........................... 8.8
8.4.1. 'In-line'carriertests ............................... 8.8
8.4.2. 'In-line'datatests ................................. 8.9
8.5. Evaluating AES3 cabling and interconnects ................. 8.11
8.6. Evaluating A/D and D/A converters ........................ 8.12
8.7. Analogue audio pathfinding ............................. 8.16
9. Specification ............................................... 9.1
Appendix A - Introduction to the AES3 interface ......................... A.1

Prism Operation Manual Issue 2.00
Page v
Appendix B - DSA-1 Serial Data Protocol .............................. B.1
Appendix C - System Test Sequence Listings ........................... C.1
Appendix D - References ........................................... D.1

Prism Operation Manual Issue 2.00
Page 1.1
1. Introduction
The DSA-1 is a hand-held instrument for measuring connectivity parameters of stereo
digital audio signals in one of the formats described in AES3-1992 and IEC958
(commonly referred to as AES/EBU or SPDIF). The recently-proposed AES3-ID coaxial
format is also supported. Testing of 110 6 balanced, 75 6 coaxial or TOSLINK optical
media is possible. The DSA-1 can also generate a wide range of test signals, and can
edit signals 'in-line'. The unit may be powered from its internal rechargeable battery
or from an external DC power supply.
The parameters measured and signals generated by the DSA-1 are intended to provide
a means of assessing `connectivity'; i.e. the likelihood of trouble-free interconnection.
There are many factors which have implications for connectivity, for example the
sampling-rate of the sending equipment or the number of bits present in the audio data
word. The level and correctness of the Channel Status implementation is also
important if proper connectivity is to be achieved.
The consequences of failure to meet connectivity requirements can range from
complete failure, as when a source operates at a sample-rate not supported by a
receiver, or the most subtle effects which result from truncation of the audio word, as
when a 20-bit source is connected to a 16-bit device without provision for truncation
processing such as re-dithering or noise-shaping.
Among the most frustrating of connectivity problems are those which lead to intermittent
operation, where infrequent clicks or drop-outs mar audio quality. These may occur at
random, or may be related to program content. Such problems are most often the
result of inadequate operating margin in some electrical or timing parameter of the
interface, due to either equipment or cabling problems.
The DSA-1 is a tool designed to measure connectivity parameters with great accuracy
and simplicity. Its automatic Test Sequences can detect subtle abnormalities in
interface conditions without the need for detailed analysis by the operator.
Although the DSA-1 includes a number of basic audio-data generation and analysis
functions, it does not provide distortion measurements or other sophisticated audio
analyses; the Prism Sound Dscope is a high-performance digital audio test system
(including generator and analyzer) which focuses on signal content, rather than
connectivity.

Prism Operation Manual Issue 2.00
Page 1.2
1.1. Summary of capabilities
The following section briefly summarises the capabilities of the DSA-1 version 2.0
firmware for the benefit of new operators. For operators experienced in the use of the
DSA-1 version 1.0 firmware, new features are marked with an asterisk.
Carrier Analysis:
LED panel: Summarises major carrier faults (including biphase or parity errors,
poor eye-width, incorrect Channel Status block length and
analogue content) and displays sampling rate and grade.
Sampling rate: Measures sampling rate (fs);
Measures sampling rate accuracy in ppm;
fs measurements may be calibrated to house reference;
Jitter: Measures fs Jitter (from source);
Measures Data Jitter (from cable);
Measures eye-pattern degradation;
De-jittered output available;
Selectable jitter corner-frequency;
Amplitude: Measures differential amplitude;
Measures common-mode component;
Measures audio-band component;
Phase: Measures carrier phase with respect to reference;
Data Analysis:
LED panel: Summarises audio, Validity, User and Channel Status bits;
Audio amplitude: * Bargraph meter with numerical readout in dBFS or hex;
Bit activity: Displays which bits are active in the audio word;
Channel Status: Displays binary data and functional description;

Prism Operation Manual Issue 2.00
Page 1.3
Test Sequences: Allow the operator to test incoming signal to professional or
consumer standards at the press of a button, without detailed
knowledge of the interface specifications.
* Operator or in-house standards authority may compose custom
Test Sequences on a host PC which are then loaded into the
DSA-1.
* Generator: Sine, square, triangle, ramp, pulse, Jtest, or noise functions;
Variable amplitude, frequency and audio word-length;
Fully programmable Channel Status, field by field;
Independent A and B channel settings;
Channel Status pattern can be 'cloned';
Programmable Valid bit;
Jitter generation;
Synchronises to AES3/11, wordclock or local reference;
Editing mode: In-line editing of Channel Status, field by field;
In-line editing of Valid bit;
In-line superimposing of generator audio signal;
In-line jitter modulation;
* Channel Check: Checks cables, tape machines, data links etc. by comparing every
incoming audio bit within the selected word-length with the
pseudo-random data generated at the output. Errors are logged
against time and can be printed. Check is delay-independent, and
source and checker can be remote from each other.
* Watchdog: Operator can identify CARRIER and DATA panel parameters to be
'watched', e.g. sampling rate accuracy, biphase errors, Validity bit,
Channel Status CRC errors. Variations of the identified
parameters are logged against time and can be printed. Distinct
alarm strings for each watched parameter can be transmitted from
the RS-232 port if required.
* Microscope: Digital gain up to 90dB can be applied to incoming audio, with a
selected input word-length imposed, prior to the monitoring DAC
and DO outputs. This allows evaluation of dithering and noise-
shaping schemes.

Prism Operation Manual Issue 2.00
Page 1.4
* Results Log: Measurement results, settings etc. can be printed immediately or
held in non-volatile memory for later printing or uploading to a host
PC.
Monitoring DAC: Feeds headphones or integral loudspeaker;
Test Inputs: XLR (AES3), coaxial (AES3-ID, SPDIF), optical (CP340);
Copper inputs have switchable termination for in-line use;
Test Outputs: XLR (AES3), coaxial (AES3-ID, SPDIF);
Ref Sync Inputs: XLR (AES3/11), coaxial (AES3/11, wordclock);
'Scope Outputs: Isolated, unbalanced, x10, 75 6 signal plus programmable sync;