Prism Sound DSA-1 Operation Manual
  1. Manuals
  2. Brands
  3. Prism Sound Manuals
  4. Controller
  5. DSA-1
  6. Operation manual

Prism Sound DSA-1 Operation Manual

Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
Operation Manual
Issue 2.00
1st March 1996
Prism Media Products Limited
William James House
Cowley Road
Cambridge
CB4 4WX
U.K.
Telephone +44-(0)1223 424988
Fax +44-(0)1223 425023
Email 100612.1135@compuserve.com
© Prism Media Products Limited, 1993, 1996

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the DSA-1 and is the answer not in the manual?

Questions and answers

Summary of Contents for Prism Sound DSA-1

  • Page 1 Operation Manual Issue 2.00 1st March 1996 Prism Media Products Limited William James House Cowley Road Cambridge CB4 4WX U.K. Telephone +44-(0)1223 424988 Fax +44-(0)1223 425023 Email 100612.1135@compuserve.com © Prism Media Products Limited, 1993, 1996...
  • Page 2 Prism Operation Manual Issue 2.00 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.

  • Page 3: Table Of Contents

    Turning on the DSA-1 ........2.2...
  • Page 4 DSA-1 menus reference ........
  • Page 5 Using the DSA-1 with a host PC ....... . 7.1...
  • Page 6 Operation Manual Issue 2.00 Appendix B - DSA-1 Serial Data Protocol ......B.1 Appendix C - System Test Sequence Listings .

  • Page 7: Introduction

    75 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.

  • Page 8: Summary Of Capabilities

    Operation Manual Issue 2.00 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.
  • Page 9 * 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;...
  • Page 10 Prism Operation Manual Issue 2.00 * Results Log: Measurement results, settings etc. can be printed immediately or held in non-volatile memory for later printing or uploading to a host 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;...

  • Page 11: System Options

    Updates to the DSA-1 firmware and Host Support software will be supplied on 3.5" diskette (contact Prism Media Products or your distributor for 5.25" media). Full details of how to use the DSA-1 Host Support software suite are given in section EMC STATEMENT The DSA-1 and its DC power supply conform to all applicable norms and standards for EMC prevailing in the countries in which it is sold.

  • Page 12: Using This Manual

    In this manual various conventions are used to identify keys, LEDS etc. on the DSA-1, and also on the host PC keyboard: A DSA-1 key name (or legend) is enclosed in square brackets thus [ ]; for example the ON key on the front panel of the DSA-1 would be referred to as [ON].

  • Page 13: Getting Started With The Dsa-1

    Operation Manual Issue 2.00 Getting started with the DSA-1 First, unpack your DSA-1 and check that you have all the items listed in the inventory in section 1.2. Check that the packaging and its contents are undamaged; if not contact your distributor or Prism Media Products Limited immediately.

  • Page 14: Turning On The Dsa-1

    `DC IN'. Connect the DC adapter to the mains, and plug its output into the unit's DC input connector. Switch on the DSA-1 by pressing the [ON] key. If all is well the 'CHARGE' indicator will light, followed shortly afterwards by the 'ON' indicator.

  • Page 15: Connecting A Digital Audio Input

    Having connected a suitable source, select the required input format (optical, co-axial or balanced) using the [DI] selector on the lower left of the DSA-1 control panel. The 'FAIL' LED on the CARRIER panel should extinguish and a sampling frequency and accuracy should be indicated.

  • Page 16: Some Basic Tests

    Operation Manual Issue 2.00 2.4. Some basic tests This section assumes that the settings of the DSA-1 are the factory defaults. If you have difficulty in reproducing the results below, please try again after instating the default settings via menu 9.3.

  • Page 17: Running An Automatic Test Sequence

    Operation Manual Issue 2.00 2.5. Running an automatic Test Sequence This section assumes that the settings of the DSA-1 are the factory defaults. If you have difficulty in reproducing the results below, please try again after instating the default settings via menu 9.3.

  • Page 18: Try The Signal Generator

    Generator and not the test input. Connect the XLR or coaxial test output ('DO') of the DSA-1 to a device capable of monitoring a digital audio input. You can use the DSA-1 for this by connecting one of the 'DO' outputs to the corresponding 'DI' input using an XLR or coaxial cable.
  • Page 19 Prism Operation Manual Issue 2.00 Pressing the [ENTER/NEXT] key twice moves the flashing arrow onto the generator amplitude parameter, initially set at -14dBFS. Operating the [<] or [>] keys now reduces or increases the amplitude setting. The generator mutes while the setting is being adjusted, then turns on at the new amplitude.

  • Page 20: I/O Connectors

    Prism Operation Manual Issue 2.00 DSA-1 I/O connectors Around the periphery of the membrane panel on the front and right-hand edges are several grey panels indicating the function of the connectors located immediately below. The following connectors are provided: •...

  • Page 21: Di (Digital-Audio Input) Connectors

    (such as jitter) are available. 3.2. DO (Digital-audio Output) connectors The DSA-1 can pass the signals from its BNC and XLR DI inputs directly to a pair of respective BNC and XLR outputs. This allows `in-line' measurements to be made.

  • Page 22: Ref Sync Input Connectors

    . Either can be driven with consumer or professional signals according to IEC 958/AES11. The BNC input can alternatively be driven with a TTL-level sampling-rate clock of 50% duty cycle (i.e. a 'Wordclock' or 'SDIF2 Wordsync'). The DSA-1 will automatically determine which connector and which format is in use whenever an external reference is required.

  • Page 23: Test-Out Connectors

    Prism Operation Manual Issue 2.00 3.5. Test-out connectors Two test outputs are provided to assist in the use of an oscilloscope for detailed examination of the signal-under-test. An unbalanced version of the signal at the selected DI connector (including the optical connector) is routed to the LINE test-out connector, thus providing a convenient means of viewing the received signal without unbalancing, misterminating or otherwise upsetting the line.

  • Page 24: Serial Port

    DSA-1 and the host PC. Such a cable is available as accessory DSA-1/NMC from Prism Media Products, or from your distributor.

  • Page 25: Dc In Connector

    2.1mm DC 'barrel' connector with the centre terminal positive. A supply voltage of 9V to 12V at a maximum current of 1A is required. In order to ensure safe and compliant operation, it is strongly advised that the DSA-1 only be used with the DC adapter supplied.

  • Page 26: Indicator Panels

    Prism Operation Manual Issue 2.00 Indicator panels In the central part of the DSA-1 front panel are two display panels which continuously display certain basic information about the signal-under-test. Apart from a few special cases, these panels are always active.

  • Page 27: N.fail Indicator

    This would render the signal irrecoverable to most receiving equipment. 4.1.4. BLOCK/PHASE error indicator This LED has a dual function: When the DSA-1's Signal Generator is turned off, the 'BLOCK' LED indicates that an incorrect number of samples has been counted in between successive `Z' preambles of the signal-under-test.

  • Page 28: Fs Accuracy Display

    The right-hand LED is designated 'WRT REF'; if this LED is lit, it indicates that the DSA-1 has been software-calibrated to an external Ref Sync as described in section 6.9.4. In this case, the accuracy measurement is made assuming that the external Ref Sync was absolute.

  • Page 29: Data Panel Indications

    Operation Manual Issue 2.00 4.2. DATA panel indications The 'DATA' panel is situated in the right-centre of the DSA-1 front panel. Its function is to provide a quick indication of the activity of the data bits in the sub-frame, i.e. the audio and the various ancillary bits.

  • Page 30: Channel Status Display

    Prism Operation Manual Issue 2.00 4.2.2. Channel Status display The Channel Status block is decoded into the various basic indications on the second and third rows of the DATA panel. The 'PRO' and 'CONS' LEDs indicate professional or consumer format Channel Status respectively.

  • Page 31: Controls Reference

    Prism Operation Manual Issue 2.00 DSA-1 controls reference The front panel of the DSA-1 has fourteen control keys which are highlighted in blue, plus the red [ON] key. The following section provides detailed descriptions of all the control key functions.

  • Page 32: I/O Selection Controls

    'in-line', via the ' ^' (loop-through) setting of the [DO] key. In this case, the DO connector carries the signal through the DSA-1 to be terminated at its destination. When the [DO] setting is 'RPT' or 'FNC', the termination setting is automatically over-ridden to 'LO-Z', but returns to the setting selected by the [TERM] key when loop-through mode is re-entered.

  • Page 33: Chan Key

    The DSA-1 is placed 'in-line' at the errant receiver, and can be toggled between loop-through and RPT modes to diagnose the failure.

  • Page 34: Sync O/P Key

    This allows the whole preamble and following data to be easily viewed on an oscilloscope. Note that when the DSA-1 Signal Generator is in use and synchronised to DI, the sync pulse is slightly advanced with respect to the DI data owing to internal timing constraints.

  • Page 35: Menus Reference

    Operation Manual Issue 2.00 DSA-1 menus reference The DSA-1 has an LCD display at the top of the control panel and this is used with the [<], [>], [ENTER/NEXT], [EXIT] and [EDIT/CLEAR] keys to provide an extensive menu system for access to various measurement modes.
  • Page 36 Prism Operation Manual Issue 2.00 There are nine options available at the top menu level in version 2.0 of the DSA-1 firmware. These options can be cycled using the [<] and [>] keys:       Select Mode: [>] Select Mode: [>]...
  • Page 37 [<],[>] toggle learn/display modes 9.4. Ref Learn Soft-cal for fs-measurement [ENTER],[CLEAR] acquire or clr cal 9.5. Battery Chg Starts fast-charge of battery [ENTER] skips discharge phase 9.6. Host Mode Interacts with host PC Figure 6.1. - DSA-1 V2.0 Menus Summary Page 6.3...

  • Page 38: Carrier Tests (Menu 1.)

    CARRIER panel is lit, and an asterisk appears to the right of the 'ppm' text the above display. For best accuracy, it is recommended that the DSA-1 be switched on for a few minutes before using `Ref Learn' and that the unit be similarly warmed up before making measurements.

  • Page 39: Fs Jitter (Menu 1.2.)

    PLL, which means that jitter below the PLL corner frequency is tracked by the PLL, and so cannot be measured. The DSA-1 PLL's corner frequency is displayed in the bottom right-hand corner of this sub-menu, and can be toggled between 700Hz or 1.5kHz using the [EDIT/CLEAR] key.

  • Page 40: Data Jitter (Menu 1.3.)

    Generator are unlocked but similar in frequency, readings may be unpredictable as the DSA-1 tries to fix onto the 'moving target'. When the Generator is on, the DSA-1 uses the Generator's Ref Sync as its own timing reference, therefore it is not restricted in low-frequency jitter measurement by the corner-frequency of the PLL.
  • Page 41 PLL, which means that jitter below the PLL corner frequency cannot be measured. The DSA-1 PLL's corner frequency is displayed in the bottom right-hand corner of this sub-menu, and can be toggled between 700Hz or 1.5kHz using the [EDIT/CLEAR] key.

  • Page 42: Amplitude (Menu 1.4.)

    Prism Operation Manual Issue 2.00 6.1.4. Amplitude (menu 1.4.) This selection measures the peak-to-peak differential carrier amplitude for either the co-axial input or the balanced input. The measurement is made regardless of lock state, and is displayed in volts or millivolts according to voltage.   Amplitude = 562mV...

  • Page 43: Errors (Menu 1.6.)

    Prism Operation Manual Issue 2.00 To return to the `Carrier Tests' level of the menu system, press [EXIT]. Note: The Eye Closure measurement is closely related to the 'Intersymbol' measurement in the version 1.0 firmware. However, the new Eye Closure measurement is more 'worst-case' (and so generally measures higher) since it also takes into account the effect of any fs jitter in narrowing the eye.

  • Page 44: Phase V Ref (Menu 1.7.)

    Phase v Ref (menu 1.7.) This selection measures the phase of the selected DI input signal with respect to the reference REF SYNC signal. The DSA-1 automatically selects whichever REF SYNC input is in use and also differentiates between Wordclock (SDIF-2) and AES11 format.
  • Page 45 Log. The summary is preceded by a description of the currently-selected DI input and its error status (as reported on the top line of the CARRIER panel). A typical entry might look something like this is the Results Log: Prism Sound DSA-1 Results Log: ------------------------------ *** BLOCK 01 ***:...

  • Page 46: Data Tests (Menu 2.)

    Prism Operation Manual Issue 2.00 6.2. Data tests (menu 2.) The following sections describe the Data tests; these functions allow examination of the audio and Channel Status data. There are seven different sub-menus, shown below, which can be selected using the [<] and [>] keys.      ...

  • Page 47: Audio Meter (Menu 2.1.)

    6.2.1. Audio Meter (menu 2.1.) The DSA-1 audio level meter displays incoming audio peak amplitude in a variety of different ways. In the default mode, a bargraph is shown in the lower half of the display with a dBFS scale in the upper half, as shown below:   40 .

  • Page 48: Active Bits (Menu 2.2.)

    Prism Operation Manual Issue 2.00 scale is lost through lack of space. In stereo mode, since one peak detector is shared between both channels, it is possible for transient peak readings to be missed. The numerical-readout, continuous-hold and stereo modes can all be selected independently;...

  • Page 49: C-S Fields (Menu 2.3.)

    (e.g. CD, DAT etc.) and can have a very large range of values. The DSA-1 recognises a very wide range of Category Codes and interprets them. The MS bit of the Category Code byte is interpreted in conjunction with the copy-prohibit bit in byte 0 and with the Category Code itself to determine SCMS (Serial Copy Management System) status.

  • Page 50: C-S Bytes (Menu 2.4.)

    Prism Operation Manual Issue 2.00 6.2.4. C-S Bytes (menu 2.4.) This selection allows examination of the incoming Channel Status data on a byte-by- byte basis, without any explanation or decoding. The display format is as follows:   CS,B14: 10111000 CS,B15: 00110110   Two bytes are shown at a time;...

  • Page 51: C-S Timecode (Menu 2.6.)

    Each of the timecode fields is decoded into an hours:minutes:seconds format with the units for the last digits dependent on the display mode as follows: the DSA-1 can decode Channel Status timecode data represented as a binary sample count (as defined in the interface standard) or as BCD (binary coded decimal) data.

  • Page 52: Log Data (Menu 2.7.)

    Prism Operation Manual Issue 2.00 6.2.7. Log Data (menu 2.7.) Entering this sub-menu causes a selection of Data Tests to be sent to the Results Log. The summary is headed by a description of the currently-selected DI input and the current sub-frame selection.

  • Page 53: Test Sequences (Menu 3.)

    Sequence Compiler software package on a PC. The program is then 'compiled' and downloaded into the DSA-1, after which it can be simply executed at the touch of a key. The order of the tests, the limits of acceptability, the displayed messages, and actions on failure can all be chosen by the programmer.

  • Page 54: Run (Menu 3.1.)

    Prism Operation Manual Issue 2.00 6.3.1. Run (menu 3.1.) Entering the `Run' sub-menu by pressing [ENTER/NEXT] causes the currently-selected Test Sequence to be executed. The progress of the Test Sequence is reported in the LCD display in a manner which corresponds to the programming of the Sequence. Each Test Sequence is divided into a number of 'Segments';...

  • Page 55: Select (Menu 3.2.)

    User test Sequence selected, Sys01 (the Global Test) is automatically selected instead. On power-up the DSA-1 selects whichever Test Sequence was current when the system settings were last saved (see section 6.9.2). This allows a preferred Test Sequence to be automatically loaded on power up.

  • Page 56: Log Sequence (Menu 3.3.)

    Log Sequence (menu 3.3.) The 'Log Sequence' sub-menu behaves exactly like the 'Run' sub-menu 3.1. (described above) except that the progression of the Test Sequence is recorded in the DSA-1 Results Log. A typical Test Sequence session might look something like this in the Results Log:...

  • Page 57: Generator (Menu 4.)

    GEN1 is generally the more fully-featured of the two, but 'locks out' certain other features of the DSA-1, principally the Carrier Tests. For this reason, GEN2 is provided as a 'Channel Testing' generator: GEN2 has less versatility than GEN1, but does provide the functionality required for Carrier-related tests, including jitter generation.
  • Page 58 When the desired sub-menu is displayed, press [ENTER/NEXT] to enter that sub- menu. Alternatively, to return to the top level of the menu system, press [EXIT]. HINT FOR SIMPLE USE OF THE GENERATOR: The DSA-1 Generator/Editor is very versatile in its features, but this can lead to problems if you accidentally select an 'advanced' generating or editing mode.
  • Page 59 Prism Operation Manual Issue 2.00 The table below contrasts the capabilities of DSA-1 Generators GEN1 and GEN2: Parameter GEN1 capability GEN2 capability Synchronisation Source Internal (44.1kHz/48kHz), Internal (44.1kHz/48kHz), AES11 (XLR or coax), AES11 (XLR or coax), Wordclock , or DI (in-line...
  • Page 60 Prism Operation Manual Issue 2.00 Figure 6.2. - Generator/Editor simplified block diagram Page 6.26...

  • Page 61: Sync Source (Menu 4.1.)

    In 'INT' (internal) mode, the DSA-1 generator is 'clock master', i.e. it is not synchronized to any external reference. The sample rate of the internal reference is selected in the second field as either 48kHz or 44.1kHz.

  • Page 62: Edit Modes (Menu 4.2.)

    Prism Operation Manual Issue 2.00 6.4.2. Edit Modes (menu 4.2.) The functionality of the Edit Modes sub-menu is mainly restricted to GEN1 mode, as selected in the Audio Function sub-menu, 4.3. The display format is:   Ù Editing [TIED] Aud:Y C-S:Y V:Y   The flashing arrow symbol indicates which parameter is selected for adjustment, and this selection is cycled using the [ENTER/NEXT] key.

  • Page 63: Audio Function (Menu 4.3.)

    Prism Operation Manual Issue 2.00 6.4.3. Audio Function (menu 4.3.) The Audio Function sub-menu is used to select which of GEN1 or GEN2 is active, and what function (or waveform) is selected for that mode. The display format is:   Ù...

  • Page 64: Audio Parameters (Menu 4.4.)

    Edit Mode were set to SPLIT. In that case, the 'A&B' indicator would be replaced by 'ChA' or 'ChB' according to the setting of the [CHAN] key. The word-length can generally be adjusted from 12 to 24 bits. The DSA-1 Generator is undithered, but is rounded and truncated to the selected word-length.

  • Page 65: Channel Status (Menu 4.5.)

    Prism Operation Manual Issue 2.00 GEN2 functions have fixed 24-bit word-length and fixed amplitude, with only the ON/OFF setting adjustable. Remember that the Audio output of the Generator is only presented at the Generator output so long as Audio editing is set in the Edit Modes sub-menu. If not, the Audio output is 'black' or transparent depending on the selected Sync Source.
  • Page 66 The timecode field edits are adjusted in a similar way to the alphanumeric label fields described above, but cycling from sub-seconds, to seconds, to minutes, to hours. The DSA-1 cannot inject dynamic timecodes, but only static patterns in either sample-count or BCD mode (as set in sub-menu 2.3. or 2.6.). Even so, a static timecode may still be useful in testing timecode receiving devices.

  • Page 67: C-S Capture (Menu 4.6.)

    To return to the `Generator' level of the menu system, press [EXIT]. 6.4.6. C-S Capture (menu 4.6.) On entering the C-S Capture sub-menu, the DSA-1 checks that the currently selected DI is locked (i.e. the CARRIER panel 'FAIL' LED is not lit). If so, the following message is displayed:...

  • Page 68: Valid Bit (Menu 4.7.)

    Prism Operation Manual Issue 2.00 allows the Generator Channel Status to be 'cloned' from a convenient or working source equipment, or used to over-ride the output of another equipment using 'in-line editing' mode. Note that if the captured Channel Status is in the professional format, a correct CRC is generated even if the incoming CRC was incorrect.

  • Page 69: Jitter Generator (Menu 4.8.)

    If the Sync Source is set to DI, the selected jitter is applied 'in-line' to the signal applied to the currently-selected DI input. Note that the possible amplitudes and functions of the applied jitter are quite limited in the DSA-1. The Prism Sound JM-1 is a high-quality analogue jitter modulator which Page 6.35...

  • Page 70: Log Generator (Menu 4.9.)

    On entry, the LCD shows:   Logging...   The current settings of the Generator/Editor are written to the Results Log. A typical result might be: Prism Sound DSA-1 Results Log: ------------------------------ *** BLOCK 01 ***: [Gen/Ed Setup:] Snc:INT Int:48 Editing [TIED] : Aud:Y C-S:Y V:Y A&B:Sine...
  • Page 71 Prism Operation Manual Issue 2.00 After logging is completed, the menu system automatically returns to the 'Generator' level. Page 6.37...

  • Page 72: Channel Check (Menu 5.)

    16-bit, 20-bit or 24-bit data. The test signal is the pseudo-random- sequence (PRS) waveform of the DSA-1's GEN2 (see section 6.4), which is similar to white noise at 0dBFS (full-scale) peak amplitude. The test signal contains different data for the two sub-frames.

  • Page 73: Run To Log (Menu 5.1.)

    The message on the bottom line indicates that the PRS data pattern has been successfully identified at the DSA-1's input. If all is not well, you may have some other message, most likely reporting that the Generator mode is incorrectly set or that the input is unlocked.
  • Page 74 005. 002:45:13.8 <END OF TEST> It is possible to set up the DSA-1 so that Channel Check Events are accompanied by the transmission of an Event-specific serial code from the RS-232 port. This is done by enabling 'Alarms' in the System Settings sub-menu as described in section 6.9.1.4.

  • Page 75: Setup (Menu 5.2.)

    [DO] key setting must be 'FNC'. Note that the Generator must be set as above even if the DSA-1 is only being used to check the test pattern and not to generate it (e.g. during remote or off-tape testing);...
  • Page 76 (e.g. gain adjustment, re-dithering, EQ etc.) will cause the test pattern to be corrupted. The DSA-1 monitoring loudspeaker can be used to quickly verify that the PRS is present at the test input;...

  • Page 77: Watchdog (Menu 6.)

    Setup mode is used to define the particular LEDs which are of interest, after which the Run to Log mode can be left unattended for as long as necessary to log any changes. By using the DSA-1 in 'loop-through' mode, in-line operation of the Watchdog mode is possible during normal operation of an installation.

  • Page 78: Run To Log (Menu 6.1.)

    Prism Operation Manual Issue 2.00 6.6.1. Run to Log (menu 6.1.) Before running the Watchdog to Log, it is necessary to use sub-menu 6.2. to 'alarm' the desired LEDs on the CARRIER and DATA panels as described in the following section (unless this information has previously been entered and saved with the system settings).
  • Page 79 006. 008:43:55.6 <END OF TEST> It is possible to set up the DSA-1 so that Watchdog Events are accompanied by the transmission of an Event-specific serial code from the RS-232 port. This is done by enabling 'Alarms' in the System Settings sub-menu as described in section 6.9.1.4. If Alarms and Key Beeps are both enabled, each Event is also accompanied by a beep from the DSA-1's loudspeaker.

  • Page 80: Setup (Menu 6.2.)

    Prism Operation Manual Issue 2.00 6.6.2. Setup (menu 6.2.) The Watchdog Setup mode is used to select which CARRIER and DATA panel LEDs are to be 'alarmed' prior to running the Watchdog to the Results Log. On entering Watchdog Setup mode, the LCD shows:   Select alarms on CARRIER and DATA...

  • Page 81: Microscope (Menu 7.)

    The output of this stage then has digital gain applied (from 0dB to +90dB) before being passed to the DO connector and the DSA-1's monitoring DAC. The [DO] key can be used to bypass the processing at the DO connector, allowing 'A/B' insertion of the programmed gain and masking.
  • Page 82 Prism Operation Manual Issue 2.00 is indicated per sub-frame by the appearance of 'A' and 'B' characters in the lower left- hand corner of the display. The [DO] key should normally be selected to 'RPT' when using the Microscope; selection 'loop-through' mode bypasses the digital processing, connecting DI directly to DO.

  • Page 83: Results Log (Menu 8.)

    The Results Log menu contains a variety of facilities for examining, clearing and printing the contents of the DSA-1 Results Log. The DSA-1 Results Log is an 4095-byte area of non-volatile memory which may be filled with various test results, settings etc. Each time some data is placed in the Results Log, it is marked with an 'Item Marker' which describes the source or type of entry.
  • Page 84 Prism Operation Manual Issue 2.00 The Results Log menu has six different sub-menus, shown below, which can be selected using the [<] and [>] keys.       8. Results Log [>] 8. Results Log [>] 8. Results Log [>] 8.1.

  • Page 85: Start Block (Menu 8.1.)

    6.8.2. Print Log (menu 8.2.) Entering this sub-menu causes the entire contents of the DSA-1 Results Log to be printed to a serial printer connected to the RS-232 port. After printing is completed, the menu system automatically returns to the Results Log level. Alternatively, the [EXIT] key can be used to halt printing part-way through.

  • Page 86: Clear Log (Menu 8.3.)

    Prism Operation Manual Issue 2.00 6.8.3. Clear Log (menu 8.3.) Entering this sub-menu brings up the message:   ENTER to confirm EXIT to cancel   Pressing [ENTER/NEXT] causes the Results Log to be cleared, followed by automatic exit to the 'Results Log' level; [EXIT] quits directly without clearing the Results Log. 6.8.4.

  • Page 87: Block Manager (Menu 8.5.)

    The [ENTER/NEXT] key causes the current Block to be printed on a serial printer via the RS-232 port. Note that the Log Header (the 'Prism Sound DSA-1 Results Log' message) is only appended to the first Block printed after entering the Block Manager.

  • Page 88: System Setup (Menu 9.)

    Note that certain parameters which were adjustable in the Settings menu (4.1.) in version 1.0 of the DSA-1 firmware, such as the jitter corner-frequency and the timecode display mode, are now displayed and adjusted directly within the measurement sub- menus to which they apply.
  • Page 89 Prism Operation Manual Issue 2.00 6.9.1.2. Coax output (menu 9.1. setting 2) OPTIONS: LOW, HIGH When the state of the [DO] key is 'RPT' or 'FNC' for re-clocking or signal generation, the output carrier amplitude at the BNC DO connector may be selected. The `HIGH' level voltage is 1V P-P for compatibility with the newly-proposed AES3-ID specification;...
  • Page 90 OPTIONS: ON, OFF In the ON state, this setting causes the DSA-1 to switch itself off if no keys are pressed for a period of five minutes during battery operation. In the OFF state, the DSA-1 will stay on until the battery is exhausted.
  • Page 91 (described in the previous section) where logged results may not need to be kept once they are printed. Operation of the DSA-1 Results Log is described in section 6.8. 6.9.1.9. Printer baud (menu 9.1. setting 9.)

  • Page 92: Save Setup (Menu 9.2.)

    Pressing [ENTER/NEXT] causes the following message to appear:   Saving...   After a few moments the saving is completed and the DSA-1 displays `OK' and sounds a `beep' on the loudspeaker (if beeps and speaker are enabled). The DSA-1 automatically returns to the `System Setup' menu.

  • Page 93: Defaults (Menu 9.3.)

    Pressing [ENTER/NEXT] causes the default operating parameters to be loaded, and the DSA-1 to restart in the 'Select Mode' (top level) menu. The action of loading the default parameters does NOT cause the power-up values in non-volatile storage to be overwritten;...

  • Page 94: Ref Learn (Menu 9.4.)

    In this state, the DSA-1 is said to have `learned' the external reference signal.

  • Page 95: Battery Charge (Menu 9.5.)

    If neither re-calibration nor clearing is required, press [EXIT] to return to the 'Settings' menu. For optimum precision, it is recommended that Ref Learn be used after the DSA-1 has been switched on for a few minutes. NOTE: The DSA-1 can be used measure the frequency of a Wordclock input by connecting the Wordclock to the coaxial REF SYNC input, entering the 'Ref Learn' sub-menu and selecting the fs display using [<] or [>].

  • Page 96: Host Mode (Menu 9.6.)

    Prism Operation Manual Issue 2.00 While the battery is discharging, all the LEDs on the CARRIER and DATA panels are lit and the DSA-1 controls are frozen. When the battery is fully discharged, the display changes to:   Battery charging...

  • Page 97: Using The Dsa-1 With A Host Pc

    The serial communications port of the DSA-1 allows for a variety of extended modes of operation. This section deals with some of the ways you can use the DSA-1 with a host PC, and describes the 'DSA-1 Host Support' suite of software supplied with the DSA-1.

  • Page 98: Ms-Dos Software Installation

    Prism Operation Manual Issue 2.00 7.1.2. MS-DOS software installation Place the DSA-1 Host Support diskette in drive A: (for example) and, at the MS-DOS prompt type: A:\INSTALL<Enter> Installation is then conducted automatically, prompting the user for any settings required, such as the preferred installation target directory name.

  • Page 99: Results Log Uploader/Editor Software

    7.2.1. Introduction This application is designed to allow the operator to upload the DSA-1 Results Log (as described in section 6.8) to a host PC. It is then possible to print the Log or import it into documents or reports.
  • Page 100 On selecting Upload, a dialog box appears prompting the operator to start the upload. It is necessary to ensure that the DSA-1 is connected to a COM port of the PC with a null-modem cable as described in section 3.6, and that it is in Host Mode (sub-menu 9.6.).
  • Page 101 Prism Operation Manual Issue 2.00 7.2.2.4. SEARCH menu The SEARCH menu contains the following options: Find Search for specific text Replace Search and replace specific text Next Perform the next search or replace action 7.2.2.5. WINDOW menu The WINDOW menu contains the following options: Tile Tile the editor windows Cascade...

  • Page 102: Test Sequence Compiler/Downloader Software

    7.3.2. Elements of a Test Sequence This section gives a brief overview of the structure of a DSA-1 Test Sequence. It is recommended that the reader refer to the listings of the built-in sequences in appendix C which provide a useful example.
  • Page 103 Prism Operation Manual Issue 2.00 The following example shows a very simple Segment called 'Carrier lock' which FAILS if the selected DI is unlocked, displaying the message 'No carrier lock'; otherwise the Segment PASSES. It would be unusual to write a Segment as simple as this, since normally a Segment contains a number of related tests rather than just one.

  • Page 104: Test Sequence Instruction Reference

    SEGMENT( 3, 'fs Tests The Segment end instruction has no parameters and causes the DSA-1 to skip to the beginning of the next segment, or to end the sequence if there are no more Segments...
  • Page 105 Prism Operation Manual Issue 2.00 7.3.3.3. Set switches These Instructions have no parameters and are used to set the DSA-1 switched operating parameters: Digital Input (DI) selection SELECT_COAX SELECT_XLR SELECT_OPT Sub-frame (channel) selection SELECT_CHANA SELECT_CHANB Jitter PLL corner-frequency selection SELECT_JITTERCF_HI...
  • Page 106 7.3.3.5. Measure numeric results These Instructions cause a test to be performed using the specified DSA-1 function, after which the numeric result is loaded into the Test Register in the units indicated. Some of the Instructions require that a 'time' parameter is specified which determines how long the measurement is averaged before loading the result.
  • Page 107 7.3.3.7. Sequence flow These Instructions cause the DSA-1 to branch or 'jump' to another part of the Sequence. Care should normally be taken never to branch outside the current Segment; although this is not specifically prevented, it is only occasionally useful and, if used unwisely, can cause unpredictable results.
  • Page 108 The value parameter can be expressed in a variety of units depending on what type of result is being tested. Usually there is a 'user-friendly' unit which requires the use of a suffix. Omitting the suffix causes the DSA-1's internal 'raw' units to be used: Time (MEAS_FS_JITTER, MEAS_DATA_JITTER, MEAS_EYE_NARROW) Use units of nanoseconds, with the suffix 'ns';...
  • Page 109 'PPM_320' if fs=32.0kHz Raw DSA-1 units are multiples of 1/64 Hz; Phase (MEAS_PHASE) Use units of degrees with a suffix of 'DEG'; Raw DSA-1 units are multiples of 360/512 degrees (about 0.703 degrees); JUMP_IF_GREATER_THAN( 45deg, @notinphase) is equivalent to JUMP_IF_GREATER_THAN( 64, @notinphase)
  • Page 110 Jump if flag is set to 'FAIL' 7.3.3.9. Miscellaneous This Instruction displays a message on the bottom line of the DSA-1's display. The text parameter must be enclosed in single quotes: Show the text on row 2 of the display.

  • Page 111: Using The Test Sequence Compiler/Downloader

    Using the Test Sequence Compiler/Downloader 7.3.4.1. Starting the program The DSA-1 Test Sequence Compiler/Downloader is started by double-clicking the appropriate icon in the 'DSA-1 Host Support' program group. A large editor window appears which is similar to any basic MS-Windows text editor such as Notepad.
  • Page 112 7.3.4.8 for details of the format of the list file. Download Download up to four User Test Sequences to the DSA-1 This option brings up a large dialog box containing a filename/directory listing, four edit boxes containing the '*.bin' wildcard filenames, a box containing the current COM port, and two buttons labelled 'Start' and 'Cancel': Page 7.16...
  • Page 113 PC in the dialog box. When the process is complete, the PC shows a message box to that effect, and the DSA-1's [EXIT] key can be used to quit Host Mode, at which point a 'Saving...' message appears briefly as any updated Sequences are stored in non-volatile memory.
  • Page 114 Prism Operation Manual Issue 2.00 7.3.4.6. WINDOW menu The WINDOW menu contains the following options: Tile Tile the editor windows Cascade Cascade the editor windows Arrange Icons Rearrange any icons representing minimized editor windows Close All Close all editor windows Save state Save the current state of the editor desktop to a disk file Restore state...
  • Page 115 Prism Operation Manual Issue 2.00 7.3.4.9. Compiler error messages The following error messages may appear in the List File: Not enough memory! The system cannot start the compiler as not enough memory is available. Close some active windows and try again. Data error writing output file xxxxx A disk error was encountered writing the .BIN file.
  • Page 116 Operation Manual Issue 2.00 Every Test Sequence must have a HEADER Instruction at the beginning. Refer to the DSA-1 Test Sequence Instruction reference. Message string too long! The required length for the text-string element of a HEADER and MESSAGE Instruction is 16 characters.

  • Page 117: Automated And Remote Operation

    Operation Manual Issue 2.00 7.4. Automated and Remote operation NOTE: The DSA-1 RS-232 port has the same pinout as a PC-AT COM port, so a null- modem cable (see section 3.6) should be used for Serial Slave operation (if the controlling device is an IBM-compatible PC), and for Macro Processor operation.
  • Page 118 Each Keyword is processed in sequence and causes an effect either within the DSA-1 or in the host PC. JUMP -type Keywords enable loops and other program flow changes.
  • Page 119 7.4.2.3.1. DSA-1 key presses These Keywords cause the DSA-1 to react as if the corresponding key had been pressed. This allows the user to navigate the menu system of the DSA-1 and to vary the key-controlled operating modes. LEFT or L 'presses' the DSA-1 [<] key...
  • Page 120 These keywords allow unconditional and conditional jumps to be made to another part of the macro sequence, depending on the state of the DSA-1 LEDs or the values in the internal stores (see above). They all specify a label to jump to:...
  • Page 121 Prism Operation Manual Issue 2.00 CHAN_A, CHAN_B, DO_LOOP, DO_RECLK, DO_FUNC, SYNC_CH, SYNC_BLK, SYNC_REF; Thus to jump if the sampling frequency was shown as 44.1kHz to a label '@good_fs', the Macro Command would be: JUMP_IF_LED(441, @good_fs) On contents of result stores: JUMP_IF_CHAR('c', @xxx) or Jump if the character specified is in JCHAR('c', @xxx)
  • Page 122 Copy the internal numeric store to STORE_VAR(n) numeric variable (n); n = 0 to 9. This Keyword is used to temporarily hold a value from the DSA-1 display or from the PC keyboard; Copy numeric variable (n) to the GET_VAR(n) internal numeric store;...
  • Page 123 \" Open the auxiliary COM port (other COM_OPEN than that used to communicate with the DSA-1); Print to the COM port currently open, COM_PRINT("...") tokens can be used as in the PRINT Keyword; Close the currently open COM port;...
  • Page 124 (this is the default state); Sets the Macro Processor execution SET_SPEED_SLOW speed to a slower rate (this makes the operation of the DSA-1 easier to observe); Cause a short 'beep' from the PC; BEEP Wait for n seconds before processing...
  • Page 125 An important consideration for the reliable operation of Macro Files is ensuring that the DSA-1 will operate in the same way each time tha Macro File is executed. It is therefore advised that the following steps are included at the start of any Macro File: Enter sub-menu 9.3.
  • Page 126 Prism Operation Manual Issue 2.00 The global Fail Flag can be used to indicate whether a particular test (or all tests) has passed or failed. This can be set or cleared during the macro sequence (initially it is clear) and tested using the JUMP_IF_FAIL or JUMP_IF_PASS Keywords. 7.4.2.5.
  • Page 127 It provides a quick method of generating a 'skeleton' Macro File by operating the DSA-1 manually. In Macro Recording mode, each time a key is pressed on the DSA-1 is translated into the appropriate Keyword and recorded to the specified filename. Text from the PC keyboard is also inserted into the file, so comments can be written marking DSA-1 navigation points in the Macro File.

  • Page 128: Downloading Firmware Updates

    The DSA-1's operating firmware is stored in a 'FLASH' memory within the unit. This allows the code to be updated without the need to open the DSA-1 case, or to replace any ICs. Instead, the host PC downloads the firmware from a floppy disk, so updates can be easily circulated.
  • Page 129 Prism Operation Manual Issue 2.00 It is wise to ensure that you have a copy of the existing firmware before updating, since you can reload the old firmware if you need to. Also, note that all setup options, User Test Sequences and the Results Log are automatically cleared as the new firmware starts for the first time.

  • Page 130: Test And Measurement Techniques

    Channel Status. However, there are many interesting exceptions which prove the validity of this rule! If you suspect a particular AES3 interface, a good first step is to patch the DSA-1 'in- line' (connect the source to the DSA-1's appropriate DI, and the DSA-1's DO to the receiver).

  • Page 131: Evaluating Equipment Outputs

    If the audio can be monitored correctly by the DSA-1 but not by the receiving equipment, try switching the DSA-1 into 'RPT' mode with the [DO] key.

  • Page 132: General Source Trouble-Shooting

    Having connected the source to the appropriate DSA-1 DI input, the first thing to check is whether the DSA-1 can lock to the source. This is indicated by the 'FAIL' LED going out and the CARRIER and DATA panels becoming active.

  • Page 133: Source Carrier Tests

    (for example 'starquad') has been used, that problems have resulted. By measuring the amplitude of the carrier with the DSA-1 set first to LO-Z and then to HI-Z, a source impedance factor can be approximated:...

  • Page 134: Source Data Tests

    Simple equipment should issue 'Valid' (Valid bit = 0, DSA-1 'V' LED OFF) all the time, although non-audio or compressed audio sources should show 'Invalid'. Uncorrectable errors or the STOP or PAUSE state in some transports may also result in 'Invalid' indications.

  • Page 135: Evaluating Equipment Inputs

    8.3.1. General receiver trouble-shooting A good general test is to use the DSA-1 GEN2 to inject an fs/4 tone into the input under test. The GEN2 Channel Status output should be set to 'professional' or 'consumer' according to the requirement of the input. The DSA-1 should generally be set to Internal Sync, but it may need to be locked to the 'house-sync' if that is expected by the input under test.

  • Page 136: Receiver Data Tests

    Prism Sound JM-1 Jitter Modulator is required. However, the DSA-1 can provide a useful set of jitter conditions at its output which allow jitter tolerance to be generally assessed. By selecting the DSA-1's GEN2 output, jitter can be applied in 1/8 UI steps from 0 to 3/8 UI (about 0 to 60ns P-P at fs=48kHz) and with a variety of jitter functions (waveforms).

  • Page 137: Evaluating 'In-Line' Performance

    DSA-1's appropriate GEN2 output to the input of the system under test, and the output of the system under test back to the appropriate DI input of the DSA-1. The DSA-1 generator would normally be set to Internal Sync. By selecting the fs/4 GEN2 function and monitoring using headphones or the built-in loudspeaker it is easy to hear sample-slipping or interpolated errors in the equipment or cascade.

  • Page 138: In-Line' Data Tests

    DSA-1 Ref Sync input. The phase can then be measured in the 'Phase-v-Ref' sub-menu, with the DSA-1 generator off.

  • Page 139: Evaluating Aes3 Cabling And Interconnects

    Microscope, the low-level signal can be monitored using headphones or the built-in loudspeaker (or by monitoring the DO output of the DSA-1). The best test signal is one with a steady decay, such as a synthetic 'bong' or solo piano music. If the re-dithering or noise-shaping is adequate, the decay sounds clean, with the signal disappearing into smooth and continuous noise.

  • Page 140: Evaluating A/D And D/A Converters

    DSA-1 'Channel Check' mode, which tests the correctness of every bit of every audio sample for as long as required. This test can be done using the DSA-1 to drive and receive the interconnect, but this method is not very useful since it tests the ability of the DSA-1 to transact data over the interconnect rather than that of the actual equipment normally connected to it.
  • Page 141 It cannot, however, assess resulting audio distortion and a conventional analogue or digital audio generator/analyser is necessary for this. To test the jitter susceptibility of a D/A converter, the DSA-1's GEN2 is connected to the converter input with the fs/4 audio function selected. Jitter is then applied using the fs/8 jitter function.
  • Page 142 The test can be done with an analogue distortion analyser if no FFT analyser is available. If the test is repeated using the DSA-1's PRS-L (audio-band noise) jitter function, the result is: Page 8.13...
  • Page 143 In this case, the trace is flat because there is no attenuation at any frequency. The above tests can also be applied to A/D converters by applying the DSA-1 jitter generator to the reference input of the converter and an analogue fs/4 tone just below clipping at the analogue input.
  • Page 144 Prism Operation Manual Issue 2.00 This test would normally be applied to a D/A converter though its normal cabling; the Jtest effectively is a test of both the cable and the D/A converter. THD+n for the non- attenuating D/A converter above is -73dB. Finally, it should be noted that the AES3 output and input tests detailed at the start of this chapter apply equally to the AES3 outputs and inputs of A/D and D/A converters respectively.

  • Page 145: Analogue Audio Pathfinding

    Prism Operation Manual Issue 2.00 8.7. Analogue audio pathfinding The DSA-1 can also be used to verify analogue audio paths. Monitoring of analogue signals is possible using headphones or the built-in loudspeaker, by setting the [LS MODE] to 'LINE'. No dedicated analogue generator is provided, but the digital generator can inject a passable analogue tone, even into a low-impedance line, by selecting the Jtest function (which has a strong 250Hz component).

  • Page 146: Specification

    Operation Manual Issue 2.00 Specification The following specification applies to DSA-1 units with hardware revision C or above, firmware revision 2.0 or above. Unless otherwise stated, quoted performances refer to XLR carriers at fs=48kHz. The specification is offered in good faith but is subject to alteration without notice.
  • Page 147 Prism Operation Manual Issue 2.00 Monitoring D/A converter: THD&n : 0.01%, -80dB (@1kHz,-0.5dBFS) Frequency Response: 20Hz-20kHz Outputs: Stereo 6.3mm headphone jack, plus internal loudspeaker TCXR (frequency) accuracy: ±3ppm 0-60C, as standard, ±0.5ppm to special order PLL responses: Loop filter -3dB LF corner at 700Hz/1.5kHz (reclocking and jitter Jitter gain at any frequency less than 1dB measurement)
  • Page 148 Prism Operation Manual Issue 2.00 DATA ANALYZER: Audio meter readout: Range, dBFS mode: -138dBFS to 0dBFS Accuracy, dBFS mode: ±0.01dB above -90dBFS ±0.1dB above -105dBFS ±0.5dB above -120dBFS Accuracy, HEX mode: absolute SIGNAL GENERATOR/EDITOR: Sync sources: AES11, Wordclock, Int (44.1kHz, 48kHz), AES3/IEC958 DI (in-line editing mode) Generator 1: Audio function:...
  • Page 149 Prism Operation Manual Issue 2.00 In-line edit mode: Audio, Channel Status and Valid bit may be independently edited or passed through Generator 2: Audio function: fs/4 sine, Jtest (cable-jitter stimulator), PRS (pseudo-random sequence, white noise); Channel Status: Professional or Consumer, with correct fs and Jitter generation: Function: PRS-H (wide-band noise), PRS-L (audio-band noise), fs/8 sine, long-cable-...
  • Page 150 Prism Operation Manual Issue 2.00 MICROSCOPE: Digital gain for examination of low-level signals, dithering schemes etc. Gain range: 0 to +90dB in 6dB steps Input word-length mask: 16, 20 or 24-bit Clipping indicators: A and B sub-frames independently RESULTS LOG: Non-volatile log capacity: 4095 bytes Logged functions:...

  • Page 151: Appendix A - Introduction To The Aes3 Interface

    D. The later parts of this section describe problems which often arise in practical applications of the interface. Section 8 discusses ways in which the DSA-1 can be used in diagnosis of equipment and interfacing problems.
  • Page 152 Prism Operation Manual Issue 2.00 This coding scheme is often regarded as a way of 'combining clock and data' on a single carrier. An 'NRZ' serial data scheme (such as SDIF-2) has only one 'cell' per bit, so a long series of 0s or 1s would be impossible to recover since it would not be possible to tell where one bit ends and the next starts.
  • Page 153 Channel Status error. For details of the functionality of the Channel Status fields, refer to the interface standards as listed in appendix D. Alternatively, the DSA-1's Generator Channel Status sub-menu 4.5. can be used to explore the possible settings.
  • Page 154 Prism Operation Manual Issue 2.00 3. Media format At the present time, there are four principal media in use for the AES3 format: Most professional installations currently use balanced, 110 cables terminated in XLR connectors. The transmitter is usually transformer-coupled and source-terminated, and the loaded voltage is usually around 4V P-P since RS422 drivers are most often used.
  • Page 155 Prism Operation Manual Issue 2.00 catalogued below are not the fault of the interface standard, but rather have resulted from its misuse by equipment manufacturers and system installers. Its inherent flexibility has often allowed problems to be created by unsuitable modes of use. 5.1.
  • Page 156 Prism Operation Manual Issue 2.00 Figure A.1. - Data Jitter mechanism This effect happens as a result of different pulse-lengths being present in the biphase- mark data - if the data segment had carried '111', the recovered transition timing would have been 'correct', just as for '000'.
  • Page 157 Prism Operation Manual Issue 2.00 Interestingly, although AES11 was devised to provide a better method of reference distribution than Wordclocks which had been used until that point, this is seldom the case since Wordclocks, even if their pulse-shape is terribly distorted by long and lossy cables, can be received without intersymbol interference because they carry a simple square-wave rather than a varying data pattern.
  • Page 158 Prism Operation Manual Issue 2.00 surprisingly turns out not to matter since most receiving equipment does not examine it anyway. Where the receiving equipment is capable of accepting a greater word-length than is being sent by the transmitting equipment, no problem results because no audio information is lost.
  • Page 159 Prism Operation Manual Issue 2.00 design and partly through the constraints placed upon them by various copy- management systems such as SCMS, as described below. 'Transparency' to the Validity, User and Channel Status bits is becoming an important issue as implementation levels rise. For example, most older AES3 digital-to-digital equipment produced its own Channel Status output pattern (usually only a partial implementation) which was unaffected by the incoming Channel Status, or was affected only by one or two input fields.
  • Page 160 Prism Operation Manual Issue 2.00 SCMS depends on the use of specially equipped recording machines which examine these bits on the incoming digital audio interface and act accordingly. For example, DAT recorders record two bits known as ID6 onto the recording medium according to the SCMS information passed from the source.
  • Page 161 There should be no need for most users to be concerned with the contents of this appendix, since application programs to operate the host modes are provided with the DSA-1. This section is intended for programmers who need to know how to operate the DSA-1's host modes from proprietary host equipment.
  • Page 162 The latest hardware version is 'C'; the latest firmware version is '200'. 3. Serial Slave mode This mode allows the host to control the 'keyboard' of the DSA-1 and to read the LCD display and LEDs. This mode is used by the Macro Processor PC software. Note that Serial Slave mode can be instated in the DSA-1 in any part of its menu system EXCEPT Host Mode (sub-menu 9.5.).
  • Page 163 0x00: SYNC O/P The availability of a 'dummy' key allows the HOST to poll the DSA-1 periodically to check that it is still connected and communicating successfully. Since there is no checksumming in the returned data this is recommended to maintain an accurate record of the state of the DSA-1.
  • Page 164 Operation Manual Issue 2.00 3.b) LCD text from DSA-1 In Serial Slave mode the DSA-1 echoes its LCD data to the HOST. This data is sent as raw ASCII without delimiters, and with no checksumming. The notional cursor is assumed to move one space to the right after each character. Allowable characters are in the range 0x20-0x7F and 0xA0-0xFF.
  • Page 165 (led data, low byte) (led data, high byte) ACK/NAK Each bit set in the data byte reflects a lit LED on the DSA-1. The CHARGE indicator cannot be sent. The LED codes are as follows: /* Bank 0 */ C_FAIL_LED 0x0001h;...
  • Page 166 3.f) Alarms In Watchdog or Channel Check modes, serial Alarm codes may be sent out by the DSA-1. This can happen even if Serial Slave mode is active. Refer to section 6. below for details of the Alarm messages. Page B.6...
  • Page 167 Operation Manual Issue 2.00 4. Test Sequence downloads In this mode, the HOST sends up to four User Test Sequences to the DSA-1 for storage in non-volatile memory. Each Sequence is 991 bytes long, i.e. shorter Sequences must be zero-padded by the downloader. Any or all of the four possible Sequence blocks may be updated during the download exchange.
  • Page 168 HOST. In the version 2.0 firmware, the DSA-1 transmits a variable number of bytes according to how much of the Log area is in use. Note that Results Log upload mode can only be instated in the DSA-1 if it is in Host Mode (sub-menu 9.5.).
  • Page 169 Prism Operation Manual Issue 2.00 '* CARRIER FAIL' 0x00 'Carrier Locked' 0x01 'Biphase Error ' 0x02 [ unallocated 0x03 'Near-Fail 0x04 [ unallocated 0x05 'Block Lgth Err' 0x06 [ unallocated 0x07 'Low-band Sense' 0x08 'Low-band Clear' 0x09 'fs = 32k0Hz 0x0a 'fs <>...
  • Page 170 Prism Operation Manual Issue 2.00 Appendix C - System Test Sequence Listings This appendix contains listings of the four System (built-in) Test Sequences. These are included as example source files with the Test Sequence Compiler software. You may find it useful to use one of these Test Sequences as a starting point in developing your own User Test Sequences.
  • Page 171 Prism Operation Manual Issue 2.00 SET_FAIL; MESSAGE('44056, >1000ppm '); SEGMENT_END; @not_440: JUMP_IF_GREATER_THAN(3,@not_32); MEAS_FS_ERROR; AND(07FFFH); JUMP_IF_GREATER_THAN(1000ppm320,@bad_32); SEGMENT_END; @bad_32: SET_FAIL; MESSAGE('32kHz, >1000ppm '); SEGMENT_END; @not_32: SET_FAIL; MESSAGE('Non-standard fs '); SEGMENT_END; /************************************************************************/ Segment 3: tests amplitude according to input medium SEGMENT( 3,'Amplitude SET_PASS; TEST_OPT; /* do not test if optical input */ JUMP_IF_ZERO(@not_opt);...
  • Page 172 Prism Operation Manual Issue 2.00 SET_PASS; SELECT_EYE_AT_ZEROX; MEAS_EYE_NARROW(30); /* test for 3s */ JUMP_IF_LESS_THAN(40ns,@int_ok); MESSAGE('Smearing >40ns '); SET_FAIL; @int_ok: SEGMENT_END; /************************************************************************/ Segment 6: tests for non-audio channel status SEGMENT( 6,'Non-audio SET_PASS; TEST_CSBYTE(0); AND(02H); JUMP_IF_ZERO(@cs_ok); MESSAGE('Non-audio CS '); SET_FAIL; @cs_ok: SEGMENT_END; /************************************************************************/ Segment 7: tests for any parity or biphase errors during the test sequence SEGMENT( 7,'Biphase errs');...
  • Page 173 Prism Operation Manual Issue 2.00 Segment 2: tests for consumer channel status SEGMENT( 2,'Consumer CS '); SET_PASS; TEST_CSBYTE(0); AND(01H); JUMP_IF_ZERO(@cs_cons); MESSAGE('CS not consumer '); SET_FAIL; @cs_cons: SEGMENT_END; /************************************************************************/ Segment 3: tests for a standard sampling rate, within 1000ppm SEGMENT( 3,'fs frequency'); SET_PASS;...
  • Page 174 Prism Operation Manual Issue 2.00 @not_coax: MEAS_DIF_AMPL; /* XLR ampl (> 400mv, <7V JUMP_IF_GREATER_THAN(7V,@xlr_tobig); JUMP_IF_GREATER_THAN(400mv,@xlr_done); SET_FAIL; MESSAGE('XLR ampl <0.4V'); @xlr_done: SEGMENT_END; @xlr_tobig: SET_FAIL; MESSAGE('XLR ampl >7.0V'); SEGMENT_END; /************************************************************************/ Segment 5: tests for fs jitter within 20ns p-p, data jitter within 40ns p-p SEGMENT( 5,'Jitter SET_PASS;...
  • Page 175 Prism Operation Manual Issue 2.00 Sequence 03: General Professional Test This Sequence requires Professional Channel Status and applies general professional limits similar to AES3-1992: HEADER( 'General Pro Test'); Segment 1: tests carrier for lock, near-fail, block-length, and analogue SEGMENT( 1,'Carrier qual'); CLEAR_ERROR_COUNT;...
  • Page 176 Prism Operation Manual Issue 2.00 @not_440: JUMP_IF_GREATER_THAN(3,@not_32); MEAS_FS_ERROR; AND(07FFFH); JUMP_IF_GREATER_THAN(50ppm320,@bad_32); SEGMENT_END; @bad_32: SET_FAIL; MESSAGE('32kHz, >50ppm '); SEGMENT_END; @not_32: SET_FAIL; MESSAGE('Non-standard fs '); SEGMENT_END; /************************************************************************/ Segment 4: tests amplitude according to input medium SEGMENT( 4,'Amplitude SET_PASS; TEST_OPT; /* do not test if optical input */ JUMP_IF_ZERO(@not_opt);...
  • Page 177 SEGMENT_END; /************************************************************************/ END; Sequence 04: Strict Professional Test This Sequence is recommended by Prism Sound for use in professional installations. It requires good electrical and timing margins, and a full Professional Channel Status implementation: HEADER( 'Strict Pro Test '); Segment 1: tests carrier for lock, near-fail, block-length, and analogue SEGMENT(1,'Carrier qual');...
  • Page 178 Prism Operation Manual Issue 2.00 MESSAGE('Carrier nr fail '); SEGMENT_END; @carr_ok: TEST_BLOCKERR_BIT; JUMP_IF_EQUAL(0,@block_ok); MESSAGE('Block length err'); SEGMENT_END; @block_ok: TEST_ALOG_BIT; JUMP_IF_EQUAL(0,@not_alog); MESSAGE('Analogue signal '); SEGMENT_END; @not_alog: SET_PASS; SEGMENT_END; /************************************************************************/ Segment 2: tests for professional channel status SEGMENT(2,'Pro CS SET_PASS; TEST_CSBYTE(0); AND(01H); JUMP_IF_NOT_EQUAL(0,@cs_prof); MESSAGE('CS is consumer SET_FAIL;...
  • Page 179 Prism Operation Manual Issue 2.00 @coax_ok: SEGMENT_END; @coax_above: SET_FAIL; MESSAGE('Coax ampl >2.0V'); SEGMENT_END; @do_xlr: MEAS_DIF_AMPL; /* XLR ampl , > 400mv, <7V*/ JUMP_IF_GREATER_THAN(7V,@xlr_above); JUMP_IF_GREATER_THAN(400mV,@xlr_ok); /* too low */ SET_FAIL; MESSAGE('XLR ampl <0.4V'); @xlr_ok: SEGMENT_END; @xlr_above: /* too high */ SET_FAIL; MESSAGE('XLR ampl >7.0V');...
  • Page 180 Prism Operation Manual Issue 2.00 @emph_ok: TEST_CRCERR_BIT; /* CRCC not correct? */ JUMP_IF_EQUAL(0,@crc_ok); MESSAGE('CRC error '); SET_FAIL; SEGMENT_END; @crc_ok: TEST_CSBYTE( 0 ); /* src sampling frequency unlocked? */ JUMP_IF_MASKED(20h , @src_lock ); MESSAGE('Source unlocked '); SET_FAIL; SEGMENT_END; @src_lock: TEST_CSBYTE( 0 ); AND(0C0H); /* Channel Status fs <>...
  • Page 181 Prism Operation Manual Issue 2.00 Appendix D - References Interface standards documents: AES3-1992 - ` Recommended Practice for Digital Audio Engineering - Serial Transmission Format for Two-Channel Linearly Represented Digital Audio Data' J. Audio Eng. Soc., Vol 40 No. 3, pp 147-165 (June 1992) The 'AES/EBU' professional interface standard IEC958 - `Digital Audio Interface' International Electrotechnical Commission 1989...
  • Page 182 Audio', the Proceedings of the 10th International AES Conference, London, September 1991. pp 115-126 [10] Julian Dunn and Ian Dennis, Prism Sound, - `The Diagnosis and Solution of Jitter-Related Problems in Digital Audio Systems' Preprint 3868, presented at the 96th AES Convention, Amsterdam, February 1994.
  • Page 183 Prism Operation Manual Issue 2.00 Index 15/50 emphasis indicator ......... . . 4.5 2-CH indicator .
  • Page 184 Prism Operation Manual Issue 2.00 Cable effects ........... . . 6.6 Cable types .
  • Page 185 Prism Operation Manual Issue 2.00 Control interactions ..........5.3, 5.4 COPY PRO indicator .
  • Page 186 Prism Operation Manual Issue 2.00 Amplitude ..........6.30 Audio Function .
  • Page 187 Prism Operation Manual Issue 2.00 Layout, controls and connectors ........2.1 Level meter function .
  • Page 188 Prism Sound DA-1 ..........8.13 Prism Sound Dscope system ......1.1, 2.3, 8.10, 8.12 Prism Sound JM-1 Jitter Modulator .
  • Page 189 Prism Operation Manual Issue 2.00 SDIF2 Wordsync ..........3.3 Self-calibration .
  • Page 190 Prism Operation Manual Issue 2.00 User Test Sequences Compiling ..........7.16 Writing .

Table of Contents