dScope Series III FAQ, Tips and Techniques
|What is "D/A line-up"?
|The D/A line-up enables the dScope to show analogue amplitudes in digital units, or vice versa. To do this, it needs to know the analogue equivalent of a full-scale digital signal (0dBFS). The D/A line-up field allows this to be specified.
For example, if your Equipment Under Test (EUT) has a maximum output level of 24dBu, you could generate or analyze signals at -1dBFS, which would be 1dB below the maximum output level of the device.
For a fuller discussion of D/A line-up, see this technical note.
|My dScope was working properly, but now the computer can't seem to connect to the dScope hardware.
|This is most likely to happen when the power management settings allow the operating system to turn off the power to the USB ports. To fix this,
|No signal/the wrong signal is coming out of the dScope's outputs.
|Check that the outputs are turned on. This may be done using the Signal Generator panel, which has On and Off buttons for each channel.
If the digital outputs are not working, then open the Digital Outputs panel and check that they are not muted. For analogue outputs, open the Analogue Outputs panel and check that they are not muted.
If using BNC connectors, check that they are plugged into the correct digital or analogue output connectors (and not the Monitor Outputs, which also have BNC connectors).
|How do I configure the dScope inputs and outputs for balanced/unbalanced operation and grounding?
|The dScope has very flexible input and output circuitry and it is important to make sure that it is configured correctly for the measurement you wish to undertake.
For more details, please see this technical note.
|dScope FFT measurements are very slow or not triggering.
|There are a couple of things that can cause this. The most obvious is that the signal level is not sufficient to cause it to trigger. Check the trigger point in the "FFT parameters" dialogue. Also large FFTs simply take longer to capture and process.
Another possibility is that, with analogue signals with significant variation in amplitude, the auto-ranging is preventing the device from capturing a whole buffer of data before the input range changes. The dScope automatically rejects any buffer of data that contains a gain range change. If the signal varies in level rapidly such as white or pink noise, it may make it difficult for the dScope to get a clean buffer.
To prevent this, you can set the auto-ranging step size to medium (6dB) or coarse (20dB) in the Analogue Inputs dialogue or turn auto-ranging off altogether.
A further possibility is that, with an analogue connection on a DC coupled dScope hardware or with a digital input, there may be sufficient DC offset to prevent smaller signals from passing through 0V (the default trigger condition is a positive going zero crossing). You can get round this by using "continuous" triggering or changing the trigger conditions in the FFT parameters dialogue.
|Can I measure phantom power with the dScope?
|No. The dScope inputs are AC coupled. You can however measure phantom power with the dS-NET IO Switcher.
Phantom power will not damage the dScope outputs provided the series current limiting resistor in the device under test is in place. Measurements can typically be made with phantom power turned on.
You will not be able to measure phantom power with the device connected to the dScope output, however unless the analogue outputs are muted. Even if the output is muted, there will still be a resistance between pins 2 and 3 although this is floating relative to ground. See also the analogue outputs architecture page. for more information on this.
|Is Prism Sound calibration traceable to international standards?
|Yes. The Prism Sound calibration standards and traceability document is available here.
|My dScope is showing a reading of "-INF dB". What does this mean?
|-inf is short for -infinity and means that the reading could not be calculated in dB. There are two main scenarios when a dScope will display -inf:
|What were dScope Series I and dScope Series II?
|The original Prism Sound dScope dates from 1993 and was an ISA Card based system for analysis of digital audio that ran under DOS. A single ISA card could do generation or analysis but not both. Fitting two ISA cards allowed generation and analysis in a single computer. This was around the time when a 486DX computer with 4MB of RAM was high tech.
An upgrade to the software to version 2 in 1995 brought significant advances to the generator and automation of the system and became known as dScope 2.
When the external USB connected hardware dScope was announced in 2003, it was named dScope Series III to avoid confusion with the original dScope hardware with version 2 software. dScope Series III is a huge step on from dScope Series 2 as it is a full digital and analogue audio analysis system with a particularly "soft" software architecture that makes it extremely flexible for devising custom measurements and automating test processes, as well as incorporating all the standard audio measurements in an accessible way.
|Why does my signal look all jagged at high frequencies?
|When displaying the audio waveform on the trace window, dScope Series III plots each sample as a single data point and draws straight lines between them. At frequencies approaching the Nyquist frequency the waveform will appear jagged as there are very few samples per cycle of the waveform. This is not a fault and doesn't mean that the audio is distorted. It is just that we don't currently attempt to plot what the waveform might have looked like before sampling, or what it could look like after a reconstruction filter, but only plot the data we actually have.
|How do I install the software from the web download?
|Download the ds3_VXXX.exe file (where 'XXX' represents the software version number). Double-click on it. This will extract all the installation files into a temporary directory and then run the 'setup' program. Follow the on-screen instructions.
The current release of the software is available from the Downloads page.
|How do I Install the software from the CD?
|Insert the CD into your CD drive. If you have 'Auto-run' enabled, then the installation will start automatically. Follow the on-screen instructions. If 'Auto-run' is not enabled, select the 'Run' option from the Start menu. Type in 'D:Setup' (where D is the drive letter of your CD-ROM drive) and click OK to start the installation. Follow the on-screen instructions.
Note that on Windows XP, the process is slightly different. As with other operating systems you must install the dScope software before connecting the hardware. The installation differs in that Windows XP requires device drivers to be digitally signed by Microsoft, which the dScope drivers currently aren't. After you have installed the dScope software and connected dScope for the first time, Windows XP will bring up the "Found new Hardware" wizard. Simply select "Next" at each point in this wizard to allow the device driver to be automatically loaded.
During the installation, you may be warned that the dScope device driver has not passed Windows Logo testing. Simply click "Continue" and the installation process will continue.
|What is Windows Logo testing, and how does it affect the dScope?
|For seamless installation into the Windows XP operating system, Microsoft requires that Device Drivers are digitally signed (indicating that they have been approved by Microsoft). The dScope drivers are not currently signed, because the signing process cannot easily be reconciled with the dual-driver "re-enumeration" process that the dScope uses. This dual driver/re-enumeration arrangement means that device firmware can be easily downloaded into the dScope in the background when it is first started up. It also allows new firmware to be shipped with new software releases if necessary.
We are currently investigating the process for getting our device drivers signed by Microsoft, but for the time being, the installation process will require you to step through the "Found New Hardware" wizard when the software is first installed. During the installation, you may be warned that the dScope device driver has not passed Windows Logo testing. Simply click "Continue" and the installation process will proceed.
|When I plug in the hardware, it brings up the 'Found new hardware' wizard. What do I do?
|Firstly, make sure that the dScope software has been installed. If not, then Select "Cancel" from the wizard and install the software from the CD or the web download.
On Windows XP, the 'Found new hardware' wizard will display even if the dScope software has been installed. Simply select "Next/Finish" for each page of the Wizard, until the installation is completed.
|Why does Windows find the hardware twice when it is first installed?
|The dScope system works by behaving as two separate hardware units. When it is first switched on, a loader driver will load (dsloader.sys) which downloads some firmware into the dScope hardware. The hardware then tells Windows that it is new hardware, and the usual dScope driver (dsusbdrv.sys) will load. In this way, new releases of the dScope firmware can be shipped with software, and the hardware does not need to be upgraded when new firmware becomes available.
|When I switch on the hardware for the first time, the 'Found New Hardware' wizard tells me it can't install the hardware.
|You need to install the dScope software first. Ensure that the hardware is switched OFF while you do so.
|When I run the dScope software, it can't find the hardware.
|Check that the hardware is switched on, and the USB is connected - the 'on' LED should be red. If you plugged in the hardware before installing the software, then Windows will not have linked the dScope hardware to the software correctly. Switch off the hardware, un-install the software, and restart Windows. Then install the software again, and turn on the hardware.
If you are still experiencing problems then please contact Prism Sound.
If the hardware has been working properly but has since stopped, then see also the FAQ in the "General Questions" section entitled 'My dScope was working properly, but now it can't contact the hardware'
|I deleted an old version of dScope, and now the software won't install.
|If the software is simply deleted rather than un-installed, Windows thinks that the software is still there because it still has references to it in the registry. The new installation tries to un-install it but since it doesn't exist, the installation fails. To fix this, please see this technical note.
|During the installation, I get a message that says 'Error 1904.Module C:WindowsSystem32ScriptDlg.dll failed to register. HRESULT -21470224770. Contact your support personnel.'
|On Windows 2000 and XP, the ScriptDlg.dll ActiveX control used with the dScope Scripting system can fail to register. This may be because the installation has been performed without Administrator privileges. Try un-installing the software, then log on as an Administrator and re-install the software.
Alternatively, you can manually register the DLL after installation. Select 'Ignore' to the error message, and the installation of the rest of the software will continue successfully.
After installation, select 'Run' from the Start menu. Type in the following: regsvr32.exe ScriptDlg.DLL to manually register the control.
|When I run another program, I get a message saying 'dScope Series III -Preparing to install' before the program runs.
|This can occur if a previous installation has been cancelled. To fix this problem, you need to clean out the registry entries that make Windows think the old dScope software is still installed. For details of how to do this, please refer to this technical note.
|When I switch on the dScope software, it recognises a USB device 'Prism Sound dScope Series III - uninitialised (dsloader.sys)' but then doesn't get any further.
|We have found that a certain notebook PC (Compaq Evo N1015v) exhibits this problem. We are not aware of any other machines that this is a problem on.
The reason is a high capacitance in the host end of the USB link, and can usually be fixed by using a shorter USB cable.
|I know there has been a new software release, but I haven't been informed about it.
|If you register your dScope we will keep you informed of major software releases and upgrades by email. You can register your dScope here
Alternatively, there is an RSS feed specifically for the dScope Series III software. You can subscribe to the one appropriate to your operating system (32bit or 64bit) on the dScope downloads page. This provides a means for checking automatically for any updates to the dScope Series III software, not just major updates.
|Does dScope Series III work with Windows 7 or 8?
|From version 1.21 dScope will work with Vista and Windows 7 or 8 32bit editions. From version 1.40 64 bit operating systems are also supported. There are two versions of 1.4x software, one built for 32bit systems and one built for 64bit. Please make sure you use the right one for your operating system.
|Can I try the software without the hardware?
|Yes, although obviously you won't be able to make any measurements. The software is free and running it is one of the best ways of finding out about dScope. It can be easily un-installed using the Windows "add/remove programs" dialogue.
You can also have the software installed on as many computers as you like and you don't have to register the installations.
You can download the latest version of dScope software here.
|Do I need to un-install the old software before installing a new version?
|No. The installer will update your installation looking after all this for you and will not remove your configurations or scripts etc.
If you make changes to the supplied scripts or configurations, however, you should save them with a new name or they will be overwritten when a new version is installed.
It is good practice to keep backups of your important files in any case, and we recommend this is done before you upgrade your installation of dScope.
Note also that if the dScope is being used in a "mission critical" application, you should test any new software off-line with your scripts and configurations before applying it. Note that configurations saved with newer software versions can not normally be loaded into older versions of dScope software, but older configurations can be loaded into newer versions of software.
|What is "Encoded Stream Generation"?
|This refers to the ability of the dScope generator to play out digital streams that are encoded with Dolby Digital or DTS. These are stored as wavetables that are pre-encoded and can be selected from an interface that simplifies the selection of the required waveform.
Due to its size (in MB), this feature is not automatically included in the dScope software, but is included as a separate download. The download includes an installer that adds the files and the user interfaces to an existing dScope installation.
More information is available on the Encoded Streams application page available here.
|How do I update the dScope firmware?
|You don't need to. The firmware is automatically managed by the software behind the scenes.
When you update the software, it will automatically update the firmware if necessary when it is run for the first time. It does this in the few seconds while the "Accessing Hardware" message is on screen when you first start the software.
|How do I go back to a previous version of software?
|Occasionally it may be necessary to go back to a previous version of software, particularly if there are scripts or configurations which don't yet work with the new version. To do this, you will need to:
When you first run the newly installed software, you may need to run it "as administrator" once so that Windows registers the automation interfaces.
|Which operating systems are supported?
|dScope Series III software is available as 32 and 64bit versions for Windows operating systems with USB support. Supported operating systems include:
|Where do I get the licence file for my dScope Series IIIA+?
|The licence file for the dScope Series IIIA+ is included on the CD that shipped with the hardware. This is installed automatically if you install the software from the CD.
In order to use the "plus" features of the dScope Series IIIA+ this licence file needs to be present in the dScope installation folder which is typically C:\Program Files\Prism Sound\dScope Series III. If you installed the software from a different CD or from a file download, the licence file will not be present. To fix this, simply copy the licence file from the CD: it will be in the "Licences" folder and will be called "dScopeLicence_xxxxx.txt" where xxxxx is the serial number of the dScope. Place a copy in the dScope installation folder of any computers that you want to use the hardware with. Any one computer can have multiple licence files.
|Why doesn't my dScope Series IIIA+ have the "plus" features?
|The dScope Series IIIA and IIIA+ are the same hardware, but the functionality of the software is determined by a licence key. Without the licence key, the unit will behave as a dScope Series IIIA with reduced functionality. The licence key is a text file that is tied to the serial number of the dScope and should be present in the dScope Series III folder of the host computer (typically C:\Program Files\Prism Sound\dScope Series III) and is named "dScopeLicence_xxxxx.txt" where xxxxx is the serial number of the dScope. The licence key is supplied on the installation CD that is sent with the dScope Series III hardware and is normally installed automatically if the software is installed from the CD. If you installed from another CD or from a file download, or are using a different computer that doesn't have the licence file installed, it will behave as a dScope Series IIIA with reduced functionality. To remedy this, you need to copy the licence file from the installation CD (it can be found in "Licences" folder on the CD) to the program folder mentioned above.
|What is dS-NET?
|dS-NET is a communication protocol used by the Prism Sound dScope Series III to control peripherals. It is a proprietary, open protocol which can use RS232 or RS485 hardware. In practice, on the dScope it is normally configured to run with RS232. It is possible to use a PC serial port to control any dS-NET device.
For more information, see this technical note.
|Can I control dS-NET peripherals from a PC serial port?
|Yes, however we do not provide any software to do this as the control of the peripherals is integrated into the dScope software.
If you wish to do this, you will need to set up the control of the devices manually using the dS-NET protocol which is available here.
|Where can I find details of the dS-NET protocol?
|The dS-NET protocol is available here.
|What are the Analogue Only dScopes?
|Until 2009, all dScope Series III units were dual domain analogue and digital units. In recognition that many applications do not have any digital component and therefore the digital sections are superfluous, the Analogue Only dScope Series III was introduced. This is in two versions dScope Series IIIA and dScope Series IIIA+. The "Plus" variant has all the analogue functionality of the full dScope Series III, whereas the IIIA has reduced functionality. The IIIA and IIIA+ are the same hardware, but the IIIA+ has a licence key (supplied on the software CD) to enable the full feature set.
Please see the dScope Series III Features Page which has a table detailing the functionality of each variant.
|My computer loses contact with the dScope. What can I do?
|Symptoms of this include readings that show -INF, -300dB or 0.0000% (i.e., there is not data coming back from the hardware to display). Once in this state, the readings don't update until the software is re-started. There may or may not be a message saying that the software has lost contact with the hardware. This may happen periodically once the dScope is running, or it may happen on start-up.
USB hub power management
The main cause of the dScope losing contact with the hardware is Windows turning off power to the USB root hubs within the PC. The first thing to check is that the settings in the USB Hub power management are set to prevent this:
In most cases, turning off the power management as above will fix the issue, however we have heard of a few instances when the dScope software loses contact with the hardware periodically, even though this setting is correct. There appear to be two different scenarios:
|How do I change the mains fuse or mains voltage?
|Please see details here.
|My TOSLINK digital connections don't work above 96kHz sample rates. Is this right?
|Yes. It's not a fault. Sample rates above 96kHz are not part of the TOSLINK standard that dScope implements. The digital outputs dialogue allows you to set sample rates above this because the outputs are paralleled with the AES3 and S/PDIF outputs which can support these rates. Some dScopes can connect on the TOSLINK connection above 96kHz depending on the components fitted and the interconnecting cable, but this should not be relied upon and is not part of the specification.
|Are dScope Configurations backwards compatible?
|Yes, you can load older Configurations into newer versions of dScope software. The reverse is usually not true: Configurations saved with a newer version of software often can not be loaded with older versions of software.
Configurations created with dScope Series III may not be able to load entirely into dScope Series IIIA or IIIA+(Analogue Only units), and some configurations created with dScope Series IIIA+ may not load entirely into dScope Series IIIA. This is simply because of the feature sets available in the different models.
|How do I get started with dScope?
|For a quick start guide to using dScope for the first time, please see this technical note.
|I want to open a lot of windows, but don't have enough space on the screen.
|The dScope display has five separate 'Pages' that can contain different windows. For example, you may wish to have the Trace window open on one Page, Signal Analysis details on another, and the generator setup on yet another Page.
In addition to this, parts of a large settings window can be dragged off using the mouse to create a smaller window containing only the details you are interested in.
|How do I get started using VBScript?
|To find out how to use the VBScript language, you can download a VBScript help file directly from the Microsoft web site. Please note that this link moves periodically. If it doesn't work, try searching the Microsoft site for script56.chm
See also the Getting Started with Scripting page on this web site which in turn links to other scripting resources.
|How do I access the 'My Documents' directory from a script?
|You need to use the Windows Shell object from your script, to access the Special Folders. Further information on the Window Shell object can be found in the Microsoft MSDN WSHShell Object Documentation
|Under Asian versions of Windows, the 'Applications' button gives an error message and doesn't run.
|The symbol used to denote 'microVolts' ("µ") is treated together with the character after it as a special symbol (e.g. a Chinese character). When Asian versions of Windows are used to run the script, the character in the script is interpreted as a special symbol, which stops the script from being interpreted correctly.
To fix this, open the '< dScope >/Scripts/Automation/AES17/AES17_Useful.dss' script using the dScope Script Edit window. Near the top, you will find a line defining 'strMicro' as a constant. You need to change the line from:
Const strMicro = "µ"
Const strMicro = "u"
This will cause the script to use a standard character (the letter 'u'), so it won't be interpreted as a special symbol.
|How do I use files and folders from my script?
|Most of the things you need to do with files and folders can be achieved using the File System Object. For more information, see Microsoft MSDN documentation on the FSO
|I can't control Microsoft Office applications from my script.
|Access and Excel can be automated from the dScope using the DAO (Database Access Objects) object. If scripts using this object do not run correctly, then firstly check that these Office applications were installed with 'Database Access Objects' selected.
Older versions of the DAO object could be created using CreateObject("DAO.DBEngine") . This would automatically access the latest version of the engine found on the machine. However, in later versions of Microsoft Office, Microsoft has renamed this object with a specific version number, for example "DAO.DBEngine.35 " or " DAO.DBEngine.36 ". You will need to create this more specific object for the script to work.
|When I start up the dScope from another application (e.g. Visual Basic), I get a run-time error. Why is this?
|When you start the dScope software from another application, you must give it time to initialize before trying to access any of the dScope`s properties or methods. To do this, use the `IsInitialized` function.
|I need to automate some tests, but I don't have time to write scripts myself. What do I do?
|Prism Sound offers an application development service in which staff engineers will assist with code development for test automation.
Please contact Prism Sound on +44 (0)1353 648 888, or email us at email@example.com
|Where can I find examples of scripts and scripting techniques?
|There is a selection of scripts and examples available on the scripting page.
|Why is my script returning inaccurate results?
|If your results retrieved from a script appear to be erratic and variable, check that the "Use settling details when getting Result values from scripts" option is enabled. This is checked by default and there are very few instances when it should be disabled.
With this option unchecked, the script will get the first results that the dScope has, without any checking being done that the results are settled. This will tend to give very fast readings, but they might not be stable settled results.
This option is found in the "Utility" menu under "Options" in the "Miscellaneous" tab.
|How do I get started automating dScope?
|There is an introduction to dScope scripting and automation available here.
|How do I create a scripted user interface?
|It is possible to create a flexible and powerful scripted user interface using the "Script Dialogue" DLL provided with dScope. This provides a means to produce a user interface from VBScript including such things as buttons, checkboxes etc.
For an introduction to the features of the Script Dialogue control (ScriptDlg.dll), please see Creating Custom Controls using ScriptDlg.DLL. Full documentation is available in the dScope Scripting manual available as a PDF download from the downloads page, or in the ScriptDlg.DLL CHM help files available here. Note that the ScriptDlg reference is also included in the dScope help in the "Scripting Manual" section under "The ScriptDlg ActiveX control". Many of the dScope applications are scripted using this control so they are a good source of examples of how to use it.
The syntax colouring files for Crimson Editor available from the downloads page include the necessary keywords for ScriptDlg methods, properties and events.
|I'm getting Runtime Error 429: "ActiveX Component Can't Create Object" errors, what's wrong?
|This happens when attempting to automate dScope from an external application using ActiveX/COM on Windows Vista or later system when the dScope object hasn't been registered with the system as an automation server. You should find that running the dScope application "as administrator" will do the necessary registration and you will then be able to use your external automation. Do this by right-clicking on the dScope short cut and selecting "Run as Administrator". Note that just being logged in as an administrator and running the dScope software is not sufficient. You may need to close the program and restart it before this takes effect, but you should only need to do this once.
|How can I speed up my automated test?
|There are quite a few things to look out for when making your test run as fast as possible. Have a look at this technical note on speeding up dScope automation for some ideas.
|The dScope script editor debugger doesn't seem to work.
|If, when attempting to use the debugging features of the dScope script editor, you get a message saying "Cannot debug this script. This may be because no debugger is available, or because another script is currently being debugged", the most likely cause is that your computer doesn't have a script debugger component installed.
For 32-bit systems, you can download and install the "Microsoft Script Debugger" from microsoft.com.
For 64-bit systems, download and install the free version of Microsoft Visual Studio Express from http://www.visualstudio.com which contains a script debugger.
|I can't automate dScope from an external application. What's wrong?
|Most often this is because you need to run dScope at least once "as administrator" in order for the software to register itself as an automation server with the system. Just being an administrator is not sufficient, you need to right click on the dScope shortcut and select "run as administrator". You should only need to do this once.
Symptoms of not doing this would include error messages such as "Runtime Error 429: ActiveX Component Can't Create Object" or "A reference to
- dScope III Audio Analyzer - dScope III system home page
- Features and Screenshots - a long list of dScope capabilities and screenshots
- Technical Specifications - detailed technical specifications of the dScope System III
- Software and Manuals - download the latest software, manuals, help files and more
- Architecture Guide - a quick way to find out about how the dScope III works
- Technical glossary - lists acronyms and definitions of some technical terms used on this web site
My problem is not listed here - what should I try next?Contact your local distributor for help: Spectral Measurement distributors
Contact firstname.lastname@example.org for specific problems not found above.
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