This version (27 Nov 2023 10:45) was approved by S Fernandez.The Previously approved version (25 Aug 2023 14:01) is available.Diff

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A2B Bus Analyzer Frequently Asked Questions

FAQs on General Information

f Q: What is the A2B Bus Analyzer?

A: Analog Devices' A2B Bus Analyzer is a robust development tool supporting the design and debug of AD242x/3x based A2B networks. The A2B Bus Analyzer can be configured to act as an active bus emulation tool and/or as a passive bus monitor.

Q: What are the modes can the A2B Bus Analyzer device be used?

A: It can be used as Bus Monitor, Main Node Emulator and Sub Node Emulator.

Q: What features are supported in the A2B Bus Analyzer?

A: The features that are supported in the A2B Bus Analyzer are: Bus monitoring, Audio recording, Event traffic monitoring, node emulation, register access, exporting register details, configuration logging.

Q: Can I use the same analyzer for all A2B families of transceivers (242x, 243x etc.)?

A: Yes, you can use same analyzer for all A2B family of transceivers (AD242x and AD2435W/33W/32W/31W - HDAC/Duraclik connectors), except AD241x and AD2437 (XLR/RJ45 connectors).

Q: How can I order a new Analyzer device?

A: Orders can be placed through the Analog Devices Website A2B Bus Analyzer Evaluation Board | Analog Devices

Q: Where can I get latest A2B Bus Analyzer Software?

A: The latest A2B Bus Analyzer Software is available in

Q: Which Operating Systems are supported by the A2B Bus Analyzer Software?

A: The A2B Bus Analyzer runs on Windows, Linux, and macOS.

Q: Whom should I contact for A2B Bus Analyzer queries?

A: For any A2B Bus Analyzer queries, you can contact to

FAQs on Analyzer Unit and GUI

Q: Where can I get the Quick Start Guide?

A: The Quick Start Guide is available in

Q: Where can I get the A2B Bus Analyzer User Guide?

A: You can get the A2B Bus Analyzer user guide by launching the software and choose Help → User Guide. This opens the PDF which is located in your installation.

Q: Where can I get the licensing guide?

A: The licensing guide is available in

Q: Where can I find out about known functional limitations?

A: The functional limitations and known issues are available in

Q: Do I need to follow any specific sequence for using A2B Analyzer device?

A: Refer to the A2B Bus Analyzer quick start guide to guide you through the basics of the software

Q: How can I get the latest firmware for the device?

A: The current firmware version on the device is shown on the Home screen after connecting to an A2B Bus Analyzer device. If a firmware update is available, click 'Update Firmware' and follow the on-screen instructions to flash the new version to your A2B Bus Analyzer.

Q: Why is the Analyzer GUI not opening?

A: Some instances may already be active or enabled remotely. Check the task manager, then remove any unneeded instances.

Q: I can see my Analyzer Device in the Device Manager but the Analyzer GUI does not show it, what is the problem?

A: There are different reasons why the analyzer GUI may not be able to detect the Analyzer board.

  • The A2>B Analyzer device is being powered via USB which is not supported.
    Please power it with the power supply that was enclosed with the product.
  • The port that the A2>B Analyzer device is already in use by another application in the system but the Analyzer has not been able to detect it.
    By default the GUI uses port 5001. While the UI tries to detect when other applications are using the port, move to a new one and show a user notification, sometimes it is not capable of detecting the problem. When this happens the UI cannot show the Analyzer device in the dropdown. If this happens, you can change the port used by setting the environment variable A2B_ANALYZER_PORT to another value, for example 5002. To do this please refer to how to set up environment variables in your OS of choice.
    To know if your computer is using port 5001 you can run the command netstat -abon and search for 5001 in your results.

Q: How do I export a .dat file from Sigma studio?

A: The sigma studio schematics should be compiled, Right click the target processor, select “Export System config files”. In the Bus Config File (BCF) tab, there is an option to export .dat file, select “Browse”. Click “Generate” and then “Close”.

Q: Is the bus analyzer capable of streaming audio?

A: Yes, there are different ways the analyzer can stream audio. They are * Stream audio from the A2B Bus Analyzer into a file on Host PC * Redirect the Audio to Line Out or S/PDIF Out, * Record using USB Audio 2.0. For this, Windows uses ASIO, Linux uses ALSA, and macOS uses Core Audio. In order to store USB Audio you will require a third party tool. Please refer to the A2BA User Guide → Bus Monitoring → Audio → Audio Stream Input/output configuration on Windows with Reaper for an example setup.

You can get the A2B Bus Analyzer user guide by launching the software and choose Help → User Guide. This opens the PDF which is located in your installation.

Q How do I know if the TDM settings are done correctly in A2B bus analyzer for the node emulation use case?

A: The TDM settings on Analyzer will be done automatically based on the settings done in the A2B Transceiver (in Sigma Studio).

Q: Can I monitor two distinct A2B networks using a single A2B Analyzer?

A: You need two Analyzer Units to monitor events from two independent A2B networks.

Q: My UI was connected to an analyzer board, I disconnected and switched boards and now I cannot connect unless I restart the UI. Is there a bug?

A: The A2B analyzer UI does not update the available board list when a new board is plugged in or removed. It is up to you to press refresh to generate a new list of connected boards. If you try to connect to a board that you unplugged then the UI will fail to connect to it. You should be able to distinguish the boards by their serial number which is displayed on the devices dropdown. The list is automatically generated when you start the UI which is the reason why quitting and restarting works correctly.

Q: When I am using emulator and monitor together I do not see any data in monitor even if I have already started the emulator. Why is this?

A: As documented, the monitor requires a discovery of the network AFTER monitor has been enabled so in the case of sub a link-compile-download from Sigma Studio (or equivalent) is required or in the case of main the apply of the .dat file. Discovering the network before enabling monitor results on no data being displayed.

Q: If I export my event log to a .csv file and open it with Excel the timestamp is incorrect. Does the export contain different data from the event table?

A: The timestamp on the exported file is in the format HH:MM:SS:uS. Excel does not interpret this timestamp correctly and shows the minutes as hours, the seconds as minutes and part of the uS as ms instead. If you open the csv file with a text tool or with MacOS Numbers for example, you can see the correct values. The exported file may contain more information than what can be displayed on the table like full data if the data was too large for the table cells.

Q: How do I run more than one instance of A2B Bus Analyzer UI application on the same machine?

A: Each UI must connect to a separate analyzer hardware, there is no sharing between different instances.

Version 3.2.0 and earlier

A2B Bus Analyzer UI uses two ports: which by default are 5000 and 1880. You need to specify different ports for each instance in order to launch additional copies of the A2B Bus Analyzer UI. Note that environmental variables should be set as individual commands and not concatenated together with &.

cd “C:\Analog Devices\A2B Bus Analyzer”


set A2B_API_PORT=1881

“.\A2B Bus Analyzer.exe”


set A2B_API_PORT=1882

“.\A2B Bus Analyzer.exe”


set A2B_API_PORT=1883

“.\A2B Bus Analyzer.exe” …

Version 3.3.0 and later

The UI identifies that another instance of the analyzer is being run and tries the next port. The UI displays a warning message with the new port. 

The UI tries a maximum of 5 ports after the initial one (5001 or the one specified in the environment variable A2B_ANALYZER_PORT). If you require more than 5 UIs at the same time set up environment variables defining ports for all those instances.

Q: In version 3.2.0 and later, if I have enabled USB Out and then I enable File Out I can see a glitch in my USB Out, why is this?

A: From version 3.2.0, File Out captures audio directly from the USB audio device rather than the USB communication device. When File Out is started, any streams that were already sinking on USB need to be stopped so that the USB route can be restarted with the additional streams that were requested for File Out. Once File Out is started, you cannot alter the output of the USB channels (the UI disables USB controls and the SDK will return A2BA_SDK_ROUTE_IN_USE). When File Out is stopped the original USB route is reinstated.

Q: Why is the dat generated with File Out in version 3.1.0 and in 3.2.0 different?

A: File Out in version 3.1.0 recorded audio as floating point, from version 3.2.0 it is recorded as signed 32 bit integer.

Q: I have a multi-threaded application, can I connect to my device from one thread and disconnect from another one?

A: On Windows, the COM library is initialized as apartment-threaded during a2ba_sdk_device_connect and then uninitialized in a2ba_sdk_device_disconnect, therefore it is required that a2ba_sdk_device_connect and a2ba_sdk_device_disconnect or a2ba_sdk_device_reset (only if the device is connected) are called from the same thread.

Q: Why do i not see streams when .DAT file is exported with 32 streams configured?

A: .DAT file export from SigmaStudio/SigmaStudio+ is incorrect when 32 streams are configured, as the slot registers are not correctly updated. Update the slot registers manually in SigmaStudio/SigmaStudio+ and then export .DAT file to work with 32 streams.

Q: I can no longer connect to the UI/SDK after updating my firmware from 3.1.x. Is my analyzer bricked?

A: In 3.2.x the A2B Bus Analyzer Firmware started to support standalone mode. This means that the position of the standalone switch, which was ignored before, is really important. When the switch is up (standalone enabled) the device can no longer connect via USB and therefore it looks like it is bricked. If you turn standalone off then the UI and SDK should be able to connect in a similar manner as in 3.1.0 and earlier.

Q: I am not able to save audio file using 'File Out' option, why am I getting an error?

A: Please ensure you have write permissions to save the audio file and note that File Out cannot be used from a Remote Desktop session on Windows.

When attempting to use File Out from Remote Desktop on Windows, the USB Audio device is not present in Device Manager and is therefor not available to record audio from. From the SDK, the a2ba_sdk_monitor_audio_file_out_start and a2ba_sdk_emulator_audio_file_out_start APIs will return A2BA_SDK_FEATURE_INACTIVE. From the UI, enabling File Out shows an error message.

In order to get file out to work correctly you must set the  Remote Audio Settings in the Local Resources tab in the Remote Desktop Connection options to “Play on remote computer” before connecting to the remote machine. For more detailed steps see “Bus Monitoring > Audio > Audio Traffic and Controls > Recording Audio to File” in the User Guide.

Refer to Known Issues number 2390: File Out in version 3.2.0 of the A2B Bus Analyzer does not work in non-English language devices, please update to 3.3.0.

Q: How do I ensure that the firmware is operating as intended?

A: Please refer below image.

The Analyzer board has two LEDs, “Power”, which should always be green when the board is powered and “Status”. When the firmware is operating correctly the Status LED should be illuminated green as shown by the bottom A2B Bus Analyzer in the above image.

If the “Status” LED is not green and you are using Windows then please check if the A2B Bus Analyzer is getting enumerated in the Ports (COM & LPT) section of Device Manager. Check if the Analyzer USB port A2B Bus Analyzer is getting enumerated in the Ports (COM & LPT) section of Device Manager on Windows.

Q: What is the maximum size of audio file that can be saved using the A2B Bus Analyzer?

A: The maximum size of a WAV file is approximately 4GB. Should you require a larger file size consider saving using a “.raw” file extension which has no limit, it will save the audio as raw signed 32 bit integer PCM data.

Q: The status LED is always red and the A2B Bus Analyzer UI and SDK cannot discover the device?

A: Version 3.2 and later of the firmware supports standalone mode. While the standalone mode switch was ignored in the past, if standalone is enabled (switch up), the firmware now disables USB and therefore the UI/SDK cannot connect to it. Please disable the standalone (switch down) on the emulator side of the A2B Bus Analyzer.

Q: What are the different recording options available and how many channels can be recorded?

A: There are two options to record a audio file

  1. File Out
  2. USB Out

A2B Bus Analyzer supports saving a maximum of 32 audio streams per session.

With the USB output, we can capture and record network audio on the host computer. Various third-party software applications can be used, e.g. Audacity or REAPER. Both applications are available for Windows, Mac, and Linux.

Refer to the A2B_Analyzer_User_Guide for more information.

Q: What are the different audio sources available on the A2B Bus Analyzer?

A: There are four methods to provide input to the Analyzer

  1. Line In
  2. S/PDIF In
  3. File In
  4. USB In

Various test tones can also be generated to provide controlled and predictable signals in testing and demonstrations.

The A2B Bus Analyzer Application supports three different test tones:

  1. Sine wave
  2. White noise
  3. Pink noise

Refer to the section 'Source Audio—Input Controls' in 'A2B_Analyzer_User_Guide' for more information.

Q: Why is there a power mismatch error when I am emulating AD2428?

A: The issue is due to incorrect export in the .dat file from SigmaStudio for AD2428 devices on SS v4.6 and A2B DLL v19.9.0. But this is corrected in A2B DLL v19.10.0.

Q: Is there an ASIO driver for the A2B Bus Analyzer?

A: ASIO driver is required only if we want to use analyzer's USB IN/OUT and FILEOUT features.

Please refer the “Recording audio via USB output” section in analyzer user guide to configure the ASIO driver. You can get the A2B Bus Analyzer user guide by launching the software and choose Help → User Guide

Q: I get an error that tells me to configure the analyzer port environment variable (A2B_ANALYZER_PORT), why?

A: The A2B Bus Analyzer requires a port on your computer for internal communication. If the analyzer detects that this port is used by another application (or another instance of the A2B Bus Analyzer) it tries to move to the next port up to 5 times. If the A2B Bus Analyzer cannot find an available port after this, the analyzer requires that you set up the environment variable A2B_ANALYZER_PORT to another value from which to start looking, for example 5006. To do this please refer to how to set up environment variables in your OS of choice.
To know if your computer is using port 5001 you can run the command netstat -abon and search for 5001 in your results.

To set up an environment variable globally for a windows environment you perform the following steps (windows 10):

- On the windows search look for “Edit environment variables for your account” to make the change just for your account or “Edit the system environment variables” (the latter requires administrator priviledges) - Within the Generate a new Variable by left click onto New

Enter the Variable Name A2B_ANALYZER_PORT and Variable Value for the number you want to start, for example 5006. Confirm the settings with OK.

When you reopen the UI, this will be the first port that the A2B Bus Analyzer tries.

Q: Why there is no audio data using the A2B Bus Analyzer as Monitor? - Part 1 ENDSNIFF

A: To sniff the monitor slots, bus monitor should be enabled by the main node.To enable, please set the below bit in SigmaStudio schematic before discovery (A2B_DATCTL.ENDSNIFF).

Q: Why there is no audio data using the A2B Bus Analyzer as Monitor? - Part 2

A: If no audio data (upstream/downstream) is present between the nodes where the Analyzer is connected for monitoring, then the analyzer will not show any audio traffic.

Example: Assuming the A2B network contains two sub nodes where the audio stream is configured only between sub0 & sub1 and if the Analyzer(monitor) is connected between main node & sub0 then the analyzer software will not show any audio traffic.

Before starting the discovery, ensure that the “start capturing” button is enabled in the analyzer UI. Please follow the following steps to enable bus monitoring:

* Activate bus monitoring by sliding the Enable Switch * Click Play to start capturing audio and event traffic on the bus.
   Note: Event and Audio Traffic area will remain blank until the network host initiates A2B discovery. * Switch to the A2B network host program (e.g., SigmaStudio, Head-unit software) and initiate discovery process. * With network discovery initiated on the host, the A2B Bus Analyzer application will begin capturing event and audio traffic.

You can also enable monitoring of the network, which is already discovered, refer the “Enable monitoring of network already discovered” section in the analyzer user guide, which is available at Help → User Guide. This opens the PDF which is located in your installation.

Note: When you use the Analyzr as a only monitor, removing the power supply to the analyzer will stop the monitoring but keep the A2B Network alive.

Q: Does the loopback feature of the Analyzer support routing a generated tone through an external development board?

A: The loopback feature of the Analyzer doesn't support routing the sine tone to external board. It is an internal loopback feature only.

Below is the example for performing external Loopback,

Consider A2B Network with 1Main Node (Analyzer) and 1Sub node (Sub0)

A2B Analyzer (Main Node) → Generate Sine Tone → Send Sine Tone down stream using stream configuration → Connect Line-Out of Sub0 to Line-In (External Loop Back) → Send the processed Sine Tone to the Main Node using stream configuration.

Q: How do I access the Analyzer on a remote PC through remote desktop? Can I still use File Out?

A: The default settings for a remote desktop session restrict access to audio input/output devices. By changing the settings of the remote desktop session, the Analyzer should be listed in the device manager.

Follow Below steps:

  • Open Remote Desktop Connection
  • Before connecting, click “Show Options.”
  • Click the “Local Resources” tab.
  • In “Remote audio”, click “Settings…” to “Configure remote audio settings.”
  • Then in the “Remote audio playback” section, select “Play on remote computer” (see image below)

  • Click OK and connect to the remote desktop.

Q: Why is the A2B Bus Analyzer not being detected on the host PC?

A: Ensure that standalone mode is disabled by having the Standalone switch down and reload the list of devices in the UI.

Make sure that the analyzer is connected via its USB port to the PC and ensure that the analyzer is powered with a power supply, not via USB.

If you are on windows, check that the A2B Bus Analyzer is getting enumerated in the device manager.

Press the refresh button to show the available analyzer devices connected to the PC.

Select the analyzer device from drop down and press the power button to connect.

If the problems still persist, please launching the Analyzer software from the command line and send us any errors that may appear on the console when you are trying to connect to the device. The analyzer is by default at:

 "C:\Analog Devices\A2B Bus Analyzer\A2B Bus Analyzer.exe"

FAQs on License

Q: What can I do if I am connected to VPN and my license activation is failing?

A: Under certain rare circumstances the license activation mechanism may fail if the computer is connected to a VPN. In case of problems you should disconnect their VPN. If you are still having issues after that, please get in touch with

Q: I re-flashed my analyzer board and now the tools report that I do not have a license. What can I do?

A: Re-flashing the board removes the license information which was stored at the time of license activation. You should have an email from the activation time that contains both your license key and the validation code. You can use that data again on the same board by utilizing the “Offline activation” feature. If you no longer have your validation code, please request the validation code again from the support team at making sure that you inform them of your device's Hardware Serial Number.

Q: In how many computers can I use an analyzer with the same license?

A: The A2B Bus Analyzer license is related to the A2B Bus Analyzer board and not to the tools or computers. This means that once a license is linked with the specific board, any number of computers (Windows/MacOS/Linux) can use it, there are no limitations.

Q: Where should i put Activation key for “offline” activation option?

A: Please refer to our licensing guide .

FAQs on User Accessible SDK (UASDK)

Q: What is the SDK?

A: The SDK (Software Development Kit) is a set of APIs which provide programmers with a C and Python interface to directly access the A2B Bus Analyzer programmatically without using the UI. This means that the SDK allows users to set up automated testing where control via a GUI is not practical. For some APIs the SDK provides more control than the UI. Please refer to the html documentation for more details on each API. This is located in your exported SDK folder at uasdk/C/docs or uasdk/python/docs. You can also launch the API documentation from the UI on version 3.4.0 or later from the Sdk menu.

Q: Where can I get the UASDK?

A: The UASDK comes bundled as part of the A2B Bus Analyzer GUI software and must be exported to your computer before it can be used.
To export your SDK:

In release 3.4.0 or later: In Menu Sdk → Export User-Accessible SDK… from the application's menu bar.

In release 3.3.0 or earlier: In Menu Help → Export User-Accessible SDK… from the application's menu bar.

This generates a self-contained uasdk folder which contains the SDK itself as well as examples and API documentation.

Q: What is the functionality supported by UASDK?

A: The SDK contains C/C++ and Python interfaces to run certain A2B Bus Analyzer commands like connect to a device and get audio levels. The SDK supports both bus monitor and node emulator. For detailed information about the APIs supported see the HTML documentation in your exported SDK folder at uasdk/C/docs or uasdk/python/docs. You can also launch the API documentation from the UI on version 3.4.0 or later from the Sdk menu.

The SDK also contains a set of examples to demonstrate basic functionality. You can refer to the SDK user guide to build and run the examples. The SDK User Guide can be found as PDF in the exported SDK. You can also launch the PDF from the UI on version 3.4.0 or later from the Sdk menu. Finally it can also be found at SDK User Guide.

Q: Where can I get the UASDK User guide?

A: From release 3.4.0 there is a dedicated Sdk menu in the A2B Bus Analyzer UI. Please choose Sdk→SDK User Guide. In all versions you can access the SDK user guide in your exported SDK in the folder uasdk. You can also get the SDK user guide at SDK User Guide in this wiki.

Q: Which version of python is supported by the SDK?

A: The User-Accessible SDK Python Wheel is now compatible with Python version 3.8 and version 3.10.

Q: Can a device be used from the UI and the SDK at the same time?

A: The shared libraries used by the SDK and the UI are completely separate and they do not interact. This means that when trying to use the same device, both the UI and the SDK try to use the same USB which results in a failure.

Q: Which APIs can be used for selecting Stream Id and starting a tone with that Stream Id?

A: You can use API a2ba_sdk_emulator_audio_info() for requesting the audio info (stream Info) from the emulator and a2ba_sdk_emulator_tone_start (streamId, pToneCtlInfo) for starting the tone where you can pass the streamID as a parameter. From release 3.4.0 you can also use a2ba_sdk_emulator_tone_ex_start to be able to provide multiple streams.

For more details, you can refer to the SDK API documentation in C/C++ or Python. You can access the documentation in your exported SDK in the uasdk folder or from the UI in the Sdk menu. The SDK also contains a file out example in C++ and python which shows how to configure a test tone.

Q: Where can I get the A2B SDK DLL to use A2B Analyzer with LabVIEW platform?

A: Refer to the following link for calling DLL from LabVIEW application. Call a Dynamic Link Library (DLL) from LabVIEW (NI website)

a2ba_sdk.dll can be found in the path: uasdk\C\lib

To export your SDK

In release 3.4.0 or later: In Menu Sdk → Export User-Accessible SDK… from the application's menu bar.

In release 3.3.0 or earlier: In Menu Help → Export User-Accessible SDK… from the application's menu bar.

Q: is it possible to send mailbox command from A2B Bus Analyzer itself without using the SDK (C++ or Python)?

A: It is possible to send mailbox command from the UI in version 3.4.0 or later. For all versions is is possible to do it in C++/Python.

FAQs on Standalone Mode

Q: Is there a limitation on how much data can be captured during Standalone Mode?

A: There is no restriction on the duration of the standalone mode that can be captured as long as there is storage space left in the SD card. However a maximum of only 8 audio slots can be captured. You can refer to the user guide Standalone mode section (8.5) for more details. The user guide is in PDF form in your installation.

Q: The Standalone session playback doesn't show levels for audio slots. Why?

A: Audio is captured only for a trigger window during the Standalone mode. For successful audio capture, make sure of the following

  • The network is discovered
  • ENDSNIFF bit of DATCL register is written by the Main Node
  • The trigger Switch is pressed
  • The maximum number of triggers has not exceeded the count of 25

You can refer user guide Section “Data capture during standalone mode” for more details.

FAQs on Advanced Use cases

Q: How can I specify which Windows audio driver is used to save audio to a file? How can I capture all 32 bits?

A: The A2B Bus analyzer uses the PortAudio library to record from USB to a file. PortAudio supports different Windows drivers each of which drivers has different characteristics. While the A2B Bus Analyzer by default uses the default driver (commonly MME), you can define environment variables to select the driver most appropriate for your use.

See below table for a description of the host APIs commonly available on Windows.

Host API Name PortAudio Host API ID Bits captured out of 32
MME 2 16 Usually the default Host API used. It truncates audio to 16 bits and pads the other 16 bits with zeros. Monitor, Emulator and other applications may use the device to record audio at the same time.
DirectSound 1 16 Truncates audio to 16 bits and pads the other 16 bits with zeros. Monitor, Emulator and other applications may use the device to record audio at the same time.
WASAPI 13 24 Bit exactness appears to vary between 24 and 32 bits. Performance is unreliable and Monitor, Emulator and other applications may interfere with one another.
WDM-KS 11 32 Records all 32 bits but may only record from one of Emulator, Monitor or another application at a time. 
When this driver is used PortAudio cannot differentiate between Analyzers so only one should be plugged in. 
As well as setting A2BA_HOST_API, this driver requires the environment variable A2BA_FILE_OUT_DEVICE which may vary between Windows machines. Please get in touch with for help with what to set A2BA_FILE_OUT_DEVICE to.
resources/tools-software/a2b-bus-analyzer/faq.txt · Last modified: 16 Nov 2023 18:50 by S Fernandez