Welcome to the FlexRadio Community! Please review the new Community Rules and other important new Community information on the Message Board.
The latest SmartSDR Software:
SmartSDR v4.1.5 | SmartSDR v4.1.5 Release Notes
SmartSDR v3.10.15 | SmartSDR v3.10.15 Release Notes

The latest 4O3A Genius Product Software:
The latest 4O3A Genius Product Software and Firmware
How to Receive Technical Support::
If you are needing assistance with FlexRadio products, please refer to the product documentation or check the Help Center for known solutions. Need technical support from FlexRadio? It's as simple as creating a HelpDesk ticket.

What is format of DAXIQ data?

AB4EJ
AB4EJ Member ✭✭
edited June 2020 in FLEX-6000 Signature Series
When I activate DAXIQ data on a slice, I understand per the wiki that the DAXIQ data is sent via UDP port 4991. However, I have not been able to find a low-level description of the format of the IQ data. Specific questions:
- how many IQ samples are in each buffer sent?
- what format are the IQ samples?  I & Q values, each 32-bit floating point (such as IEEE 754 single precision, or what?
- what is the endianess of the data? Do I have to rotate the bits or something to work with it in fftw?
Sorry if this is answered elsewhere, I have not found it so far.

Answers

  • Dan-N7HQ
    Dan-N7HQ FlexRadio Employee, Community Manager admin
    edited June 2020
    Bill,

    It's streamed in VITA-49 format.  Please see http://wiki.flexradio.com/index.php?title=SmartSDR_Ethernet_API

    Here is an excellent community discussion with FlexRadio engineering about the data within the VITA-49 envelope.
    https://community.flexradio.com/flexradio/topics/iq_stream_from_6700_radio


    73,
    Dan


  • AB4EJ
    AB4EJ Member ✭✭
    edited June 2020
    Dan - I have looked at the wiki article you cited; it does not explain the VITA-49 format, nor does it include a link to an online specification.  I have done quite a bit of online searching for the spec, but all I have found so far is general discussions of it that don't get into the details; could anyone point me to the specification itself?

    A second question: using SmartSDR, I activate a DAXIQ stream both in the panadapter slice and also in DAX; then I look for UDP traffic on port 4991. Is this right? Because (using tcpdump or windump) it looks like all the same traffic is on that port with or without a DAXIQ stream activated. Does DAX wait for a connect/bind command or something before it starts streaming on port 4991?
  • Geoff AB6BT
    Geoff AB6BT Member ✭✭✭
    edited June 2020
    The protocol is in here (Page 9):
    https://www.redrapids.com/images/documents/REF-004-002-R02.pdf

    Does that help?
  • AB4EJ
    AB4EJ Member ✭✭
    edited June 2020
    Geoff:  Thanks, it does help!  Quick question: have you run across an already coded data structure (C, C++ or C#) for the Signal Data Packet?  I can code it, but this could save some time...
  • Geoff AB6BT
    Geoff AB6BT Member ✭✭✭
    edited June 2020
    Hi Bill, no sorry I don't.
  • Dan-N7HQ
    Dan-N7HQ FlexRadio Employee, Community Manager admin
    edited June 2020
    The full specification is available from the VSO (Vita Standards Org) 

    https://www.vita.com/Standards

Leave a Comment

Rich Text Editor. To edit a paragraph's style, hit tab to get to the paragraph menu. From there you will be able to pick one style. Nothing defaults to paragraph. An inline formatting menu will show up when you select text. Hit tab to get into that menu. Some elements, such as rich link embeds, images, loading indicators, and error messages may get inserted into the editor. You may navigate to these using the arrow keys inside of the editor and delete them with the delete or backspace key.

Comment As ...

Categories