Welcome to the new FlexRadio Community! Please review the new Community Rules and other important new Community information on the Message Board.
If you are having a problem, please check the Help Center for known solutions.
Need technical support from FlexRadio? It's as simple as Creating a HelpDesk ticket.

How do DAX and CAT work with multiple PCs/Maestros?

Martin AA6EMartin AA6E Member ✭✭
edited January 20 in SmartSDR for Windows
Quick run-down: Maestro, 6500, Win10 PC, all on LAN.  V2 SSDR.  I use Maestro for radio control.  Audio from radio is to Maestro speaker and to DAX on PC (for WSJTX etc).  CAT for WSJTX and Log4OM logger is on the PC.  Audio to radio is usually from the PC (WSJTX, local mic).

This mostly works, but I do not understand how DAX and/or CAT work in the LAN setup, and I can not find much in the documentation.  Specifically, if I have SSDR (DAX/CAT) installed on multiple PCs or Maestros on the LAN, who gets to use DAX/CAT with the radio?  It seems that Maestro and PC can both receive DAX traffic. (The network hawk in me says that PCs and radios should be authenticated to each other or at least locked to specific IP addresses!)  How would you handle a complex multi-Flex, -Maestro, -PC LAN for DAX and CAT traffic?

[I'm guessing that the PC remembers the last Flex radio that the PC's SSDR was attached to, and the PC's DAX / CAT use that remembered radio, even when I do not normally run SSDR on the PC. If so, the doc. should say so.]

Now, my problem: Occasionally (like once in a few hours) the Maestro DAX stream for speaker audio has been stopping.  (I have to restart SSDR for Maestro.)  All this while audio to my PC's WSJTX continues normally.  I can continue my FT8 QSO normally even if the Maestro audio has stopped.  The network seems to be working fine.

Is there a problem with DAX streams going to multiple devices at once? Is my setup wrong somehow?

I suggest a little more detail in the Maestro manual (Sect. 25) about running PC digimodes (WSJTX, fldigi, etc.) and QSO logging on the PC while using Maestro for everything else. A diagram might help.


Completed · Last Updated


  • Mike va3mwMike va3mw Member ✭✭
    edited February 2018

    For multiple PC's you will need to install SSDR on each PC.  DAX and/or CAT will connect to the radio.  So, yes you can do that easily.  I do that today.  You do not need to start SSDR on those other PC's.  

    You can only have 1 Maestro active at any given time.

    If you are loosing contact with the Maestro, if it is via a Wired LAN, then that is unusual (not impossible).

    If via wireless. that happens especially if you are on a 2.4G wifi as it is a very busy band.  Less likely on a 5Ghz Wifi connection.   Full time streaming on Wifi is 'hard' and not all Access Points do a great job of it.  Yes, it is good enough for video as we don't notice it, but harder to be perfect for us who can hear a few packets being dropped.
  • Martin AA6EMartin AA6E Member ✭✭
    edited January 20
    I understand we have to install SSDR to get DAX/CAT functionality.  But if there are multiple radios on my LAN, how does DAX or CAT on any PC know which radio to talk to?  You need a "Chooser" window, and only SSDR gives you a Chooser function AFAIK.

    [I ask because I want to understand how DAX works.  Does each DAX instance start a TCP connection with the radio?  Is it a UDP or broadcast operation?  Etc. I can run WireShark if I need to, but this kind of thing should be in the SSDR docs.]

    That's not my actual problem, since I only have one Flex radio (sigh!).  My problem is understanding why my Maestro DAX connection is stopping, on my (mostly) error-free wired LAN.  The Maestro continues to run normally except for no speaker audio.
  • Martin AA6EMartin AA6E Member ✭✭
    edited January 20
    Mike -

    That's helpful, thanks.  It seems to take care of the problem of multiple radios.  It would be friendlier to have a small DAX/CAT setup app to manage such filters -- and to help users know what they need to do.

    I still don't know when or if it's "legitimate" to take two DAX streams from a single radio simultaneously.

  • Mike va3mwMike va3mw Member ✭✭
    edited February 2018
    Legitimate?  :)  That is a big feature that I just love.   It was designed to do exactly that.

    And, yes a gui would be nice.

  • Eric-KE5DTOEric-KE5DTO Administrator, FlexRadio Employee admin
    edited September 2017

    The FLEX-6x00 series acts as a radio server.  It can support multiple clients all at the same time (caveats apply here -- see *** below).  SmartSDR for Windows, SmartSDR CAT, SmartSDR for iOS, DAX, DDUtil, WriteLog, etc are all separate clients with respect to the radio.  They can be running on the same computer or on different computers.  You can even run the non-GUI clients (clients without a Panadapter or Waterfall like CAT and DAX) on multiple computers at the same time concurrently.

    For now (v2.0 and prior), only a single GUI client (SmartSDR for Windows, SmartSDR for Maestro and SmartSDR for iOS) can be run concurrently.  At some point in the future, we will allow a feature we call "Multi Client" which will allow more than one GUI client to run at the same time.

    In v2.0 and v1.11, SmartSDR for Windows and SmartSDR CAT offer a radio chooser selection that allows the user to choose which radio for that client to connect.  DAX doesn't yet add this capability, but likely will in the future.  To restrict DAX to a particular radio, see the helpdesk article that Mike posted above.

    Prior to v1.11, only SmartSDR had a radio chooser and CAT behaved just like DAX.

    That was probably as clear as mud, but hopefully you can see a progression towards using a radio chooser for the PC clients.

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.