DSDplus stopped following P25 system

[dkcorlfla]

From the Notes.txt in DSDPlus,

Using DSD+ with external signal sources

    DSD+ can be used with external signal sources such as a properly discriminator-tapped receiver
    or SDR software such as SDR#. To use DSD+ with these sources, use the menus in DSD+ to
    select Passive Digital Monitor mode and then to select the audio input device that carries
    the digital audio signal. When running in this mode, DSD+ can be used to monitor conventional
    analog and supported digital signals; DSD+ will not directly support trunk tracking.

To do that with sdr#, you will need virtual audio cable or vb cable. You change sdr# audio output to stream over the cable, and configure DSDPlus to use that cable as its input.

In DSDPlus, you tell it to use Digital Passive Monitor.

View attachment 182418


Then under input, select the cable sdr# is outputting on.

View attachment 182419







First thing is make sure your folder options are set to show file extensions. In Win 10, thats under the View tab.


View attachment 182423








You can run 1 rtl-sdr or 1 Airspy in single receiver mode and it will cover it, no matter how many MHz it is. It will sit on the cc and tune to the active voice call, then return to the cc.

Using DSD+ with supported SDR devices

    DSD+ directly supports trunk tracking (control/rest channel following and voice channel
    following) of NEXEDGE, Capacity Plus, Connect Plus, Tier III and P25 Phase I/II systems
    when coupled with one or two RTL2832U-based DVB-T dongles, Airspys or SDRPlay RSP2s.

    When one device is used for trunk tracking, one copy of DSD+ is used to switch between
    control/rest channel monitoring and voice/data call following. For most system types,
    DSD+ will monitor each voice call until it completes before switching back to the
    rest/control channel. However, on most P25 systems, voice channels carry more system data,
    which allows DSD+ to immediately switch from monitoring a lower priority call
    to a higher priority call.

    A single copy of DSD+ plus a single SDR device can also be used to monitor conventional
    analog and/or digital voice channels.

    When two SDR devices are used, one copy of DSD+ monitors and follows the control/rest channel
    while a second copy follows voice calls. The main benefit of using two devices is fully
    prioritized voice call following on all system types. As noted above, for P25 systems,
    using two devices offers minimal additional benefits over the use of a single device,
    although the ability to capture and log all control channel activity may be of value
    for some users.

Thanks for posting the tip on setting the Windows File Explorer to show the file extensions. I don't use Windows much anymore and had forgotten how to set that. It sure is a lot easier to look for files in a folder when one can see the extension.

Yesterday I played around with some batch files that make starting the DSDplus and SDR++ or FMPA much cleaner. It was also nice to have different log files.

Might still need to tweek them some but here are some examples:

DSDPlus -r1 -fa -i20001 >>1R-log.txt

-fa Auto-detect all protocols above

DSDPlus -r1 -fr -i20001 >>1Rdmr-log.txt

-fr Decode DMR/MotoTRBO

DSDPlus -r1 -f1 -i20001 >>1R851-log.txt
-f1 Decode P25 Phase 1

FMPA -rc -i1 -o20001 -f851.4125

-rc Trunk control/rest channel monitor

 

[cg]

One thing to note when you are setting up batch files is the default. The default option is shown in brackets in the Help file. For example, you do not need to include the -r1 option to have DSDPlus do single receiver decoding. I do find though, if I am making multiple batch files, it can help to include all options, including the defaults, to be able to look and see what I am choosing.

-r1 role is single-receiver control/rest/traffic channel decoder [-r1]
-rc role is dedicated control/rest channel decoder
-rv role is dedicated voice channel decoder
-rp role is passive digital decoder