Bug? BCD325P2 NXDN issues

[hfxChris]

So I've got the NXDN upgrade, and I've been monitoring a repeater that the local hospital here uses. First I tried programming the frequency in a conventional system with the audio type set to digital only, but it seemed like I was missing bits of the conversations. So I fired up DSD+ next to the scanner, and indeed the scanner seemed to be missing around 50% of the transmissions.

So I tried programming the frequency as a NXDN one frequency trunk. Now here's where it gets interesting. If it's the only enabled system in the scanner, it decodes 100% perfectly, audio is good and clear, it shows a talkgroup ID of 0 which I understand is normal. If I enable another trunked system, say the local P25 public safety system, it completely stops decoding the NXDN system. When the NXDN repeater is active (verified with DSD+) the scanner will actually stop on it, it'll show the 5/5 signal bars, but there will be no audio and no talkgroup shown. As soon as I turn off the P25 system, it'll start decoding audio on the NXDN system.

As a test, I've left it on overnight, with the scanner connected to Proscan for the history logging, the NXDN system enabled, along with the P25 system enabled but with all talkgroups locked out so it won't actually stop on anything. DSD+ running as well all night. The DSD+ log will be full of calls from the NXDN repeater, but the history log in Proscan will be completely empty. As soon as I turn the P25 system off, and it starts decoding the NXDN system again, the Proscan log begins to fill.

Sounds like a bug perhaps?

 

[Ubbe]

The difference is that when it is the only system it will constantly monitor the NXDN data stream but when scanned together with another system it only stays on the NXDN system for the time set in the hold timer. Try setting the hold time longer to 3 sec and see if that helps.

/Ubbe

 

[dsankir]

Good morning,
I have same issue here on my BCD436,if it s turn on P25,it cant decode and work on DMR channels.I ll try to change hold time longer to 3 sec.

 

[buddrousa]

I have not noticed this in my 996p2's or 325p2 but will check with my NX5300 and NX5200. I have noticed that holding on any DIGITAL SIGNAL (P25 DMR NXDN) decodes faster. I think the scanner has to see a frame id code to tell type digital signal it is and scanning it may miss this data on the first pass so as Ubbe stated the hold time will let the scanner look at the signal longer to get the information.

 

[Ubbe]

As per Upmans information the BCD536 needs to monitor a DMR signal for 1,5 sec to be able to extract all neccesary information from it. It will use that 1,5 sec time regardless if the hold time are set to 0 or 1 sec. The decoding routine in 325 are most probably a copy from the 536 and should work in the same way. While parallel listening to a MD380 or TRX-2 I notice that my 536 skips active control channels almost 50% of the time during scan. If I set a 2 sec hold it reduces to 25% and with 3 sec it's down to something like 10%. I have 90% Hytera DMR basestations so that might have an impact if it's only those systems that are problematic, but DMR standards apply to basic TG setup commands so shouldn't really be an issue.

/Ubbe