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BCD536HP: BCD536HP delay on DMR beginning of transmission / XPT?

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ecarvalho

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#1
Folks
Questions:

1) What is XPT? This is showing on my local hotspot DV4mini transmission set as DMR conventional.

2) Is it normal to have a 2-3 sec delay receive for DMR? See video comparing a Retevis RT8 and the 536. Notice how the RT8 receives full transmission and the 536 misses a few seconds. Changing the threshold from manual 5 to 7 improve error rate but not the delay.

https://vimeo.com/181054747


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srich10

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#6
I've noticed some delays as well on public release. Haven't done enough sandboxing to figure out the circumstances but I'm testing between my XPR6550 and 436 on a Tier 2 Hytera single freq business repeater.

Best I can tell, it's more prevalent searching the band but I've noticed on and off very minute delays on a programmed system.

Again, I notice this maybe 1 in 50 transmissions so it's not horrible. Could this possibly be slow scanning? Or just the fact that it missed some of the payload of the transmission it picked up on and gets confused until it picks up another full payload to decode completely?
 
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#8
Folks
Questions:

1) What is XPT? This is showing on my local hotspot DV4mini transmission set as DMR conventional.

2) Is it normal to have a 2-3 sec delay receive for DMR? See video comparing a Retevis RT8 and the 536. Notice how the RT8 receives full transmission and the 536 misses a few seconds. Changing the threshold from manual 5 to 7 improve error rate but not the delay.

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Try lowering the Digital Wait Time. See if that makes a difference. I've lowered mine to 0 seconds and I'm hearing a lot more transmissions. My MD-380 and 436/536 are opening at about the same time now.

May not help you're situation, but can't hurt to try.
 

ecarvalho

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#9
Try lowering the Digital Wait Time. See if that makes a difference. I've lowered mine to 0 seconds and I'm hearing a lot more transmissions. My MD-380 and 436/536 are opening at about the same time now.



May not help you're situation, but can't hurt to try.


It's already at zero :(


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UPMan

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#11
Program it as a MotoTRBO Trunk (XPT is handled as a trunked system). All the trunked DMR formats (Connect Plus, Capacity Plus, XPT and DMR III) need to be programmed under trunked to properly scan. Note that I have not personally experienced XPT (and reports were very rare) so I am not ruling out an issue. But, I would not expect it to scan properly as conventional.
 

ecarvalho

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#12
Program it as a MotoTRBO Trunk (XPT is handled as a trunked system). All the trunked DMR formats (Connect Plus, Capacity Plus, XPT and DMR III) need to be programmed under trunked to properly scan. Note that I have not personally experienced XPT (and reports were very rare) so I am not ruling out an issue. But, I would not expect it to scan properly as conventional.


Paul this is odd. Here is why.
The transmitter is sitting on my desk. Is a DV4mini sending a signal over 430.900 Mhz from a DMR ham talk group 3100 US Nationwide into Local Talkgroup 9. This is almost like simplex.
I will try your suggestion and report back!

Note: sometimes it shows "DMR" and others "XPT".





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srich10

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#13
Program it as a MotoTRBO Trunk (XPT is handled as a trunked system). All the trunked DMR formats (Connect Plus, Capacity Plus, XPT and DMR III) need to be programmed under trunked to properly scan. Note that I have not personally experienced XPT (and reports were very rare) so I am not ruling out an issue. But, I would not expect it to scan properly as conventional.
Paul, I would think he would need to program this as a One-Freq DMR rather than XPT. Unless there's some magic sauce somewhere, I don't think a DV4 Mini can do XPT trunking. Kind of begs the question why it shows up as XPT when it should be outputting simplex.
 

ecarvalho

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#14
Paul, I would think he would need to program this as a One-Freq DMR rather than XPT. Unless there's some magic sauce somewhere, I don't think a DV4 Mini can do XPT trunking. Kind of begs the question why it shows up as XPT when it should be outputting simplex.


I tend to agree. DV4mini is a simple transmitter that acts like a hotspot broadcasting ham radio from the internet


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srich10

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#15
I tend to agree. DV4mini is a simple transmitter that acts like a hotspot broadcasting ham radio from the internet


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Right. I've not used a DV4 mini before when I've used DMR, but basic concept is just that; just a simplex transmitter. I believe you can set it up for "repeated" input/output but even then, that would be accomplished through a One-Freq setup on the output channel of the DV4Mini.

It might behoove you to do more testing and see why your 536 is recognizing those transmissions as XPT rather than it showing DMR(for DMR Tier II/One-Freq) or Cap/Con(Tier III trunked DMR)
 

UPMan

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#16
So, this is not through a repeater? In that case, the signal tends to be difficult to resolve (it is a 30mS duty cycle [on/off] carrier). Should be set to the repeater output frequency (which is a continuous carrier) or if you must try simplex, set the modulation to FM, threshold around 5.
 

ecarvalho

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#17
So, this is not through a repeater? In that case, the signal tends to be difficult to resolve (it is a 30mS duty cycle [on/off] carrier). Should be set to the repeater output frequency (which is a continuous carrier) or if you must try simplex, set the modulation to FM, threshold around 5.


I see some improvements on FM but note I have better error rate on Manual 7.

https://vimeo.com/181113197



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cg

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#19
XPT TGID problems?

I was trying to monitor a XPT system tonight with my 536. The talkgroup numbers seem to be strange. Now I can only compare them to what I get from DSDPlus as I don't have access to the system info.

DSDPlus TGIDs
180
182
184
186
190
191
193
194
196

Uniden TGIDs
1048756
1048758
1048762
1048766
2097332
2097334
2097338
2097342
2097343
2097345
2097348

However, if I put the Uniden ones into the DEC part of Windows Calculator in Programmer mode, I can see where there likely is an issue.
For example, the first one, 1048758 in Binary format is
0001 0000 0000 0000 1011 0110
If you only look at the last 8, it is 1011 0110 =182, which is one of the DSDPlus TGIDs. The others all match up as well.
1048756 = 180
1048758 = 182
1048762 = 186
1048766 = 190
2097332 = 180
2097334 = 182
2097338 = 186
2097342 = 190
2097343 = 191
2097345 = 193
2097348 = 196
(the 1048xxx TGs were rare)

I also have several debug files. Seems like it restarted a couple times on it's own but there are several good files. I uploaded the smallest, I have 2 bigger files as well.

chris
 

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EricCottrell

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#20
Hello,

The TGIDs and RIDs are 24 bits in regular conventional DMR. Capacity Plus only has 256 TGIDs (8 bits) and the unused 16 bits are used for other information.

I suspect the upper 4 bits (0001 or 0010) is a LCN for the XPT version of a "Rest Channel" or active LCN.

73 Eric
 
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