Having wasted a week in Duck monitoring VIPER, I've now put DPS system into my Uniden for my next visit. I'm perplexed by one thing, though. The TGIDs sometimes increment by 1 rather than by 16 (or 32), and there are several ending in odd numbers in the listings we have up. Is it a Motorola Type II system, or should I be building some other sort of system? Thanks for any and all direction.
Dare TRS TGIDs
- Thread starter rpgallagher
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dare
So were there any traffic on VIPER or just there system.
So were there any traffic on VIPER or just there system.
They could have been using status bits at the end of Talk Groups. Here are what is added to the end of a Talk Group. Hope this helps.
ID+0 Normal Talkgroup
ID+1 All Talkgroup
ID+2 Emergency
ID+3 Talkgroup patch to another
ID+4 Emergency Patch
ID+5 Emergency multi-group
ID+6 Not assigned
ID+7 Multi-select (initiated by dispatcher)
ID+8 DES Encryption talkgroup
ID+9 DES All Talkgroup
ID+10 DES Emergency
ID+11 DES Talkgroup patch
ID+12 DES Emergency Patch
ID+13 DES Emergency multi-group
ID+14 Not assigned
ID+15 Multi-select DES TG
Yep. Greg has it correct. You will see the SHP use Multi-Selects (base ID+7) a lot for dispatching to multiple districts. And Patches (base ID+3) are also very common.
Marshall KE4ZNR
jeffmulter
Member
To add to the original post from RPGallagher, Viper is a Motorola type II mixed mode ( analog and digital modulated voice talkgroups ) system. That will change in the future over the next couple of years, although the Raleigh / Wake simulcast sites will likely go sooner.
The Dare County system is a Motorola P25 system. The two major distinctions for a hobbyist listening to this system, compared to a Motorola type II system, are that ALL voice talkgroups will employ P25 digital modulation, and the rate of the control channel data is 9600 baud - rather than 3600 baud for a type II system.
So, RPGallagher, you need to program the Dare Co P25 sites as a P25 system. The particular system type will depend on which model of scanner you're using, and what software you program with.
Greg provided a list of status bit variations above. Their impact on scanner listeners is only applicable to Motorola type II systems. Some of the variations can be applied to other uses, but note that there are 16 variations in total ... the talkgroup in its original mode, plus 15 alterations of how the talkgroup can operate.
Those status bit variations are why you see talkgroups, when displayed in the decimal format, spaced 16 digits apart (some systems space them 32 digits apart, which leaves slots open for future use).
When you progress to a Motorola P25 system, a different method is used to pass talkgroup variations to the radios and dispatch consoles. Subsequently, P25 system talkgroups tend to be numbered consecutively, with blocks of consecutive talkgroups being assigned to the same user / agency.
Each of those variations to the original talkgroup will change the decimal I-D hobbyists normally use to identify a talkgroup. Most Uniden scanners nowadays allow users to choose whether they want the scanner to recognize or disregard any status bit variations on a Motorola trunked system.
So, if you're listening to talkgroup 12088, and another talkgroup is patched to it, the I-D or the original talkgroup will change to 12091. If dispatch employs multi-select, 12088 will change to 12095.
If your status bit variation setting for the system is set incorrectly, you will not hear either talkgroup in the above example. There are occasions when you may want your scanner to filter out variations to status bits, but 99% of hobbyists probably set the status bit variation setting to disregard variations.
( I'm not sure if the status bit setting feature on Uniden scanners would have any impact on filtering P25 system talkgroups operating in patched or multi-select mode. Any input would be appreciated. - Jeff )
The Dare County system is a Motorola P25 system. The two major distinctions for a hobbyist listening to this system, compared to a Motorola type II system, are that ALL voice talkgroups will employ P25 digital modulation, and the rate of the control channel data is 9600 baud - rather than 3600 baud for a type II system.
So, RPGallagher, you need to program the Dare Co P25 sites as a P25 system. The particular system type will depend on which model of scanner you're using, and what software you program with.
Greg provided a list of status bit variations above. Their impact on scanner listeners is only applicable to Motorola type II systems. Some of the variations can be applied to other uses, but note that there are 16 variations in total ... the talkgroup in its original mode, plus 15 alterations of how the talkgroup can operate.
Those status bit variations are why you see talkgroups, when displayed in the decimal format, spaced 16 digits apart (some systems space them 32 digits apart, which leaves slots open for future use).
When you progress to a Motorola P25 system, a different method is used to pass talkgroup variations to the radios and dispatch consoles. Subsequently, P25 system talkgroups tend to be numbered consecutively, with blocks of consecutive talkgroups being assigned to the same user / agency.
Each of those variations to the original talkgroup will change the decimal I-D hobbyists normally use to identify a talkgroup. Most Uniden scanners nowadays allow users to choose whether they want the scanner to recognize or disregard any status bit variations on a Motorola trunked system.
So, if you're listening to talkgroup 12088, and another talkgroup is patched to it, the I-D or the original talkgroup will change to 12091. If dispatch employs multi-select, 12088 will change to 12095.
If your status bit variation setting for the system is set incorrectly, you will not hear either talkgroup in the above example. There are occasions when you may want your scanner to filter out variations to status bits, but 99% of hobbyists probably set the status bit variation setting to disregard variations.
( I'm not sure if the status bit setting feature on Uniden scanners would have any impact on filtering P25 system talkgroups operating in patched or multi-select mode. Any input would be appreciated. - Jeff )
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Say that again Jeff, no just kidding very well put.
jeffmulter
Member
My writing is sometimes like Locution ... it looks okay to me when I type it, but makes no sense at all when I hit the "send" key.
Old age and continuous lack of sleep really do a number on the mind.
Old age and continuous lack of sleep really do a number on the mind.
Thanks, Jeff. I use Butel's ARC396 app to drive my Unident BCT-396D. I'll need to go back in an check for a P25 system option. I don't remember seeing that choice among the types available when creating systems, before, and maybe I've run up against something different between the 396T and the 396XT. I've been wondering what they were.
I appreciate the information on the different TGID assignment plans for Mot Type II and P25. I was wondering because, as noted, a lot of VIPER traffic is digital (all of Orange County, where I am, for example). The base TGIDs follow the Mot Type II pattern, however, as does Durham, which has several digital groups now. The 396 simply displays "P25" next to the frequency in use off the tower I'm catching, and life is good. That was what perplexed me about the TGIDs listed in the database for Dare.
I appreciate the information on the different TGID assignment plans for Mot Type II and P25. I was wondering because, as noted, a lot of VIPER traffic is digital (all of Orange County, where I am, for example). The base TGIDs follow the Mot Type II pattern, however, as does Durham, which has several digital groups now. The 396 simply displays "P25" next to the frequency in use off the tower I'm catching, and life is good. That was what perplexed me about the TGIDs listed in the database for Dare.
Part of the confusion lies in the fact I made a mistake in this thread. I totally spaced out and forgot Dare Co's system is Pure 25 (9600bps Control Channel). Mea Culpa and thanks to Jeff for catching that.
rpgallagher--it is very easy to get confused with the term "P25" being thrown around alot and being applied in misleading ways.
It is actually incorrect to say that Durham & VIPER have "P25" talkgroups. What should be said is that Durham & VIPER have digital & analog voice talkgroups with a 3600bps CC.
The term P25 should be only reserved (IMHO) for systems like Dare and like Char/Mecks new system that have a 9600bps CC (which means only digital voice talkgroups). If the system has a 3600bps CC then it is NOT a P25 system. It can be an analog only system or a mixed mode system (digital & analog voice talkgroups) but it is NOT a P25 system.
Of course Mixed Mode systems like VIPER can be upgraded to P25 status with a dedicated 9600bps CC. And that is happening for both VIPER and Durham. It takes time (and $$money$$) though to migrate all of the legacy analog voice users to digital voice talkgroups.
Hopefully this helps answer some questions and thanks again to Jeff for helping to clear up some confusion.
Happy Monitoring
Marshall KE4ZNR
rpgallagher--it is very easy to get confused with the term "P25" being thrown around alot and being applied in misleading ways.
It is actually incorrect to say that Durham & VIPER have "P25" talkgroups. What should be said is that Durham & VIPER have digital & analog voice talkgroups with a 3600bps CC.
The term P25 should be only reserved (IMHO) for systems like Dare and like Char/Mecks new system that have a 9600bps CC (which means only digital voice talkgroups). If the system has a 3600bps CC then it is NOT a P25 system. It can be an analog only system or a mixed mode system (digital & analog voice talkgroups) but it is NOT a P25 system.
Of course Mixed Mode systems like VIPER can be upgraded to P25 status with a dedicated 9600bps CC. And that is happening for both VIPER and Durham. It takes time (and $$money$$) though to migrate all of the legacy analog voice users to digital voice talkgroups.
Hopefully this helps answer some questions and thanks again to Jeff for helping to clear up some confusion.
Happy Monitoring
Marshall KE4ZNR
And no help keeping proper distinctions when Uniden is using "P25" to mean "digital" in the screen display. If/when the $$ comes through, will we all need to change the system type on scanner systems that use VIPER? And how, if at all, does switching to pure P25 correlate with rebanding? I noted in the ARC396 application that it says to use "Motorola Type II Custom" for rebanded systems. And since I now know (having scrolled down into new trerritory!) that "Motorola APCO25" is also a system type....
Thanks Marshall and Jeff both. It's great and straight info like yours that makes it worth every penny and more to support the operation.
Thanks Marshall and Jeff both. It's great and straight info like yours that makes it worth every penny and more to support the operation.
Generally speaking, true P25 systems (9600bps) will create a "dynamic" talk group ID when a talk group is console-patched with another talk group or another voice medium (such as a conventional or interconnect source). For instance, if talk group 12001 is console-patched to talk group 12013, the controller may create dynamic ID 20001 for the period of the patch.
I know that if you have all current firmware upgrades in place for your Pro-106/197 or PSR500/600 scanner, it WILL follow the patch on ALL involved talk group IDs (example, the above call would still be "captured" on 12001, 12013, and 20001) and flash "ptch" in the upper right hand corner of the display. This is important if you are scanning without a group wildcard, because you will not capture 20001.
I have no idea if the Uniden DMA scanners will handle this patch issue the same way.
There is no real way to keep track of/store the dynamic IDs because they may change as patches are broken and created. For instance, the above example patch may be broken and re-established a few hours later but the controller may assign 20002 as the new dynamic ID.
If you are using the modern RS or GRE scanner, make sure you have the most current firmware versions to ensure that you will hear patch calls correctly.
EDIT: This trend MAY be applicable only to Harris P25 systems.
I know that if you have all current firmware upgrades in place for your Pro-106/197 or PSR500/600 scanner, it WILL follow the patch on ALL involved talk group IDs (example, the above call would still be "captured" on 12001, 12013, and 20001) and flash "ptch" in the upper right hand corner of the display. This is important if you are scanning without a group wildcard, because you will not capture 20001.
I have no idea if the Uniden DMA scanners will handle this patch issue the same way.
There is no real way to keep track of/store the dynamic IDs because they may change as patches are broken and created. For instance, the above example patch may be broken and re-established a few hours later but the controller may assign 20002 as the new dynamic ID.
If you are using the modern RS or GRE scanner, make sure you have the most current firmware versions to ensure that you will hear patch calls correctly.
EDIT: This trend MAY be applicable only to Harris P25 systems.
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Webodisk
Silent key.
I have a Pro96com dump from my last trip to dare I will see what the patches look like, some of the patches were showing up as a super group like N & S fire dispatch
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