Control channel and ids sharing

NoUsernam · May 21, 2016

i have some doubts in p25 programmig
In my city i found like 10 control channels on 800 mhz, i asumed that are control channels because my scanner show DAT on the screen, i put them in the same system, my question if i did to put the freqs all in one site or in a differents ones, i ask this because i notice they share some ids
I cant get help from the rr database because im not in northamerica
Thats all, sorry for my english

dougjgray · May 21, 2016

If it is a multi site system, ids can be heard on multiple sites. Most likely each control channel is a different site, so it should work best programming that way

ofd8001 · May 21, 2016

I wouldn't want to say anything definitive without knowing exactly which system the OP is discussing.

That said, it is possible there are 10 control channels, one primary the rest alternates. There is no harm in programming all control channels for a site (as well as those that may not be marked as control channels assuming sufficient memory space).

A scanner typically "deals" with only one active control channel per site, disregarding any others. Also if the scanner is handling which voice channel the communications should be directed to, then I'd figure the Unit ID information is also passed along.

wtp · May 21, 2016

it could be

that the dat means data and could just be water meters or mobile data terminals.
the county next to me has 3 systems for just that.

NoUsernam · May 22, 2016

Thanks for all the responses, this is a great and very helpfull community

ofd8001 said:
I wouldn't want to say anything definitive without knowing exactly which system the OP is discussing.

That said, it is possible there are 10 control channels, one primary the rest alternates. There is no harm in programming all control channels for a site (as well as those that may not be marked as control channels assuming sufficient memory space).

A scanner typically "deals" with only one active control channel per site, disregarding any others. Also if the scanner is handling which voice channel the communications should be directed to, then I'd figure the Unit ID information is also passed along.

Is there any way to know what are the primary control channel and the alternates ones?

NoUsernam · May 22, 2016

wtp said:
that the dat means data and could just be water meters or mobile data terminals.
the county next to me has 3 systems for just that.

Thanks for the info. I don't know that so i supposed that al DAT are the control channels

ofd8001 · May 22, 2016

If you look at an RR database entry, you'll see how they are listed. Attached is an example, for my local area:

Louisville Emergency Communications Network: MetroSafe Trunking System, Multiple, Kentucky - Scanner Frequencies

The frequency listed for a site that is Red and has (c) behind the numbers is the primary control channel.

The frequencies listed for a site that is Blue and has (a) behind the numbers are the alternate control channels.

"Primary" is the one used more often than not and alternates are subject to being used occasionally. There are no hard and fast rules however, system managers are free to do as they wish with regard to control channels. Some systems regularly/routine swap out control channels.

Below is copied from the x36 manual concerning what DAT means along with P25 and LNK (could be different owing to what model scanner you have):

P25 Displays if the channel is receiving digitalized voice in Receiving or Hold modes.
LNK Displays when data is received on a voice channel in Receiving or Hold modes.
DAT Displays when data is received on a control channel in Receiving or Hold modes.

So on a trunked system "DAT" means the scanner is monitoring the control channel listening for channel grants to a talkgroup you have programmed to monitor. If a channel grant occurs for a talkgroup in your scan list, then "DAT" switches to "P25" if it is a P25 system or LNK if non-P25 system.

DickH · May 22, 2016

If it is a Motorola system, there are a maximum of 4 control channels per site; 1 control and 3 alternates. If you look through the RR database you will see some sites with only 2 control channels listed, some with 3 and some with 4.
Running Trunker or any program that analyzes the control channel data might be useful.

NoUsernam · May 23, 2016

ofd8001 said:
P25 Displays if the channel is receiving digitalized voice in Receiving or Hold modes.
LNK Displays when data is received on a voice channel in Receiving or Hold modes.
DAT Displays when data is received on a control channel in Receiving or Hold modes.

So on a trunked system "DAT" means the scanner is monitoring the control channel listening for channel grants to a talkgroup you have programmed to monitor. If a channel grant occurs for a talkgroup in your scan list, then "DAT" switches to "P25" if it is a P25 system or LNK if non-P25 system.

So when LNK display its not a p25 system? Good to know that

NoUsernam · May 23, 2016

DickH said:
Running Trunker or any program that analyzes the control channel data might be useful.

Can freescan do that?

zwc · May 23, 2016

Don't think FreeScan can, but ID TRACKER can.
It's also free, contributions accepted. I was glad to donate because the program is awesome for finding IDs and recording.
LOTS of functionality. You have to let it run for a while so it can collect info from hits.
You'll have fun playing with it for sure.

zwc · May 23, 2016

My understanding is if it says DAT, it's a control channel. Other frequencies with data will display LNK.

I would put each suspected CC in it's own system, then monitor a while and see what's going on.

As far as primary and alt CCs go, only one control channel will be active per site. I program all primary and alternates into a system so I can keep monitoring if and when the system manager decides to rotate the CC transmitter and/or frequency to an alternate.

NoUsernam · May 23, 2016

zwc said:
Don't think FreeScan can, but ID TRACKER can.
It's also free, contributions accepted. I was glad to donate because the program is awesome for finding IDs and recording.
LOTS of functionality. You have to let it run for a while so it can collect info from hits.
You'll have fun playing with it for sure.

I think ID tracker is my option to know more about the system i want to monitor
Should de ID TRACKER work with uniden usb-1 cable ?

zwc · May 24, 2016

Sure. You set up your comms link in ID TRACKER just like any other software. Just set the comport number and speed.

You still need FREESCAN, because ID TRACKER will not upload or download frequencies to or from your scanner. Once you connect your scanner and run ID TRACKER and hit Scan it begins to read through all of your trunked and conventional systems. It creates logs of activities including unit IDs, frequencies in your trunked systems, etc. The longer it runs, the more information on users it can collect. You can click on a unit ID in the continuous log it creates and see which systems it's been registering on etc. You can assign names to unit level IDs. It also has a sophisticated recording system, along with it's own audio player.

It has a simple Scanner Control feature so you can control almost all scanner functions from your computer while the other features are running. It ties up very little CPU.

Nifty program, it was actually made to find TGIDs on both known and unknown systems. It will take you a day or two to get a lot of the features under your belt, but your scanning experience will be enhanced once you have it up and running.

NoUsernam · May 24, 2016

zwc said:
Sure. You set up your comms link in ID TRACKER just like any other software. Just set the comport number and speed.

You still need FREESCAN, because ID TRACKER will not upload or download frequencies to or from your scanner. Once you connect your scanner and run ID TRACKER and hit Scan it begins to read through all of your trunked and conventional systems. It creates logs of activities including unit IDs, frequencies in your trunked systems, etc. The longer it runs, the more information on users it can collect. You can click on a unit ID in the continuous log it creates and see which systems it's been registering on etc. You can assign names to unit level IDs. It also has a sophisticated recording system, along with it's own audio player.

It has a simple Scanner Control feature so you can control almost all scanner functions from your computer while the other features are running. It ties up very little CPU.

Nifty program, it was actually made to find TGIDs on both known and unknown systems. It will take you a day or two to get a lot of the features under your belt, but your scanning experience will be enhanced once you have it up and running.

Thanks for the info i really appreciate your help

Control channel and ids sharing

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