Need help finding LCN's for a DMR System

Will001

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I've been trying to monitor a "new" TRBO system in West Columbia that is used by UPS (near Columbia Metro Airport). I'm not sure if the system is ConnectPlus, CapacityPlus or CapacityMax, but I have confirmed the system has 15 frequencies total. The problem I'm having is that I don't know the correct order of the LCN's, so even though I have programmed the system into my BCD996P2, it won't switch to a voice channel to monitor talkgroups. However, if I tune to one of the voice channels manually, I will catch snippets of conversation every now and then

Regarding the system, this is what I know so far:
-It isn't very high-powered; you need to be within a relatively close proximity to KCAE or have a good antenna to receive it
-My 996P2 displays "Net0001: S0001" when I'm sitting on the control channel (and I don't have any idea what it means)
-Color Code appears to be CC0 (according to my 996P2)
-The control channel seems to switch every day; as I'm writing this, the control channel is 936.6500 MHz, whereas yesterday it was 936.1500.
Frequencies:
936.15000 [control channel]
936.22500
936.65000 [control channel]
936.72500
937.15000
937.22500
937.65000
937.72500
938.15000
938.22500
938.65000
938.72500
939.15000
939.65000
939.75000


These are the talkgroups I've found so far:
102
104 Possibly used for ramp ops
110
116 Sounds like a yard channel
117 Possibly the main Air Hub channel
120
121
123
128 Possibly used by the Ground Hub
132
134 Maybe another Air Hub channel, used by management or maintenance
135


Any help with this system would be greatly appreciated!

EDIT: My scanner is now showing "DT3", which I read on another thread means the system is DMR Tier 3 or CapMax.
 
Last edited:

Nchpiboy

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Found this in the RR Wiki:

MOTOTRBO Capacity Max
  • Capacity Max allows voice and data communication up to 15 sites.
  • A system can support up to 250 sites and up to 15 repeaters per site, with up to 3,000 users per site and up to 100 voice talk paths.
  • Capacity Max is fully compliant with the DMR Tier III mode of operation.
  • Powerful management tools give you complete control over the system – all from a single workstation
  • Control channel repeater redundancy
    • You can provision a second control channel per site for ultra-high system availability.



Sorry I can't help with the LCN's
 

Whiskey3JMC

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The x36HP and SDS series scanners have a feature known as LCN finder, this is really the easiest way to determine LCNs. You'd plug in the voice channels you can confirm to be in use into a new MOTOTRBO trunked system, run the LCN finder preferably where the signal is strong & when system activity is at its peak & you'll be set. Unfortunately your 996P2 isn't equipped with this feature. With that said, the OP in this thread developed an LCN calculator. I've never used it so I'm not sure how accurate it is
 

Will001

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The x36HP and SDS series scanners have a feature known as LCN finder, this is really the easiest way to determine LCNs. You'd plug in the voice channels you can confirm to be in use into a new MOTOTRBO trunked system, run the LCN finder preferably where the signal is strong & when system activity is at its peak & you'll be set. Unfortunately your 996P2 isn't equipped with this feature. With that said, the OP in this thread developed an LCN calculator. I've never used it so I'm not sure how accurate it is
Thanks for that link. Is there any way I could use DSD+ to determine the LCN for at least the control channel?
 

cg

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Is there any way I could use DSD+ to determine the LCN for at least the control channel?
Certainly, you can find the LCN for the entire system with DSDPlus. Along with a scanner, a busy system can be mapped very quickly.
There are two ways that LCNs are set up for a system. The first is that a list of frequencies is made and a number is assigned to each, often sequentially. This is then programmed into the radio. So with your list of frequencies LCN setup this way might look like:
936.15000 - 1
936.22500 - 2
936.65000 - 3
etc.
The second way is to use what is known as a band plan. Essentially, you have a base frequency, often the lowest in a band assignment, assigned as LCN 1, then the LCN increases sequentially through the band. So 935.0125 might be LCN 1, 935.025 LCN 2, 935.0375 LCN 3, etc. The frequencies in your system might map to
936.1500 LCN 92
936.2250 LCN 98
936.6500 LCN 132

Often, but certainly not always, you can see patterns and guess at remaining LCNs.
Remember that DSDPlus and Uniden use different ways of counting channels or slots.
 

Will001

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Certainly, you can find the LCN for the entire system with DSDPlus. Along with a scanner, a busy system can be mapped very quickly.
There are two ways that LCNs are set up for a system. The first is that a list of frequencies is made and a number is assigned to each, often sequentially. This is then programmed into the radio. So with your list of frequencies LCN setup this way might look like:
936.15000 - 1
936.22500 - 2
936.65000 - 3
etc.
The second way is to use what is known as a band plan. Essentially, you have a base frequency, often the lowest in a band assignment, assigned as LCN 1, then the LCN increases sequentially through the band. So 935.0125 might be LCN 1, 935.025 LCN 2, 935.0375 LCN 3, etc. The frequencies in your system might map to
936.1500 LCN 92
936.2250 LCN 98
936.6500 LCN 132

Often, but certainly not always, you can see patterns and guess at remaining LCNs.
Remember that DSDPlus and Uniden use different ways of counting channels or slots.
Do you have a tutorial of how this would be done? Sorry, I'm still new to this. Also, should I get DSD Fastlane? Would it make this process easier?
 

cg

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There are LOTS of threads on RR about determining LCN in DMR systems.
You could try setting up the system with the the frequencies in order and the LCN 1, 2, 3, 4, etc. You will have wasted nothing but a few minutes of time. It is not likely that it is going to work but something to try.
For around $50, you can get into the SDR and DSDPlus aspect of the hobby. If your interest is only getting the UPS info, it would be a bit too much to spend the money and then to learn to use DSDPlus.
 

Will001

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What programming software are you using?
=
I'm using SDR# with regular DSD+. I'm sitting on the control channel (today it's 936.1500), and so far the DSD window is filled with the following lines:
+DMR slot1 BS DATA DCC=0 CSBK
+DMR slot2 BS DATA ERR1 DCC=0 CSBK
+DMR slot1 BS DATA DCC=0 CSBK
+DMR slot2 BS DATA DCC=0 CSBK
+DMR slot1 BS DATA DCC=0 CSBK
+DMR slot2 BS DATA DCC=0 CSBK
+DMR slot1 BS DATA DCC=0 CSBK
+DMR slot2 BS DATA DCC=0 CSBK
+DMR slot1 BS DATA DCC=0 CSBK
+DMR CACH ERR slot2 BS DATA DCC=0 CSBK
 

west-pac

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=
I'm using SDR# with regular DSD+. I'm sitting on the control channel (today it's 936.1500), and so far the DSD window is filled with the following lines:
+DMR slot1 BS DATA DCC=0 CSBK
+DMR slot2 BS DATA ERR1 DCC=0 CSBK
+DMR slot1 BS DATA DCC=0 CSBK
+DMR slot2 BS DATA DCC=0 CSBK
+DMR slot1 BS DATA DCC=0 CSBK
+DMR slot2 BS DATA DCC=0 CSBK
+DMR slot1 BS DATA DCC=0 CSBK
+DMR slot2 BS DATA DCC=0 CSBK
+DMR slot1 BS DATA DCC=0 CSBK
+DMR CACH ERR slot2 BS DATA DCC=0 CSBK
The "channel activity" window will show you the LSN number (labeled as channel number). Each LCN has 2 LSN's. The way I get the proper LCN order is: I look at the FCC license, I put all of the FB frequencies into a scanner, then monitor the the Control Channel on DSD+. The Control Channel will have an LSN number next to it on the 'Channel Activity' window. For Example: if the Control Channel is 936.15 and the LSN is 1, then LSN 2 will be 936.15 as well. As system populates LSN 3 you'll receive the digital noise on your scanner from another one of the frequencies on the FCC license. Whichever frequency that is will be LCN 2/LSN 3 & 4. When the activity on the radio system populates LSN 5 you'll hear a 2nd frequency on the scanner come alive with digital noise. THAT frequency is LCN 3/LSN 5/6.... and so on until the rest of the system is populated.

That method will work well when the radio system is busy, and won't take long at all to get the LCN/LSN order. I was monitoring a Con+ site today that was very slow; that site has 9 or 10 frequencies on the license, and is documented in the RRDB to use them all, but the site was only using 3 frequencies/6 LSNs. I presume that was due to the lack of activity today (Saturday), versus during the work-week when there may be more users online.
 

sonm10

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I'm using SDR# with regular DSD+. I'm sitting on the control channel (today it's 936.1500), and so far the DSD window is filled with the following lines:
+DMR slot1 BS DATA DCC=0 CSBK
+DMR slot2 BS DATA ERR1 DCC=0 CSBK
+DMR slot1 BS DATA DCC=0 CSBK
+DMR slot2 BS DATA DCC=0 CSBK
+DMR slot1 BS DATA DCC=0 CSBK
+DMR slot2 BS DATA DCC=0 CSBK
+DMR slot1 BS DATA DCC=0 CSBK
+DMR slot2 BS DATA DCC=0 CSBK
+DMR slot1 BS DATA DCC=0 CSBK
+DMR CACH ERR slot2 BS DATA DCC=0 CSBK


I'm guess it is conventional (non-trunked) DMR and does not require LCNs
 

Will001

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The "channel activity" window will show you the LSN number (labeled as channel number). Each LCN has 2 LSN's. The way I get the proper LCN order is: I look at the FCC license, I put all of the FB frequencies into a scanner, then monitor the the Control Channel on DSD+. The Control Channel will have an LSN number next to it on the 'Channel Activity' window. For Example: if the Control Channel is 936.15 and the LSN is 1, then LSN 2 will be 936.15 as well. As system populates LSN 3 you'll receive the digital noise on your scanner from another one of the frequencies on the FCC license. Whichever frequency that is will be LCN 2/LSN 3 & 4. When the activity on the radio system populates LSN 5 you'll hear a 2nd frequency on the scanner come alive with digital noise. THAT frequency is LCN 3/LSN 5/6.... and so on until the rest of the system is populated.

That method will work well when the radio system is busy, and won't take long at all to get the LCN/LSN order. I was monitoring a Con+ site today that was very slow; that site has 9 or 10 frequencies on the license, and is documented in the RRDB to use them all, but the site was only using 3 frequencies/6 LSNs. I presume that was due to the lack of activity today (Saturday), versus during the work-week when there may be more users online.
Thank you so much for that info, that is the simplest instructions I've seen for this so far! So far, frequency 936.225 is showing as "CH 200", which I'm assuming is the LSN. For some reason, the CC isn't showing a LSN.
 

Randyk4661

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This might help you out. I just did this yesterday. With a spreadsheet you can maybe figure it out.

935.5125 LCN 41 _____ 938.3875 LCN 271
935.5250 LCN 42 _____ 938.4000 LCN 272
935.5375 LCN 43 _____ 938.4125 LCN 273
935.5500 LCN 44 _____ 938.4250 LCN 274
935.5625 LCN 45 _____ 938.4375 LCN 275
935.5750 LCN 46 _____ 938.4500 LCN 276
938.4625 LCN 277
938.4750 LCN 278
938.4875 LCN 279
938.5000 LCN 280
 

west-pac

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Thank you so much for that info, that is the simplest instructions I've seen for this so far! So far, frequency 936.225 is showing as "CH 200", which I'm assuming is the LSN. For some reason, the CC isn't showing a LSN.
What I gave ya will work on a Con+ system. It doesn't sound like it works on a Tier 3 system. The channel activity window will list LSN's starting with "1" on a Con+.
 

cg

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With DSDPlus, until you have the system figured out and info entered into the files, the CC will not show a channel number until there is traffic on the second slot.
Try these channel LSN/LCNs for your system:
Frequency DSD+ Uniden
936.15000 187 94
936.22500 199 100
936.65000 267 134
936.72500 279 140
937.15000 347 174
937.22500 359 180
937.65000 427 214
937.72500 439 220
938.15000 507 254
938.22500 519 260
938.65000 587 294
938.72500 599 300
939.15000 667 334
939.65000 747 374
939.75000 763 382
 

Will001

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Everyone, thank you so much for all the help and information you all have provided me with. So far, my scanner is tracking all talkgroups with no missed traffic. After DSD displays the LSN, all I have to do is put in the number to the lsn/lcn calculator linked in a post above, and so far all the calculated LCN's have been correct!
 
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