CDM and Motorola Tone Remote Adapter Channel Issues

[FMROB]

Hello,

Removing any console failures or human intervention, has any one ever experienced a CDM1250 connected to a New Style Motorola Tone Remote Adapter changing channels by itself?

A customer has complained that they will leave the console set to channel 1 (for example) and when the return to the console after a few minutes it will be on a different channel. Additionally, the previous vendor has set the tone remotes up to change through seven channels, and left the rest unprogrammed in the radio. Ocassionally the radio will land on an unprogrammed channel and lock up with the unprogrammed channel tone.

Now my issue is that I have never got the Motorola Branded remotes to change more than seven channels myself, so what I wind up doing is picking the most important channel in the radio to the department and for channels 8-64 just entering that channel in, that way if the remote gets lost at least it will land on a programmed channel.. Does anyone have any other thoughts on this?

Secondly, I have never seen a tone remote change channels on its own. In this case it has been witnessed by another technician that the radio changed channels, so I am confident that it is not someone playing tricks. The only thing that I can think of is sloppy tone remote cables that may be shorting and causing the radio to change channels?

Any thoughts, - Rob

[Bill_G]

It could be the adapter doing what it is told. Are there multiple consoles in parallel, or a single console? Standard multi-freq tone remotes, or full blown dispatch consoles from Moto, Zetron, Orbacom, etc? It could be phone line crosstalk. It could be the output level from the remote(s) are too high, or the input gain to the adapter is too high.

If you have more than one CDM/adapter pair, and only this pair are doing it, and your line levels are correct, I would troubleshoot by substitution.

If you have just this single simple setup, I would suspect the remote first, the adapter second, and the radio last.

Is there any chance there is a logging recorder across the line?

I strongly suspect the input level is set way too high, and the adapter is responding to voice or line noise.

[FMROB]

Bill, did I mention that you are the Man,

Here is what I have, (The system was not installed by me, just called in to start troubleshoot)

1) It is a Avtech console
2) Stand alone two postion console system
3) They are brand new motorola multi freq tone remote adapters ( dont know model ## but they look like gai-tronics crap)
4) No recorder that I am aware of (might be digital through IP system)
5) There are three tone remote//CDM set-ups, all three are having this problem, sparadically.
6) Outposts are mounted on the first floor with a 25 pair copper cable run to the second floor where the radios and tone remote adapters are mounted.

I have not started checking levels yet, but will next week. I have not an idea as to how the levels were set on the system?

It is noteworthy to mention that the console is not yet in operation, it is a quazi new install. This happens when the console is sitting idle. Could it be that a radio is RX'ing and the signal sent down the copper cable is causing cross talk on the other tone remotes??

Also, any thoughts on the # of channels that they can change (more than 7). I always use the CPI TTP216 or Zetron 250 so I can do 15 channels w/o a problem.

Thanks - Rob

[Bill_G]

Oh no - you da man Rob. You da man on the hot seat. (grin)

Hmmm - okay - best guess - (in order of probability) the consoles are randomly spitting out commands, the adapter inputs are set too high, or it's crosstalk on the 25pr cable, but it's not the radios.

Since all three CDM's are doing this, that suggests they are obeying a valid mode change command. It's hard to believe there is the same hardware failure in all three new radios. More likely the adapters. However, Gaitronics stuff tends to be pretty reliable. But, if their inputs are set too high, who knows what could happen.

Since this seems to be happening randomly when a console position is idle, and the system is not operational yet, I'd divide the problem in two. Set all the radios to chan 1 with the consoles, pull the bridge clips between the console and the adapters, and let it sit for a couple days to see if the radios move.

If that proves true (that the radios did change channel), then you get to troubleshoot the CDM's and adapters.

If that proves false (that the radios did not change channel), then reconnect the console lines, and pull the ethernet cable to the gateway for a few days.

If that proves true (radios did change channel), then it's the gateway.

If that proves false (radios did not change channel), then reconnect the gateway eth cable but shutdown the Avtech application. And then call Avtech Tech Support to see if this is a known problem.

edit to add: download Wireshark, and get it running on your laptop. Don't expect to learn it overnight. Put a copy on a thumb drive and transfer it to the Avtech consoles to monitor the traffic between the consoles and the gateways. Try to determine what the command structure looks like for a mode change. Then set Wireshark to capture any mode change commands in the custom filters. Let it run for a few days and look through the logs if the problem occurs.

[FMROB]

BIll, Ok I will start exactly like you said. My thought was that it was either a sloppy interconnect cable OR some sort of level issue.

BTW, any experience with the Moto tone adapter and channel changing more than 7 channels.


Again, thanks you are a true asset to the board.. I would like to think that due to all of my annoying and crazy questions that someone else can use the info to help solve a mystery.

- Rob

[Bill_G]

You should go over the workmanship of the cable between the adapter and the radio as part of your work. Some guys build good cables. Some don't. It would be pretty embarrassing to get far into the repair with no solution only to discover you overlooked a poorly constructed cable.

On multi-freq radios - I try to get people to shy away from those for command radios. One resource - one radio. If they need to cover 16 channels, they'll have 16 resources on the desktop, and 16 radios spread around the region. Especially for critical operations. That does add cost, and if they are trying to shave every dollar out of a project that they can, then more power to them. I'll work with them, but I have no systems with more than two channels in any radio. So no, I have never run into the 7 channel limit on remote adapters.

[alex]

Rob,

I have had two CDM1550 radios hooked up via the Motorola (Gaitronics) TNA200 style termination panels. I can channel steer a total of 16 channels. In order to do the full 16 you need to use all the assignable pins on the CDM, leaving the monitor function to be triggered by the Microphone HUB and some programming in CPS. The console is a MC2500 console.

I did some research before we started this project and determined that CDM1250's will only allow you to channel steer up to 8 channels via 3 pins with the bit values of 1, 2, and 4. All of them off is channel 1, all on is channel 8. (Time to break out our friendly truth table).

The CDM750 will let you channel steer 4 channels.

What we ended up doing was building 16 scan lists for each radio so that depending on what channel you were on, certain things always had priority. We turned off user editable scan lists in the radio (to prevent those with keys to where it was monkeying with the settings) and used auto-scan on some personalities. We then wrote up a 3-4 page document on how everything works and trained people on it.

It's been working great for a number of years in part due to user training (I do like what Bill_G said about one radio per channel you need to monitor) but it can be done if you have somewhat smart users who understand how it works through training and drilling.

-Alex

[FMROB]

Alex,

Can you ellaborate on how you did this? I have tired to use all four pins, Channel steer 0,1,2,3,4 and most it will do is 7? Please tell me its magic.

[FatBoy]

Rob,
could you check what firmware is in the radio? I have had weird CDM operation with consoles/remotes due to low firmware numbers. I would double check this as you are called in to mop up someone else's mess (ie, do not assume they are new...). FatBoy

[alex]

Hey Rob,

http://www.gai-tronics.com/products/man ... 4-010g.pdf is the manual for the ITA2000 (aka TNA200). This is the box we have currently in use for the channel steering.

What I can't remember for the life of me *why* there is a pin 5 that you can use to channel steer. Reading through the manual it looks like it is so you can have the value of 16 (thinking that most people don't get that channel 1 is really 0 (in hex) and channel 16 is really a value of 15 (in hex).

Regardless, the manual shows which lines are the channel steering lines. I would go through and make sure that the lines are pined out properly to match the programming on the radio. This goes back to the original suggestion to check the cable itself and ensure that the pin's are matching to the functions on the termination panel.

Another suggestion is that some console systems (I think Centracom's fall in to this bucket) will only support channel selection of up to 7 channels. This could be the problem that you are having. Double check the console specifications to ensure that it will support all 16 channels. You may also want to listen to see if the console is generating the right frequency tones.

Sadly, I do not know what the pin outs of our cable is. I do remember that i had to go through the manuals and CPS at the dealer and walk him through how it needed to be wired. Once that was done he was good to go.

The manual from Gaitronics is pretty detailed. I would expect the values for the cps pins to be:

Pin #1: 1
Pin #2: 2
Pin #3: 4
Pin #4: 8
Pin #5: 16

Good Luck.

-Alex

[Jim202]

With all that has been said so far on this post, you have some good information to follow.

I will say that the levels used on the control lines are very important. Both the RX level going
back to the console and the levels leaving the consoles. Cross talk between the telco pairs
in a cable can cause all sorts of grief. This is why the phone company yells at any radio
circuit that tries to pump audio over the cable above the normal 0 db limit.

There have also been a good number of threads on here on the topic of how to adjust the
tome remote levels. I like to keep it simple and adjust for the low level idle tone (2175 Hz)
for about a -27 db. This gives you the -10 db that mother M keeps trying to get everyone
to set the high audio tone levels (normal voice) at. The RX level coming out of the radio
with a near full deviated tone should be in the order of a -10 db. You can't miss using these
levels to start with.

The tone remote adapters should decode the low level idle tone down to about a -38 to -40 db
if they are working correctly. This gives you a good 10 db of play for a line that may have issues
over the course of time.

It will take 2 people to set the entire tone remote system up correctly. Generally the dispatcher
can be used as one end while doing the alignment. I also use the 1000 Hz alert tone that is on
most consoles to generate the high level audio for testing levels. You can also use this to see
what the transmitter deviation is set to. Getting the levels wrong can cause the transmitter to
be into audio compression and cause audio distortion on paging tones. The paging audio
levels is a whole different discussion and we don't need to go there on this issue being discussed.

Jim

Hello,

Removing any console failures or human intervention, has any one ever experienced a CDM1250 connected to a New Style Motorola Tone Remote Adapter changing channels by itself?

A customer has complained that they will leave the console set to channel 1 (for example) and when the return to the console after a few minutes it will be on a different channel. Additionally, the previous vendor has set the tone remotes up to change through seven channels, and left the rest unprogrammed in the radio. Ocassionally the radio will land on an unprogrammed channel and lock up with the unprogrammed channel tone.

Now my issue is that I have never got the Motorola Branded remotes to change more than seven channels myself, so what I wind up doing is picking the most important channel in the radio to the department and for channels 8-64 just entering that channel in, that way if the remote gets lost at least it will land on a programmed channel.. Does anyone have any other thoughts on this?

Secondly, I have never seen a tone remote change channels on its own. In this case it has been witnessed by another technician that the radio changed channels, so I am confident that it is not someone playing tricks. The only thing that I can think of is sloppy tone remote cables that may be shorting and causing the radio to change channels?

Any thoughts, - Rob

[KE9GK]

Alex & Rob -

To comment on your previous posts about mode steering all 16 channels with that extra pin #5...YES it can be done. In fact, I have a couple radios set up at a local PD to do just that. The key to this whole thing is the flavor of MOTO radio that you are using and if the console supports all the function tones as stated earlier. The PD has 3 CommandPlus units...and all the function tones are programmable into the console as mode steering commands on a per-resource basis. So far the only mobile radios I have found that will accept steering to all 16 channels are the GM300 series...coupled with the TNA200/ITA2000 adapters. Not very useful for narrowband migration (unless you have the good ones) or Moto support for obvious reasons. I myself have never been able to get a CDM or CM series radio to steer above 8 channels...and they seem to get "lost" quite easily if there is a lot of channel changing....unlike the GM300's....they snap to and lock on their channel permanently within 3 seconds of power up....and there is no changing it if the TRA is powered up...even from the face of the radio. I never thought I'd say this out loud...but...its too bad that the CDM/CM series were not built like the Radius series..they were good little units for this application!

Just my $.02 worth
-D

[wx4cbh]

Just a thought: recently had a system similar to what's described here doing the same thing. Turned out to be the combo of hot levels and a switching power supply in the consoles that was producing noise spikes in EVERYTHING. Every time a certain pattern of noise got into the Gaitronics element, the CDM would change channels at anything between 5 and 30 minutes, and it seemed random at first. I could hear the result of the switching noises on a scanner in the plant control room that is used to monitor plant security, so, as I used a Fluke Scopemeter to look at the I/O and power input on the tone adapter, the truth was revealed. The ol' Scopemeter and clues provided by the cheesy selectivity and power filtering in a scanner saved me from a severe hair pulling.

[wavetar]

I'm not clear if the original poster is saying the remotes themselves are changing channels (ie: the channel displayed in the remote dispay has changed) or if the CDM radio has changed channels according to it's display. Your post indicates it's at the remotes, but a lot of the advice given refers to the CDM, so I'm not sure.

I have seen one instance of the radios randomly changing channels, while the remotes sat happily on their last chosen channel (ie: remotes remained showing "Channel 1" while the radio displays randomly changed to "4", or "8", or whatever). What was happening was the Motorola TRA's & TAIT radios were sitting in an equipment rack, everything powered via common DC supply. Ultimately I found noise on the DC which was apparently causing the TRA's to think they were receiving a command from the remotes, and changing their binary outputs accordingly. Once the TRA's were put on their own DC supply, the problems went away. It's worth noting there was a lot of other equipment in the rack, none of which seemed affected by the noise, including the TAIT radios...only the TRA's

So, depending on whether you're seeing the problem at the remote display, or the radio display, or both, there could be several different answers. I'd suspect dirty power at the remotes if their display is changing & the radios are following...it's basically a one-way street so they shouldn't be affected by anything coming back up the line to cause changing channels. If it's only happening at the radios, I'd suspect the power issue at the TRA's, as they've ben shown to be affected in my past experience.

[FMROB]

Hello all,

The problem was found to be a error in the punch block on one end. The TX anx RX pairs were punched crossed between two different radios AND the levels were ALL way to hot. So I am guessing that a fair amount of crosstalk was occuring. Fixed the punch block, adjusted levels, so far so good, Thank you all for the help.


I agree with the top, provided that you had a console or tone remote that allowed programming for 16 channels (like for example a C200) I still have not got a CDM to do 16 channels???

- Rob

[Bill_G]

I've crossed pairs before. it happens. Good find rob.

[kb4mdz]

Bumping this old thread;

FMROB, I seem to have come across a similar thing. I've got a UHF CDM1250, first I had it on a CPI TTP-1; worked fine. But, I thought I have 16 channels, I want to see if I can use them all; had a Moto L3276 sitting around; wired up a cable, attached it to the radio (only put 4 freqs. in the 1st zone, rest in that zone were blank), and put a 4-freq. CPI TR10 on it. Worked fine initially, changed to first 4 channels no problem. But came back in the office later & the remote was giving the error tone like the radio was on an unprogrammed channel; baaaaaaaaaaaaaaaah.. Back in the equipment room the radio was on an 'unprogrammed' channel, and front panel Channel Up/Down buttons had no effect, so definitely the L3276 had control of the channel select lines. Back to the remote; selected any channel, radio steered & worked properly. Couple hours later, same thing.

Only thing I could think of was I had just pulled it off the used shelf & the levels are/were too hot out of the radio; the one channel I had been monitoring each time has a bunch of users who practically yell into the microphones, and best guess is the distortion generates enough Function Tone to switch to a new channel;

[HumHead]

I have not set up a CDM to channel steer in a long time, and I cannot find the reference material at the moment, but I seem to recall that the input logic is actually BCD, not HEX, hence the need for five pins.

[kb4mdz]

CDM1250 only has 4 pins available; that's why you can only got to 15 channels.

It's kinda weird. I always have to go back to my notes from the previous effort to do a new one.

[FMROB]

You need to populate all channels on the zone selection screen in order to avoid unprogrammed channel. If you are only using 4 channels, duplicate you most important channel. Let's say channel 1 is the most important, program the zone list channel 1, 2, 3, 4, 1, 1, 1, 1, 1, 1, 1 all the way to 16.