CDM1250 interface to a Centracom Gold?

nmfire10 · Post by **nmfire10** » Sat Dec 06, 2003 4:50 am

Two questions, one being dependent on the other.

There is an interface to connect a Centracom Gold Elite right to the control head of a CDM1250, right? Like, no tone remotes or anything. Just hooks right into it?

If this is the case and the console has the dropdown menu for selecting channels, does the Console just display whatever channels are programemd into the CDM or do you have to program it all into the console as well? Like if we want to add channels to the CDM, will they show up on the console as well?

nmfire10 · Post by **nmfire10** » Mon Dec 08, 2003 4:47 am

Anyone? Anyone?

Post by **wavetar** » Mon Dec 08, 2003 4:56 am

Never seen it, although it sounds similar to a set-up that one of the members posted about a few months ago. In his case, it was a Nextel/Telus radio, not a CDM. But it apparently interfaced to the CEB directly, not through a BIM/Tone remote configuration. Sounds like a call to System Support might be in order.

Todd

RKG · Post by **RKG** » Mon Dec 08, 2003 7:10 am

I don't know the answer to your question, but bear in mind that if you used the CCG functually as an extended local control, rather than functionally as a remote, there is a severe length limitation in the connection cabling.

nmfire10 · Post by **nmfire10** » Mon Dec 08, 2003 8:16 am

Console is on the first floor, CDM's are on the roof of this 6 floor building. I seem to remember something about a device the directly controls a CDM with the Centracom Gold. As for radio techs, I left a voice mail last week that has yet to be returned.

Post by **wavetar** » Mon Dec 08, 2003 10:29 am

nmfire10 wrote: As for radio techs, I left a voice mail last week that has yet to be returned.

I assume you mean the techs at system support? If they don't return the call within 24 hours, it generally doesn't get returned at all. You'll need to call them again.

Todd

RKG · Post by **RKG** » Mon Dec 08, 2003 12:00 pm

I wouldn't run an extended local control over 100+ feet of cable.

What you may have in mind is a TRC termination panel for the CDM that gives enhanced control (channel change, scan, etc.). I believe that CPI has such a termination; how (if at all) it might be interfaced with a CCG is something I wouldn't guess at.

nmfire10 · Post by **nmfire10** » Mon Dec 08, 2003 12:34 pm

Maybe I am just on crack about this control thing. We can here the keyup tones and such on the radio that I KNOW are tone remotes. These two CDM's though, I don't hear any tones. I could swear there was a non-tone remote control interface for the CDM's that allowed you to use all 64 channels.

Post by **wavetar** » Mon Dec 08, 2003 2:21 pm

nmfire10 wrote:Maybe I am just on crack about this control thing. We can here the keyup tones and such on the radio that I KNOW are tone remotes. These two CDM's though, I don't hear any tones. I could swear there was a non-tone remote control interface for the CDM's that allowed you to use all 64 channels.

So, you already have the CDM radios controlled through the Centracom, and are just wondering how they are hooked up? Explain what you mean by 'keyup tones'. Is this a tone heard at the console, or over the air? The only 'keyup tones' I'm aware of hearing are talk permit tones for trunking radios, which you'll only hear if the remotes are set-up with 4-wire circuits.

Oh, I found that other thread I was talking about earlier. It's the only alternate way of interfacing a radio to a Central Electronics bank that I'm aware of:

http://batboard.batlabs.com/viewtopic.p ... ight=telus

Todd

nmfire10 · Post by **nmfire10** » Mon Dec 08, 2003 6:16 pm

I mean I hear the tone remote tones. Like, when I push the transmit button, very faint in the speaker or headset, I hear the tone remote tones key up the radio. Also, if I push monitor, you hear the tone remote tones for putting it in and out of monitor. I hear this on 3 different radios, all of which I believe are quantars or other similar Motoroa repeaters.

On the two CDM's, I do not hear any of these tones. That coupled with this strange control system I for some reason think exists, belive they aren't tone controlled.

Alan · Post by **Alan** » Mon Dec 08, 2003 7:27 pm

CDM's have channel steering lines(4 lines of BCD). Are they using these lines (up to 16-channel selection?) to do channel changing?
With channel steering and local control, there are no keying tones.

nmfire10 · Post by **nmfire10** » Mon Dec 08, 2003 7:36 pm

Well, we have a lot more than 4 channels in both of them now.

RKG · Post by **RKG** » Mon Dec 08, 2003 8:12 pm

1. Four lines arranged BCD will get you 16 channels.

2. Whether or not you generate control tones depends on how you signal those lines. If done locally (i.e., by directly taking the lines low), you wouldn't hear anything. If done remotely, then there will be HLGT and function tones that the termination panel on the radio will translate into the relay closures that bring the lines low.

nmfire10 · Post by **nmfire10** » Mon Dec 08, 2003 8:51 pm

[quote="RKG"]1. Four lines arranged BCD will get you 16 channels.

Ok. English translation?

Post by **HumHead** » Mon Dec 08, 2003 10:56 pm

I believe that the channel select lines are straight binary, not BCD. BCD would, by definition, only allow 9 channels on four lines since each four bit word has a maximum value of 1001(BCD). So 16(10) would have to be 00010110(BCD)- Binary 1 + Binary 6.

At any rate...

The CDM series allow for 15 channels to be steered on four lines.

The channel select inout lines on the radio form a binary representation of the channel number that you want to select where, in binary, the lines are:
(CS4) (CS3) (CS2) (CS1)

So, assuming that you set the pins for "active high", and using "1" for high and "0" for low, you would get:
0000 - Radio controls channel selection
0001 - Ch1
0010 - Ch 2
0011 - Ch3
0100 - Ch 4
0101 - Ch 5
0110 - Ch 6
0111 - Ch 7
1000 - Ch 8
1001 - Ch 9
1010 - Ch 10
1011 - Ch 11
1100 - Ch 12
1101 - Ch 13
1110 - Ch 14
1111 - Ch 15

Hope that clears it up a bit.

Post by **alex** » Tue Dec 09, 2003 6:52 am

When you hook up the CDM's to the tone remote (I have not played with local remotes before - wouldn't mind sometime, but haven't...).

You'll need to use all the pins in the rear that you can for the tone selection. If you'd like the monitor function to remain, you have to give up access to 1 channel to use that function tone for monitor. This can be done by making something that uses the RJ45 mic connector to take the radio "off hook", thus, giving you monitor (providing the radio is also programmed correctly). I believe the monitor function is something that is supposed to be required by the FCC for at least the base stations. (I think I posed the question about it and it was discussed here a while ago).

Either way, use the front RJ45 for off hook monitor on the radio - I believe with the GaiTronics tone remotes, a small relay has to be installed for it to work right. I didn't do the work, this was just the end result of telling the MSS this is how it could and needed to be done.

Not pretty - but works.

-Alex

RKG · Post by **RKG** » Tue Dec 09, 2003 2:17 pm

HumHead is 100% correct; my use of BCD was sloppy. Thanks for the correction.

nmfire10 · Post by **nmfire10** » Tue Dec 09, 2003 3:00 pm

Well, you learn something new every day. I never knew that is how those channel steering pins worked. So what does it do if you steer it to a given channel then remove the active high or low from the given pins? Does it just stay there or revert back to where it was before?

Alan · Post by **Alan** » Tue Dec 09, 2003 6:59 pm

The way that the channel steering works is that you must leave the radio on channel 1 (locally on the friont panel of the radio).
The channel steering then "pulls" the radio to the selected channel.
If you pull line 1 active, it will stay on channel 1. If you pull line 2 active it will go to channel 2. If you pull both line 1 and 2 active, it will go to channel 3 and so on.
Releasing all lines the radio will revert back to channel 1.

You must not perform channel steerring when the radio is transmitting. The radio will stop transmitting if you channel steer while transmitting and you must re-key.
You can simutanously channel steer and TX (ie bring both a channel steer line and PTT line low at the same time.

Hope this helps.

nmfire10 · Post by **nmfire10** » Tue Dec 09, 2003 8:37 pm

And what happens if you are on say Channel 34 when you enable the channel steering pins?

Post by **HumHead** » Wed Dec 10, 2003 2:36 pm

I'm not sure which radios Alan is talking about, but the CDMs always steer to the mode indicated by the steering lines, regardless of where they started, and return to that mode when the lines are released.

I got bored today and went into the back of one of our racks and actually verified this.

I pulled the tone remote, set the radio to channel 7 locally, then plugged the remote (currently steered to Ch 1) back in. THe radio went right to Ch 1. When I pulled the plug again, the radio went right back to Ch 7.

I tried it on both 1250s and 1550s, so it at least holds true for that series.

Alan · Post by **Alan** » Fri Dec 12, 2003 6:00 am

Thanks for the correction to my info.
I was going back to GM300/Maxtrac where it is stated in either the tone remote or RSS manual that the radio must start on channel 1. I'm glad it does not apply to the CDM.

Isn't it amazing that you spend 3 or 4 times as much for a MCS2000 and it has almost zero in the way of these functions. No channel steering. No flat audio i/p. No polarity select on emerg input. No disc audio output. No PA mute. No control outputs. and on and on and on...........

The sales guy keeps trying to get our department to buy "HI" tier product, but the do so little. There, thats my rant for the morning. Sorry for going off topic.

nmfire10 · Post by **nmfire10** » Fri Dec 19, 2003 11:40 am

Well, I got my answer from our Radio Service company. The way it is arranged here, we can have a maximum of 14 Channels. There is no monitor function and I'm not sure what happened to 15 and 16. I wish I had a few more, but I guess I can make it work.