Transmitter steering with an astrotac and/or DIU3000

[nmfire10]

Lets say I have a DIU3000 and an Astrotac comparator. I have a console that can send a multitude of keying tones to the DIU and can do contact closures as well (not a Motorola console). This is conventional astro. Now I have two Quantar transmitter sites connected to the DIU by phone lines. I need to be able to steer the dispatcher and the comparator to one or the other. I don't care how, it just needs to work. Ideally, I would like to use keying tones to tell the DIU or comparator where to steer. But at this point I'm open to any and all ideas.

Second order of business. I need to be able to switch each of those Quantars from Station to Repeat with DTMF over the air. What is required to do this (hardware or software)?

[d119]

Why not do a console repeat setup so your dispatcher has a button (s)he can press to take it in and out of repeat?

That's what I have set up on my MSF 5000.

[nmfire10]

That nothing like what I'm trying to accomplish here and this is a little more complicated than an MSF5000. I need to steer the voter and dispatcher to one or the other transmitter. And I need the DTMF station/repeat for redundency in case we lose phone lines or other critical infrastructure.

[RKG]

I'm sort of in a hurry, so this will be quick:

We could find no DIU command for Main/Standby, so we used the trick I described above. This doesn't steer the Tx line between two transmitter pairs (the way we do it with SpectraTacs), but rather both radios see the TX command but only one responds.

Which leads you to ask: why not just use the console-generated contact closures to pull in or drop out a relay to achieve Tx steering (like we do with SpectraTacs)? I asked the same question. The answer, apparently, is that if only one of the transmitters is electrically connected at a time, you will see a continuous link failure on the AstroTac.

As for ICR via OTA DTMF, I have seen it done two ways. One involves installing SAM cards in both stations, programming both stations as "repeater" and then wildcard programming both stations so that, until they see "their" DTMF sequence for "repeater on", the repeater is disabled, and when they see their DTMF sequency for "repeater off", it is disabled again.

The other way is similar except that it uses a third-party DTMF transponder, which goes to an Aux Input. Then wildcard programming to turn the repeater on or off via the state of the Aux Input. Note that if you go this route, the NHRC device uses unbalanced audio; to tap it into the Quantar Rx audio, you will have to isolate with a 600-ohm 1:1 audio transformer.

See:

http://repeatercontrollers.com/nhrc-rem ... /index.php

Sorry for being in a rush.

[nmfire10]

The wildcard options. Is that added hardware or is that a flash option. I know the backup transmitter doesn't have it, whatever it is because I asked the tech during the mess yesterday.

[d119]

That nothing like what I'm trying to accomplish here and this is a little more complicated than an MSF5000. I need to steer the voter and dispatcher to one or the other transmitter. And I need the DTMF station/repeat for redundency in case we lose phone lines or other critical infrastructure.

/flame on

You really are a prick sometimes, you know that? Don't flame me because you got caught with your pants down.

I was just offering a suggestion as to the ability to remotely set up / knock down the repeaters, considering you DON'T have DTMF decoders and you DON'T have Station Access Modules. I realize your system is complicated, but please don't flame this MSS technician like he's some noob dork when he tries to offer you help, just because you folks out there can't set things up right in the beginning. I see more gripes from you about how bad your network is than anyone else here on the board. MY $0.02: perhaps you should become a communications technician instead of some Fire Communications Officer/Supervisor, and then you can actually fix this stuff instead of complaining about it.

I'll get back to maintaining the SmartZone system I'm responsible for, I think that's a little more complicated than your conventional Quantar. Jerk.

/flame off

The solution to your problem, as I see it, is as follows:

Add a control station to the console that talks into the repeaters as if it were a mobile. Equip your Quantars with Station Access Modules and DTMF control. Different codes for different stations, or better yet, site 1's ON code is site 2's OFF code, and vice versa, that way they CAN'T be up at the same time. Then have a third "Master OFF" code to knock down both sites so the voter can continue working once your wirelines are restored.

Enable DTMF pages on your Centracom Gold Elite for the ON/OFF/MASTER OFF codes that are slaved to the control station.

This way your dispatcher has one-touch control to the configuration. Obviously you cannot vote the receive audio off of the Quantars without wireline.

Have you looked into Motorola's PTP microwave solutions? These coupled with RAD IPmux equipment would eliminate your issues with loss of wireline. This of course is provided that you have Line of Sight to all your radio sites. The PTP equipment is fairly low-cost compared to Harris/Alcatel type licensed microwave.

You may be able to use the Public Safety 4.9GHz band in your area if your County/State has a license.

As for transmitter steering, you would need DIU's for both stations, and the voted audio routed through the console with a console repeat function (AS I INITIALLY DESCRIBED), and then a Main/Standby BIM/ACIM configuration with the Main BIM/ACIM routed to your primary transmitter and your Standby BIM/ACIM routed to the backup transmitter.

This way your dispatcher can manually steer him/herself to the desired station, and with the console repeat function, the voted audio goes with her.

It would also provide him/her the ability to knock down the repeat path if interference/etc became an issue. You can
interlock this function if you don't want repeat knocked down.

As for automatic transmitter steering, that's going to be a tough one, and Motorola's answer will undoubtedly be "Upgrade to Simulcast."

And not that it matters, but it's not much more complicated than an MSF 5000. The interfacing is all the same, it's all tone control (BIM) with digital keying (ACIM) when you get down to it, whether it's digital or analog (Read: DIU's)

Good luck. Hope SOME of this helps.

[nmfire10]

Umm. Ok. Someone woke up on the wrong side of the bed this morning.

First of all, it isn't MY system. I didn't design it. I'm trying to help the agency who does own make it work properly before someone gets hurt or killed. If you go back read my post, it is NOT a Motorola console. Therefore. your initial suggestion is not a valid one. Had you said all that other stuff, it would have been some of what I was looking for, minus all the console stuff. So before you go off on me, you might want to get YOUR facts straight.

For what its worth though, thank you for the info you did provide after your illegitimate flaming.

[Batwings21]

What D119 said is applicable to any console that has dtmf signalling and one touch paging presets, and io funcions. Does the quantar have a tx inhibit input on the back without the sam card?

[nmfire10]

What D119 said is applicable to any console that has dtmf signalling and one touch paging presets, and io funcions. Does the quantar have a tx inhibit input on the back without the sam card?

I was refering to his initial suggestion of using the centracom's console repeat function. Concidering this isn't a Motorola console, that isn't an option.

We do have DTMF and a constrol station which is what I would like to use for the station/repeat switching. I just need to know what options (hardware or software) might be required to do over the air DTMF station/repeat switching. This is for emergencies when phone lines are down.

[tvsjr]

D119's flame may have been a tad vehement, but he's right. Matt, you're in over your head on this system. That's OK, we've all been there at one point or another. However, you should consider calming down a tad rather than being snarky with someone who has the experience and knowledge to help you out. Perhaps he misunderstood or overlooked some of the info you provided, or perhaps you added that info after his post (note your 7:23pm edit after his 7:06pm reply).

Let's all try to play nice and not get another thread locked, ok?

[d119]

Thank you Terry.

Now back to the topic at hand!

[RKG]

The wildcard options. Is that added hardware or is that a flash option. I know the backup transmitter doesn't have it, whatever it is because I asked the tech during the mess yesterday.

Wildcard is built into the wireline board. If you have the 4-wire board, you have access to "Basic Wildcard;" if you have the 8-wire board, you have access to "Enhanced Wildcard." Since you are running a voted system, you must have a wireline board.

[RKG]

What D119 said is applicable to any console that has dtmf signalling and one touch paging presets, and io funcions. Does the quantar have a tx inhibit input on the back without the sam card?

I was refering to his initial suggestion of using the centracom's console repeat function. Concidering this isn't a Motorola console, that isn't an option.

We do have DTMF and a constrol station which is what I would like to use for the station/repeat switching. I just need to know what options (hardware or software) might be required to do over the DTMF station/repeat switching. This is for emergencies when phone lines are down.

See above: either a SAM card or an external, third-party DTMF transponder one of the relays of which goes to an unused AuxIn and which is paralleled on the Quantar Rx line. Then via wildcard programming you program the station as "Repeater" with "Repeat On" following the active state of the AuxIn and "Repeat Off" following the inactive state of the AuxIn.

The advantage of the NHRC transponder is that it is inexpensive (about $100, versus more than $1,000 for the SAM), and programming a SAM is quite esoteric (and something many radio shops have trouble with). The disadvantage of the NHRC transponder is that it is not Motorola, and some folks balk at mixing M and non-M products in the same system.

A note: as I understand things, in your situation the Main station will go down for lack of utility power and no other power source. However, if utility power comes back, the system will start up again, and someone is going to have to be quite on his toes to knock-down the DTMF-triggered ICR state on the Standby machine, or they will het on one another.

[RKG]

And let me add one thing that may help, re: terminology:

Distinguish between "in-cabinet repeat" ("ICR") and "fall-back in-cabinet repeat" ("FBICR").

FBICR is a Motorola way of triggering ICR automatically in a single-transmitter system when the station senses a failure of the wireline (because it got no comparator-generated Tx signal following receiver qualification on its local receiver).

ICR is simply the status of repeating one's own receiver, using the Quantar internal repeater controller (versus an external repeater controller, which is what a comparator essentially functions as).

FBICR has no utility in a system with both a Main and Standby transmitter.

What you are exploring is a way of controlling plain old ICR for one station.

[nmfire10]

The stuff I edited after was totally unrelated. It was this line "Ideally, I would like to use keying tones to tell the DIU or comparator where to steer. But at this point I'm open to any and all ideas." His first reply was totally off base and his flaming was completely uncalled for. But arguing about his bashing is getting me nowhere so on to more usefull things.

I'm definately distinguishing between the two of those. FBICR is all they have right now, on the main station. That needs to go bye bye. Like you said, it is of no use if you have a backup repeater, that is the whole point of having a backup! Its a design flaw that needs to be fixed. They put in a backup repeater with no way to actually USE IT. What ever possesed them to set it up like this is beyond me. It needs to have a way to setup and knockdown plain old ICR with DTMF over the air. Funny thing is the old system had it. The new system, they forgot. (bangs head on wall).

Luckily, this isn't my system so I can't be in over my head in anything . It is other people in over their head. I'm trying to find them a life preserver. Armed with the knowlege I gain here from you folks, there will be no "umm, umm, uh, i don't think it can do that". You are thinking "why am I asking about this, why don't I just ask the MSS that installed it?" See the above umm umm uh blah blah duh. Remember, this whole whole problem was CREATED by them in the first plac. In my experience, a customer that knows what his equipment is capable of gets a lot more out of the vendor that one who just takes the vendors word for it. Especially this vendor.

So with the wireline boards, I think we are in good shape as far as inputs. Now we just need something to decode DTMF OTA. I assume there is a practical and correct way to hook the DTMF decoder up to the Quantar without re-engineering the wheel?

I like the F1/F2 channel steering and having a channel without TX. That seems to be the most practical and idiot proof way to do it.

This is exactly the information I've been looking for on all counts. I can put all this together as an addenum to my 3 page long failure report from Sunday. Sounds like some reprogramming of the DIU and both stations plus two DTMF decoders will put us on the right track.

[nmfire10]

As I understand it, the Quantar does not have a Vocoder in it so the DIU is what decides whether the Quantar is fed Astro or Analog? And this can also be driven by keying tones into the DIU?

[d119]

Correct. The DIU contains the IMBE vocoder. It allows you to connect 4-wire devices like tone remotes, dispatch consoles, etc. It also spits out the data that is decoded by the ACIM card that gives you aliases, etc. It also handles console encryption/decryption, but that point is moot because you have not mentioned that you are using secure, and being a fire communications network, it's unlikely you use it.

From the book, just for clarification:

The DIU is an interface between the ASTRO fixed equipment (infrastructure) and the analog control equipment. The DIU converts the analog voice from the analog control equipment into digital format and passes it to the fixed equipment. In the opposite direction, it converts the voice coming from the fixed equipment in digital format into analog and passes it to the analog control equipment. The DIU also incorporates the encryption/decryption capability to allow for secure communications.

I believe there are different keying sequences for Analog vs. Digital, and that is how the DIU sets the call up with the Quantar. The DIU and the Quantar are on serial data links.

Remember my suggestion above about programming your repeater on/off codes. The above suggestion will allow you to have a foolproof way to ensure that both repeaters don't come up on the air at the same time, and also give you a "master knockdown" capability of both stations.

Best of luck Matt.

[nmfire10]

I'm told there is also a way to make the comparator latch to a TX site based on where the console is steering it to. For example, you can program the comparator so an F1 command from the console tells it to use transmitter #1 and an F2 command tells the comparator to use transmitter #2. If the console keys up "F1", all communications thereafter will be directed to transmitter #1. When the console keys up "F2", all communications thereafter will be directed to transmitter #2. This is very difficult for me to put into text but the way it was explained to me made perfect sense. In fact, I think that might be how they intended it to work originally but something obviously isn't programmed properly. If this sounds familiar, does it have a name?

The DTMF setup and knockdown definitely needs that idiot proofing. The setup tones for backup would definitely include the knockdown tone for the main and vis-versa. Just in case.

[RKG]

The DTMF setup and knockdown definitely needs that idiot proofing. The setup tones for backup would definitely include the knockdown tone for the main and vis-versa. Just in case.

That is more or less easy enough to do, but I thought in your case a loss of utility power rendered the "main" station dark, in which case it won't see and can't respond to the DTMF command, and, when utility power is restored and the "main" station re-powers up, it will see and respond to Tx commands from the comparator.

[nmfire10]

Good news. I put all this stuff together and brought it back to the table this evening. One of the tech's from the MSS agrees. The LT from the PD is agrees with whatever we all agree works. It looks like we're making actual forward progress already and we're all on the same page about what SHOULD have happened and why it didn't. Fires are being lit under various asses to fix and prevent many of the bad things that happened this weekend from ever happening again. Lots of things, not just transmitter steering. And everyone from multiple agencies is cooperating and actually making an effort to fix it all. We all learned a lot of lessons the hard way this weekend

I can not thank you guys enough for pointing me in all the right directions. You have NO IDEA how much it has helped me and thereby this entire town.

That is more or less easy enough to do, but I thought in your case a loss of utility power rendered the "main" station dark, in which case it won't see and can't respond to the DTMF command, and, when utility power is restored and the "main" station re-powers up, it will see and respond to Tx commands from the comparator.

Yep. When this problem occurred over the weekend, I had the tech from the MSS program the backup station for in-cabinet to get us on the air again. This unfortunately knowing that once main power was restored, we would have both stations repeating. But better that than nothing at all. The tech was waiting for my call to have him come un-program the in-cabinet repeat once main power came back. It wasn't as disruptive as I thought it would be. Most people didn't seem to notice for the hour or so they were both repeating at the same time.

[tvsjr]

While you have them at the table, you might point out that battery-only backups, especially for primary sites, are NOT suitable for public safety work. Proper generators (diesel, LP with a tank, or NG), an auto transfer switch, and *proper generator maintenance* including quarterly servicing/fluid changes/etc. and weekly starts/transfer to generator power are mandatory.

[nmfire10]

That my friend is exhibit A on the list of other lessons learned the hard way and never to be repeated. A standby generator for that site is not an option since it is on private property. However a plan to deploy portable generators to that site and the other receiver locations is being made.

I'm still baffled by the irony. I made that FBICR thread last week with the whole "something doesn't seem right about this setup" thought. I hate when I'm right, and I don't get paid enough to be right about this stuff.

[RKG]

When this problem occurred over the weekend, I had the tech from the MSS program the backup station for in-cabinet to get us on the air again. This unfortunately knowing that once main power was restored, we would have both stations repeating. But better that than nothing at all. The tech was waiting for my call to have him come un-program the in-cabinet repeat once main power came back. It wasn't as disruptive as I thought it would be. Most people didn't seem to notice for the hour or so they were both repeating at the same time.

Not for nothing, but if your "standby" machine is conveniently located, you could rig a simple SPST toggle switch somewhere close to the station. Wire the poles of the switch to (a) an AuxIn and (b) station logical ground. Now, program the station as "Repeater" and with wildcard programming make a table that disables the repeater when the switch is "off" and enables it when the switch is "on". You'll be off the air for however long it takes you (or someone) to get to the room and throw the switch, but you won't be waiting for the MSS guy.

As for battery backups, I agree that public safety should have standby gensets, but even these sometimes fail to start (or to accept load transfer). Most commercial devices are nearly useless, and the Motorola revert board is not much better. But if you want to take the time, I can show you a battery-backed standby power system in use for Quantars that is designed to carry the radio for 2 hours (and, in tests, has gone longer than six hours), does not reduce power when in standby, and costs less than $1,500. (About 90 minutes drive from the Manchester Outback where we had dinner that night.)

[tvsjr]

I should have been more clear. A proper solution involves batteries and a genset/ATS. Proper maintenance will significantly reduce the generator issues, but properly-sized batteries to run the station at a very high duty cycle for long enough to make a site visit and kick the genset or replace it with a spare (always good to have a few Honda EU2000s/3000s kicking about) in the event of a generator failure.

[Lotus54]

I may have missed a reply referring to this, but I'm currently doing sometime similar to what I think you are doing.

2 Quantars with astro modems.
1 Astro-Tac 3000
1 DIU
console type doesn' t matter- tone remote (dual function tones give you a LOT more choices).

I have exactly the same channels in both Quantars. For the Quantar I want to x-mit, I enter the frequency in the TX area. For the Quantar I DON'T want to x-mit, I enter all zeros. Both Quantars go to that channel, but only one x-mits.
This has worked quite well. But all of the channels have the same RX freq, so it works.

I recall there are some problems with 'regular' transmitter steering with this setup, although it shows some places in the software to do it. But I think there is problem.

BTW, when the Quantars receive an analog signal, it passes clear analog audio along the line to the A-Tac. When it gets a Digital signal, it stays in the 'astro-modem' mode.
For transmission it is the same, analog transmissions are clear analog, using astro signaling to tell the base what to do. It mentioned it in the book and I've personally hear it myself. That is how we balance levels, since the analog and digital levels should match as closely as possible.

Sorry if I mis-read the post and this is not what you are asking at all.

Mark

[Lotus54]

I just read the second half of your question.
The quantars can be setup to automatically go into 'stand alone' repeat if they loose connectivity to the A-tac.
You select A-tac in the Quantars and there is a setting there to set it all up.

one problem, if you need F7E it won't work anymore.
You shouldn't have to do any fancy DTMF or anything, it is already built into the system.

I have not personally tested that, since we have other stand along repeaters in the system and don't need those to repeat. PLUS it would require duplexers etc rather than antenna relays.

I can look it up if you like, but just check in the software setup.
Oh yeah, there is a fairly new release of the software, I personally think the windows version is a LOT better than the old DOS one, but perhaps most of that is because it is easier to vew.

Mark

[nmfire10]

We can not have any automatic in-cabinet of any kind. There are two repeaters. It has to be manual control or we'll end up with two repeaters trying to repeat at once.

[Lotus54]

So the two repeaters are co-located and on the same freq?
Guess I missed that.

The DIU can turn on and off the repeat mode, but I understood the transmitter steering doesn't work correctly. Perhaps I'm wrong and it will work.

mark

[nmfire10]

Two separate locations. The DIU is 10 miles away. I need the manual DTMF setup an knockdown for when we lose the phone lines or the DIU/ASTROTAC/CONSOLE blows up. It can't be automatic because if the phone lines go down, they will both lose connectivity and both go into in-cabinet.