In-Cabinet fallback repeat [UPDATE... Not good!]

[nmfire10]

Can someone explain exactly how in-cabinet fallback repeat works on a quantar? I can't get straight answers here and I'm concerned the information at dispatch is not very accurate about how to handle a radio or wireline problem. There is a main and backup repeater, both quantars. There is a DIU and an astrotac. Will it go into fallback as soon as it is receiving but getting a transmit from the voter?

[Batwings21]

Not completely sure with the diu, but with conventional clear analog it will key when it receives a signal from the internal receiver, if it gets a wireline signal then the wireline takes priority. If no wire line it should repeat from the local rx.

[xmo]

If the station is used in a voting environment it will not automatically repeat in cabinet just because the wireline signal isn't there.

The station must be explicitly programmed for fall back in cabinet repeat.

Since you mention that there are main and backup repeaters - if these are selected by steering wirelines through CCII aux-I/O - it is probable that you DON'T have fall back in cabinet repeat in order to avoid the possibility of two repeaters activating simultaneously.

The only way you can know how your system is supposed to work is to have your service provider explain to you how the system is programmed.

[RKG]

FBICR is basically an automatic way to invoke ICR if the comparator fails. The logic is that if the station's local receiver is qualified but no key signal is received over the wireline before expiration of the FBICR timer, the station will fall back into ICR mode until the wireline signal is restored.

As others have noted, it is not employed if there is an externally switched path to a standby or backup transmitter.

You can program a Quantar for manually-invoked ICR by programming it as "Repeater" (vs. "Station") and then using wildcard to "disable repeat" until receipt of some input. The input can be a contact closure via one of the aux inputs or receipt of a DTMF or MDC signal over the air, if the station is equipped with a SAM card.

[nmfire10]

That is what I thought, I just wanted to confirm.

The poorly worded documentation says that it is programmed to do so. However I see the same problem as you guys. How the hells does it know which one to use if there are two repeaters.

I believe the DIU is steering which transmitter to use when everything is working normally, using keying tones from the console to tell it what to do. But as for what it does when the wireline is gone, I'm not sure how it will work and neither is anybody else. Is it possible to use DTMF setup and knockdown for that?

[FMROB]

Good luck finding any documentation on any of the either in the service and programming manual. The moto literature leaves alot to be desired.

[nmfire10]

I've determined that the documentation and description of operation from everyone involved is all wrong. It is physically impossible for it to work the way it is being described. The whole thing would have melted down into a black hole by now if it did.

[RKG]

I've determined that the documentation and description of operation from everyone involved is all wrong. It is physically impossible for it to work the way it is being described. The whole thing would have melted down into a black hole by now if it did.

Want to elaborate?

[nmfire10]

I'll try. This is hard to put in text so bear with me.

There is a main transmitter/receiver. There is a backup transmitter/receiver. There are two other receivers. All are connected to an astrotac voter and DIU30000.

The console has a button for this system that changes "channels". But obviously it isn't actually changing channels. The channel keying tones are simplying telling the DIU3000 what to do. This is what it says:
F1: Main Analog
F2: Main Astro
F3: Backup Analog
F4: Backup Astro

The documentation as well as verbal communication from those with "knowledge of the system" say this steers which repeater is active AND controls where the dispatcher talks from. So in theory, with it set for Main Analog, it would steer the voter and the dispatcher to the main site and dispatch would be analog. With it set for Backup Astro, it would steer the voter and dispatch to the backup site and dispatch would talk in astro. This makes logical sense and it is what everyone thinks it does. I'm reasonably sure that the only thing it actually does is steer where and how the dispatcher talks. It has absolutely no effect on steering the voter's transmit site. The voter is always going to TX on the main site no matter what buttons are pushed.

There is also documentation stating that in the event of phone line failure, the main site will go into ICFBR. This further proves that the console does not steer the voter. If it did, every time they put the system on backup, the main site would go into fall back and both transmitters would be going at the same time (the black hole). However, I'm almost positive they do in fact have ICFBR programmed because the chief has instructed everyone to go analog during major storms in case the phone lines go out. Makes sense. Actually, it would make sense for them to never have gone to astro in the first place but that is another issue for another day.

There is also no manual control of the sites by DTMF or anything. So lets say the main site gets hit by lightning. There is no way to steer the voter to backup and there is no way to put the backup site into in-cabinet.

This is the same system which was the subject of this thread. I have to find these pictures somewhere It has been long repaired but still....
http://batboard.batlabs.com/viewtopic.php?f=10&t=29071

[RKG]

OK: I missed the point that this was an Astro system, in which case I agree you're into another world. In Astro systems, in essence, all controls are via DIU commands, and if use an "old" console, you have to program the DIU to convert FTs to DIU commands. As I recall, the DIU command set was kludgy.

In "old" systems, we controlled Main/Standby switching by using an Aux I/O output to pull in the coil of a DPDT or 3PDT relay. The Tx line from the comparator went to the common terminals of poles 1 and 2; the NC poles went to the Main transmitter and the NO poles went to the Standby transmitter.

In such an application, I agree that there is no function for the Quantar's built-in FBICR function to serve and it was never enabled.

In an Astro set up, we could not find a Main/Standby command in the DIU set. So what we did was to program two channels in each of the transmitters. In the Main station, Ch. 1 was Tx capable on our freqs and Ch. 2 was RXO; in the Standby station, Ch. 1 was RXO and Ch. 2 was transmit capable. We then defined a Main/Standby icon to toggle a channel change between Ch. 1 and Ch. 2 simultaneously in both stations.

Sort of like using duct tape to make a state-of-the-art rocketship work.

[nmfire10]

So you had TX audio and keying tones going to both transmitters at once, but only only one of them was on a channel that could transmit? Innovative. And hey, duct tape worked in Apollo 13 so there is nothing to be ashamed of.

[MassFD]

So you had TX audio and keying tones going to both transmitters at once, but only only one of them was on a channel that could transmit? Innovative. And hey, duct tape worked in Apollo 13 so there is nothing to be ashamed of.

We have our system set up almost the same way except we use the XMITINH command in wildcard to keep the unselected xmitter from keying up. This is a non voted 3 site system (in cabinet repeat)

Only problem with this is if you loose the wireline to the main site you can still select another site but you cannot shut down the in cabinet repeat on the main site as you have no wireline to it. I am working on a way to XMITINH it via wireline loop current supervision, loop current drops and a relay would close a contact to the quantars aux io and XMITINH the site. I thought of using DTMF in the input freq to control it but dispatch does not have a control station to send the DTMF as the system is on wireline>

[RKG]

FBICR was defeated in both machines, so that if wireline was lost to Main, while it wouldn't see the Channel Change command, it also wouldn't see anything else and would therefore stay silent.

In general, the automatic FBICR feature is not compatible with a system that has two transmitters, simply because it is triggered by the failure of the station to see a comparator-generated key signal addressed to itself.

[nmfire10]

Well, all my worst fears just came true today. Everything I thought and predicted came true. We just had a storm last night that was arguably the worst weather incident we've had in 10-15 years, maybe even since hurricane gloria. Town wide power failure except for one main road. Trees and power lines in pieces all over the place. Transformers popping off left and right. All started around 6pm on Saturday night. Townwide power was out by 9pm.

Only the backup transmitter has generator power. Remote receiver sites were battery back-up only, no generators. The batteries all ran down overnight and those sites failed. The main site for PD was battery backup only, no generator. The batteries ran down at about 9am and the main site failed. There is no way to steer the voter to the backup transmitter. There is no DTMF setup and knockdown. The backup site doesn't even have the wildcard module to do it. For some unknown reason, we lost the receive audio from the backup transmitter but we could still transmit from dispatch from the backup transmitter. All the other receiver sites were dead. The only thing that worked was dispatch transmitting in the blind off the backup transmitter. No receive. No repeat. No tones for dispatching. Nada.

Batteries were failing left and right at the cell sites so we were losing our ability to talk to officers and the ambulance on cell phones and losing our text messaging just as fast. It was a really helpless feeling knowing you can just hope the message is getting through.

I had to call the MSS and have them come to town and reprogram the backup transmitter for in-cabinet repeat. Once that was done, we had limited communication since the backup site alone doesn't cover the whole town very well. Thank god I already knew what was happening and why to have them go do that or we would have been DOA even longer. Then of course once power was restored, they had to come de-program the in-cabinet repeat since the main site was repeating as well. What a nightmare.

At about 6pm, power was restored to most of the town and I got all my sites back up and running again. Tylonol has never tasted so good.

[kcbooboo]

You missed all the fun we had in Hamden Saturday morning.

Power went out to the whole town at 0740 due to an equipment malfunction. Let's just say that calling out one crew at 9am was not what I'd call "scrambling to fix the problem". Cable TV batteries lasted just over 3 hours, and once they went down, so did my VoIP phone service. Luckily I have satellite TV as well. My neighborhood got power back at 1345. The northwest corner of Hamden got it back around 1800. They had to switch EVERY power junction from the main Hamden (Mix Avenue) feed to secondary out-of-area feeds, and that takes a lot of time, even with three crews working during the afternoon. I think all but a few isolated customers were back on by 2100.

My whole-house generator got quite a workout running flawlessly for 6 hours.

Then around 6pm the storm came, and that took care of the rest of the state...

Bob M.

[MassFD]

We got hit on Long Island around the same time, lost power to 2 sites but both have battery backup and generators so we had no problem except for a firehouse with water coming out of a 600 amp main distrubition panel. Someone left a cover off a junction box on the siren on the roof.

And then we have the resident down the block from HQ who now has an Audi with about 2000 lbs of tree sticking out of the sunroof, the tree missed our interbuilding communication cable on the way down but dic take down the entire 3 phase LIPA primary (the cause of our 2 site power loss)

I am also looking for a way do knock down the repeater in a quantar on wireline loss so it does not beat up the backup site. Since I have a DC loop current that flows when my wireline is connected I am thinking of using it to disable the quantar repeat on loss of current.

[GlennD]

About ten years ago on the day that the paging satellite failed our primary site went off the air.

We run off of a full time UPS powered by a 540V battery bank. This is charged by Edison or a massive standby generator.

After the scheduled generator test the cam in the transfer switch broke and left the site with no AC power. This would have been a urgent problem but not the end of the world. The big problem was the automatic pages went nowhere.

The UPS died after several hours but the 48V bank for the microwave equipment was still up when power was restored.

Even with the best planning Murphy still rules!

[chpalmer]

In our area we have several transmitters that rely on phone lines to dispatch. We've installed small repeater makers on a couple of sites with backup pl tones. Dispatch has a backup basestation that can talk through these stations if needed. The cars also have these channels programmed in them.