Motorola SLR5000 any ideas to make it broadcast a tone when on battery

[tropiradio]

Hello,

I do have an SLR5000 series repeater operating in analog only mode and that normally operates on AC power, but it also has a deep-cycle marine backup battery in case the mains power fails and a separate Victron smart charger. It works fine, but problem is one never knows when the repeater has fallen back onto battery operation so as to perhaps take some measures in order to minimize usage to extend the battery operation to the maximum, or at the very least to be aware of that battery operation has come into effect and not letting it run down the battery completely is also a good idea to avoid shortening the service life of the battery. That of course is another separate matter, but right now creating some sort of over-the-air alert is my main priority.

Not aware of any programmable pin on the rear DB25 connector that would change state once the repeater is operating on battery, or if AC has failed. On this last option, and it would certainly not be my most favorite one, is to get a wire to the internal power supply DC output so as to detect when it no longer is online. Another (external sensing) option that comes to mind is just sensing the AC mains with a 120V coil relay on the same outlet that feeds the repeater. That would certainly avoid having to pull the cover off the repeater and sounds like the easiest AC-present sensing solution.

But once I do have a signal that changes states when the power mains have failed and the repeater is operating on battery power, how could one insert (ideally) a short beep tone that only would be transmitted on the tail, or when the person currently talking releases its PTT (repeater "COR" changes state).

If this where for a more conventional older style repeater where one could easily get into the repeat audio path it would be quite easy. But on the SLR the only way to get into that audio path is to disable internal audio routing, as for example when an external controller would be used. But hoping to keep it simple so would not have to reconstruct the whole audio path aside from injecting the short beep. Not aware of any other ways to broadcast an alert in any other form, not necessarily audible. Also it does not help not having the detailed service manual of the repeater, not even sure it is available, or someone has posted it somewhere out there in PDF.

I am also aware of RDAC, and that it would allow to check on the whole status of the repeater, but I am trying to avoid having to go that route as it would be a bit of overkill.

I'm open to ideas, anything that might accomplish one knowing that the repeater is on battery while keying it up would be fine. Thanks in advance for any suggestions.

 

[jeepsandradios]

Site I was at last week had 2 XPR mobiles at the site hooked up to a power fail relay in the shelter. When power fail happens its set to send a status to the radio at dispatch. We used to do this with GM300's back in the day with MDC. Maybe something like this would work ?

For power fail relay I have used a 12v relay and a wallwart with good success. The wallwart seems to filter a quick blip where the 110 powered relays will drop. YMMV

 

[tropiradio]

Might be an easy option but would be preferable not having to use any additional radio equipment and also this is a conventional analog system so no way to send a status to dispatch, even if there was even a dispatch. Rather wanted to make the repeater itself do the sensing and broadcasting of the brief tone to indicate battery operation so any user can be made aware of this, not just a dispatcher. Would have though someone out there might have come up with something like this already as it would probably fill a desirable need at almost any SLR that has battery fallback backup.

The SLR will set a minor alarm if the battery is disconnected while it being enabled in CPS, but anything to do with the actual power operational status (AC or DC) was completely ignored. Would have been nice to have one of the IO pins do some power source status, but I keep on dreaming. A minor alarm will also be set if battery gets low, but again no way of knowing this remotely. Ok maybe RDAC, but as before, it'd be overkill in this case to use it just for that one purpose.

 

[emacs]

I will have double check when I’m at a PC with CPS, but I believe you can assign one of the GPIO pins on the DB25 to go low/high when AC power is lost. There is also an aux mic input and programmable PTT input on the DB25, so you could wire in a board like this that plays a prerecorded audio file when the associated GPIO pin changes state.

Getting it to play the audio every time a transmission ends is trickier, you would somehow have to use the COR/PL/DPL output of the repeater to trigger the sound when there is no carrier, but only once. That way, transmission ends, carrier/PL/DPL signal drops, audio board keys up the PTT input and sends audio into the aux mic input, then stops sending audio and releases the PTT trigger. All the while you need to make sure this only happens when AC power is lost. Sounds like a fun experiment!

 

[firefive76]

I have these at some of my sites. Good to monitor temperature, and will text or email up to 5 contacts when the temperature or humidity is out of your set ranges, or for a power failure.

 

[tropiradio]

I do have one of those GSM remote control boxes similar to the one at the link and use it when I want to be notified of a preset sensing of an event or condition change by text message. But for this repeater that would not be practical as it only notifies one person, but it should the users are the ones that should be notified ideally through the repeater itself while they are using it. Thank you for the suggestion anyhow.

 

[tropiradio]

I will have double check when I’m at a PC with CPS, but I believe you can assign one of the GPIO pins on the DB25 to go low/high when AC power is lost. There is also an aux mic input and programmable PTT input on the DB25, so you could wire in a board like this that plays a prerecorded audio file when the associated GPIO pin changes state.

Getting it to play the audio every time a transmission ends is trickier, you would somehow have to use the COR/PL/DPL output of the repeater to trigger the sound when there is no carrier, but only once. That way, transmission ends, carrier/PL/DPL signal drops, audio board keys up the PTT input and sends audio into the aux mic input, then stops sending audio and releases the PTT trigger. All the while you need to make sure this only happens when AC power is lost. Sounds like a fun experiment!

There is actually a GPIO pin option that says "AC Power Failure". But it is described as "Allows the user to enable/disable the AC Power Failure. When enabled the repeater shows the alarm related to the AC failure."

When I first read this I understood it as being an INPUT that enables or disables the repeater from logging or showing an alarm upon an ac power failure condition. Not as an output pin that would become active when the AC failure occurs, which is what I am looking for. I never tried this function yet to be sure how it works, but the description context seems to suggest is an input pin. But I may be wrong. Has anyone tried to use this function or might have more knowledge about the way it works and can confirm if this an input or output pin?

I seem to remember if the aux mic is enabled the internal repeat audio path is disabled as the repeater assumes "base station" mode. As an example the instructions for using a Z38 controller with the SLR I think among others use the aux mic input pin for the Tx audio, and at the same time enabling it disables internal repeat audio so it will only flow though the Z38 as required. However I last read this document quite some time ago, so a bid foggy on the finer details.