MTR2000 AC Fail alarm over air -SOLVED-

Post by **HumHead** » Tue Jan 13, 2004 9:46 pm

What do you have to do to get the MTR2000 to send the AC fail alarm over the air?

Here are some specifics for my particular situation:
1) The unit is set up with a Zetron Model 38 tone panel, so it is configured for base station operation, using the Model 38 as the repeater controller.
2) The unit is not using the standard Argus battery revert kit. Instead it is using a DuraCom setup that is designed to smart charge and maintain the batteries, as well as allowing spilt 12/24V battery banks (Yes, it also includes a relay to disconnect the bank when the MTR has AC).
3) Alarm over air is enabled, and the unit will send a high SWR double beep when it detects an antenna fault. It just is not sending the power fail beep.
4) When the repeater loses AC and goes to battery, the status light slow flashes red, and the error log logs a power supply failure.

The RSS help file states that the Emergency Power Alarm "...is active when the station detecs the AC Power Fail signal."

Am I missing a jumper or sense line somewhere here?

Thanks!

RKG · Post by **RKG** » Wed Jan 14, 2004 7:13 am

I can't answer your specific question.

However, the setup we use requires an independent source of alarming (since our radios never see the loss of AC), and the one with a Zetron 38M is particularly easy: take a relay, power the coils through a wall wart plugged into utility power w/o backup, run a lead from ground to the relay's "common" pin and a line from the relay's "NO" pin to the alarm pin on the Zetron backplane connector. The Zetron programming gives you a couple of options for what is sent during alarm state.

Post by **HumHead** » Fri Jan 23, 2004 9:39 am

First off, my appologies to RKG for not responsing to his input much sooner.

Unfortunately, we couldn't just use the Zetron for several reasons, specific to the way this particular installation is configured (no PL on carrier tail, MRTI port audio that never sees the Zetron, etc.)

The problem was ultimately passed on directly to Motorola where it escalated to the point of having to load our codeplug into one of their machines and let their engineers play with it. Here's what they found:

In the Model 38 instructions, it indicates that you should configure the MTR2000's External PTT Mapping for "Aux. Audio". As it turns out, apparently through a software "bug", with External PTT Mapping set to "Aux. Audio", the station will send general alarms (High SWR, etc.) over the air, but not the AC fail alarm. If you change the External PTT Mapping setting to "Aux. Audio and Wireline" (even if you are not using the wireline) everything works fine, and the station sends the AC fail beep over the air.

Definitely an odd little quirk, but hopefully a bit of knowledge that will come in handy to others in the future when setting up an MTR with an external controller and battery backup.

RKG · Post by **RKG** » Fri Jan 23, 2004 12:23 pm

Now I don't think anyone would have figured that out in a million years. Is there an MTR section in "Model Specific Information?" If so, this little gem should be added there, no?

kmoose · Post by **kmoose** » Fri Jan 23, 2004 1:24 pm

I wonder how many engineers they had to lock in a room, and for how long, to figure that one out? "Sir, the engineers say that they haven't eaten in 4 days." -- "I don't care!!! Not a one of them is leaving that room until they find out what is wrong!"

Post by **alex** » Fri Jan 23, 2004 1:29 pm

RKG wrote:Now I don't think anyone would have figured that out in a million years. Is there an MTR section in "Model Specific Information?" If so, this little gem should be added there, no?

Send it off to Batwing ( a ) ( t ) batlabs.com and I'm sure he'd be happy to.

-Alex