AXP340 doesn't start in gnd mode
Printed From: Avidyne
Category: Avidyne General
Forum Name: AXP340/322 ADS-B Transponder
Forum Description: Topics on the Avidyne AXP340/322 ADS-B Transponder
URL: http://forums.avidyne.com/forum_posts.asp?TID=879
Printed Date: 25 Dec 2024 at 2:34pm
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com
Topic: AXP340 doesn't start in gnd mode
Posted By: M20J
Subject: AXP340 doesn't start in gnd mode
Date Posted: 27 Nov 2015 at 12:04pm
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My AXP340 is supposed to be set up to turn on in ground mode and to automatically switch to alt at a target speed. That's what the avionics shop told me, and I went through the setup menu and I believe everything in there indicates that too, but every time I turn it on, it starts in ALT mode and the only modes available are ALT, STBY and ON. According to the book, it should also turn on when power is applied to it, but I have to turn it on manually? The IFD440 (installed at the same time) does come on with the AV Master switch, but the axp does not? Any suggestions? |
Replies:
Posted By: oskrypuch
Date Posted: 27 Nov 2015 at 12:41pm
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The AXP will stay off, if it was previously manually turned off. But, IIRC in addition there is a setup option to have it follow the power state (or NOT). GND mode, and auto cycling takes a few things to be set up correctly as well. It sounds like some things may have been missed in the config setup. * Orest |
Posted By: M20J
Date Posted: 27 Nov 2015 at 1:05pm
| I'll look through the config menu again. Any idea what might be missing for GND nice to work? |
Posted By: oskrypuch
Date Posted: 27 Nov 2015 at 1:57pm
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It is just a guess, if one thing is off ... Could also be an install issue, not running the ground sense from the IFD540 (or a squat switch) correctly.
* Orest |
Posted By: oskrypuch
Date Posted: 27 Nov 2015 at 2:06pm
From the install manual ...
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Posted By: Gring
Date Posted: 27 Nov 2015 at 7:28pm
| Mine does the same thing. You need wither the squat switch, or a GPS connection to simulate the squat switch so it auto switches. |
Posted By: M20J
Date Posted: 27 Nov 2015 at 8:23pm
| I have an ifd440, and the shop that installed them told me it was set up for auto air/ground |
Posted By: Dlesh123
Date Posted: 27 Nov 2015 at 10:10pm
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Our 540/340 combination was working fine, then we accidentally uploaded the sim settings to our 540, screwed everything up, including causing our transponder unit not to go to grnd mode. Unfortunately the shop did not tell me which setting they had to change to get it to work. I would be willing to bet its a setup issue. |
Posted By: oskrypuch
Date Posted: 28 Nov 2015 at 8:46am
What shop did you use? * Orest |
Posted By: 94S
Date Posted: 11 Dec 2015 at 11:17pm
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This is not exactly the same as M20J's issue, but it seems like it fits into this thread anyways. I also have a 540 and AXP340 transponder. The transponder is setup to auto switch to ALT based on the GPS ground speed from the 540. I've noticed that the AXP starts up and stays in ALT mode until the IFD is done with its startup and self test. Which is typically only a few seconds. Today though, while updating the nav database I noticed that the AXP stays in ALT mode the whole time the IFD is updating. Is this possibly something wrong with my installation? Or is this "normal"? It seems to me that the AXP should start in GND mode and then only switch to ALT when the ground speed exceeds the preset point. Would these ALT replies cause any issues for ATC?
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Posted By: oskrypuch
Date Posted: 12 Dec 2015 at 12:27am
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The FAA now requires that you maintain your transponder in ALT mode on the ground. Mode S "GND" is OK as well. So no issues with the squawks. Believe this was a change in the logic to address the potential for the transponder NOT cycling, if the even that the FD malfunctioned. * Orest |
Posted By: Royski
Date Posted: 14 Dec 2015 at 9:07am
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I had a similar issue with my initial installation. The installer assumed the air/ground switching worked like Garmin and failed to install the "squat switch" wire between the 540 and 340 identified in the installation manual. I had that corrected by another shop. |
Posted By: Awful Charlie
Date Posted: 09 Aug 2016 at 5:56am
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I've just come back from having my 540/440/340 install done. Like a previous poster, I'm having problems with the auto-switching, but I have an airspeed switch, so looking to make a trip back to get this connected and hopefully resolve that problem. However, I've not managed to read to solution to getting the AXP340 to power up with the avionics master which my GTXS330 used to do - it certainly doesn't power itself up when it was last turned off via the master - has anyone got a solution? Ben |
Posted By: PA20Pacer
Date Posted: 09 Aug 2016 at 8:12am
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Hi Ben- If my AXP340 is turned off using the switch on the panel, that switch will need to be pressed to turn it on again. If the AXP340 is powered down using the avionics master, it will power up as soon as the avionics master is turned on again. It sounds as though this is different from what you are seeing, but I do not recall any setting that changes the power up/power down behaviour. I hope that we hear something from someone more knowledgeable. Regards, Bob ------------- Bob Siegfried, II Brookeridge Airpark (LL22) Downers Grove, IL |
Posted By: M20J
Date Posted: 09 Aug 2016 at 9:23am
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Hi Ben, I got a warranty replacement for mine because of this issue. Let your shop know and they should order you a replacement. |
Posted By: Gring
Date Posted: 09 Aug 2016 at 10:16am
| Before you mail it off for warranty, be sure it is wired correctly. There is a connection to power that is required for it to turn on with the master. My original installation would not turn on without the additional wire. |
Posted By: chflyer
Date Posted: 09 Aug 2016 at 11:22am
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My AXP340 behaves the same as PA20Pacer describes. Power supply is from the avionics bus, so the unit only comes up when the avionics power is turned on. If it is on and I turn it off manually, then it stays off through external power cycles until I manually turn it back on. ------------- Vince |
Posted By: Awful Charlie
Date Posted: 10 Aug 2016 at 2:55am
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Thanks all. I've got an appointment back at the shop for October to connect up the air speed switch, and will try some more testing in the meantime to see if I can get the unit to come on with the master - if that fails then the unit will have to go back. At least I've still got the 330 to cover me for the time it takes to get from Europe to the US and back! Gring - if you can point me (and hence the shop) at anything about the extra wire that would be appreciated - so far neither of us have been able to find a hint about that |
Posted By: chflyer
Date Posted: 10 Aug 2016 at 4:09am
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That extra wire is news to me too, so I'm interested to see Gring's response. ------------- Vince |
Posted By: MysticCobra
Date Posted: 10 Aug 2016 at 11:07am
This is not consistent with the AXP340 Installation Guide ( http://www.avidyne.com/files/downloads/600-00308-000.pdf" rel="nofollow - here ). The wiring diagram does not show any power-related wire other than the primary input on pins 11 and/or 12. Per p. 23:
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Posted By: M20J
Date Posted: 10 Aug 2016 at 11:12am
| My shop told me that it is a known issue. The first replacement unit they put in also did this, they got a second replacement the following day and that fixed it. |
Posted By: TomH
Date Posted: 10 Aug 2016 at 11:13am
It's in the IFD440 installation Manual. Page 1 of Section two on page 34 has a note under Plug & Play Considerations. And then in detail beginning on page 82 in section 6.12.
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Posted By: MysticCobra
Date Posted: 11 Aug 2016 at 8:18am
| TomH, the mystery wire in question is in regard to having the AMX340 turn on when power is applied, vs. having to turn the unit on individually every time the plane starts. |
Posted By: Awful Charlie
Date Posted: 26 Oct 2016 at 11:59am
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Just to close this off, the Ground/Alt switching was due to the Grey code being connected in addition to the RS232 and is now sorted, the power on with avionics is going to need the unit swapped out |