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  #1  
Old 12-17-2019, 06:37 AM
Maverick972 Maverick972 is offline
 
Join Date: Sep 2017
Location: Plano, TX
Posts: 89
Default TRU TRAK Vision 385 Garmin 430 GRT HXr

I upgraded to the vision 385 this year and it is wired up to the Garmin 430 and the GRT HXr.

I also have a switch that is GPS or EFIS.

According to the drawing. RS232 data drives the auto pilot when the switch is in GPS position.

I am assuming that it uses ARING data when in EFIS position as it is wired up that way.

My question is why cannot I control my auto pilot from the HXr or the unit go into GPSS mode when the switch is in EFIS mode. What am I missing? Settings? User error? (More than likely)

Thanks for the help. Sean
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  #2  
Old 12-17-2019, 10:24 AM
Canadian_JOY Canadian_JOY is offline
 
Join Date: Aug 2007
Location: Ontario, Canada
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Check the GRT-provided wiring diagram again. Look hard at it.
You'll see the EFIS/GPS switch actually is a source control switch. It allows you to control which ARINC429 source feeds the autopilot.

When the switch is in the EFIS position, the HX is acting as the source for ARINC429 data going to the autopilot.

This is where things get a bit confusing for many users.

It doesn't matter which unit is driving the autopilot, GPS or EFIS, you MUST manipulate the buttons on the autopilot directly to select its modes of operation. To repeat and clarify, hitting buttons on the EFIS only controls what the EFIS sends out over the ARINC429 data bus. You have to then tell the autopilot what you want it to do with that data. You have to tell the autopilot what mode you want to use.

Set up the HX so that it is supplying valid data to the autopilot. Hit the MODE button on the autopilot to see GPSS (that's the first mode option that appears if the autopilot detects data on its ARINC 429 input). Hit the ALT button to select your altitude mode. Dial in the desired altitude with the rotary knob. Press the knob to select the altitude. Dial in the desired rate of climb or descent, press the knob again and you're now navigating in 3D using data from the EFIS.

(Hmmm, I think that's how it works... I find the autopilot knob-ology has become a reflex so when I'm not sitting in the airplane I kind of forget the button press sequence!)
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  #3  
Old 12-17-2019, 12:16 PM
ALagonia ALagonia is offline
 
Join Date: Jul 2017
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Quote:
Originally Posted by Canadian_JOY View Post
Check the GRT-provided wiring diagram again. Look hard at it.
You'll see the EFIS/GPS switch actually is a source control switch. It allows you to control which ARINC429 source feeds the autopilot.

When the switch is in the EFIS position, the HX is acting as the source for ARINC429 data going to the autopilot.

This is where things get a bit confusing for many users.

It doesn't matter which unit is driving the autopilot, GPS or EFIS, you MUST manipulate the buttons on the autopilot directly to select its modes of operation. To repeat and clarify, hitting buttons on the EFIS only controls what the EFIS sends out over the ARINC429 data bus. You have to then tell the autopilot what you want it to do with that data. You have to tell the autopilot what mode you want to use.

Set up the HX so that it is supplying valid data to the autopilot. Hit the MODE button on the autopilot to see GPSS (that's the first mode option that appears if the autopilot detects data on its ARINC 429 input). Hit the ALT button to select your altitude mode. Dial in the desired altitude with the rotary knob. Press the knob to select the altitude. Dial in the desired rate of climb or descent, press the knob again and you're now navigating in 3D using data from the EFIS.

(Hmmm, I think that's how it works... I find the autopilot knob-ology has become a reflex so when I'm not sitting in the airplane I kind of forget the button press sequence!)
Thatís interesting because that is NOT how my system functions.
I have dual AFS 4500 screens, Garmin GPS 175, ARINC module and a TruTrak Vizion 385. When my select switch is set to EFIS I do not have to touch any of the controls on the TruTrak. As a matter of fact, the only thing I do with the TruTrak is sync the altimeter before takeoff. After that I never touch the autopilot. All input is through the AFS EFIS.
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  #4  
Old 12-17-2019, 01:24 PM
Canadian_JOY Canadian_JOY is offline
 
Join Date: Aug 2007
Location: Ontario, Canada
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Interesting... Now I have a good excuse to go out and burn some more avgas!

BTW altimeter sync in ours comes across from the EFIS automatically so the altitude readout on the 385 always matches the EFIS altimeter.
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  #5  
Old 12-17-2019, 02:43 PM
ALagonia ALagonia is offline
 
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Quote:
Originally Posted by Canadian_JOY View Post
Interesting... Now I have a good excuse to go out and burn some more avgas!

BTW altimeter sync in ours comes across from the EFIS automatically so the altitude readout on the 385 always matches the EFIS altimeter.
Wow, I wish mine did that. Not that itís a big deal to sync them.
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  #6  
Old 12-17-2019, 03:00 PM
Maverick972 Maverick972 is offline
 
Join Date: Sep 2017
Location: Plano, TX
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Quote:
Originally Posted by ALagonia View Post
Thatís interesting because that is NOT how my system functions.
I have dual AFS 4500 screens, Garmin GPS 175, ARINC module and a TruTrak Vizion 385. When my select switch is set to EFIS I do not have to touch any of the controls on the TruTrak. As a matter of fact, the only thing I do with the TruTrak is sync the altimeter before takeoff. After that I never touch the autopilot. All input is through the AFS EFIS.

That is how I was told my system should function. The altimeter does not sync.

The 365 man states that if ARINC data is present then GPSS will be automatic select. When I press MODE only GPS nav is available. I can see on the drawing the ARINC is going to auto pilot.

Could it be a setting in the 430 or the HXr
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  #7  
Old 12-17-2019, 03:28 PM
BobTurner BobTurner is offline
 
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Location: Livermore, CA
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1. The selector switch should be switching the ARINC lines, not the RS232 line. So you need at least a double pole, double throw switch there. (Actually TT says to switch the arinc lines. Trio says to switch arinc and rs232).
2. Make sure the efis and 430 are using arinc out, the TT ports are arinc in.
3. Arinc set to low speed, all units
4. ‘A’ goes to ‘A’, B to B.
5. Some TT models require switching to a particular mode to accept arinc data, others don’t. I have a Trio which defaults to arinc. Other than turning it on and setting the altitude, I never touch it again when controlling thru the HX.
6. I’m assuming you meant 430W. I don’t know what the non-WAAS does.
7 To feed GPSS data thru to the autopilot the HXr must be in GNAV mode.

Last edited by BobTurner : 12-17-2019 at 03:31 PM.
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  #8  
Old 12-17-2019, 08:25 PM
Maverick972 Maverick972 is offline
 
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Quote:
Originally Posted by BobTurner View Post
1. The selector switch should be switching the ARINC lines, not the RS232 line. So you need at least a double pole, double throw switch there. (Actually TT says to switch the arinc lines. Trio says to switch arinc and rs232).
2. Make sure the efis and 430 are using arinc out, the TT ports are arinc in.
3. Arinc set to low speed, all units
4. ĎAí goes to ĎAí, B to B.
5. Some TT models require switching to a particular mode to accept arinc data, others donít. I have a Trio which defaults to arinc. Other than turning it on and setting the altitude, I never touch it again when controlling thru the HX.
6. Iím assuming you meant 430W. I donít know what the non-WAAS does.
7 To feed GPSS data thru to the autopilot the HXr must be in GNAV mode.
Thanks Bob, yes itís a 430W. Look forward to getting this working
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  #9  
Old 12-18-2019, 12:53 PM
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Skid Skid is offline
 
Join Date: Jun 2006
Location: KBUU
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Default TruTrak 385

Quote:
Originally Posted by Maverick972 View Post
I upgraded to the vision 385 this year and it is wired up to the Garmin 430 and the GRT HXr.

I also have a switch that is GPS or EFIS.

According to the drawing. RS232 data drives the auto pilot when the switch is in GPS position.

I am assuming that it uses ARING data when in EFIS position as it is wired up that way.

My question is why cannot I control my auto pilot from the HXr or the unit go into GPSS mode when the switch is in EFIS mode. What am I missing? Settings? User error? (More than likely)

Thanks for the help. Sean
I also upgraded to a Vizion 385 from an older TruTrak A/P after Oshkosh. My setup was a GRT Sport SX EFIS (with external ARINC), TruTrak 385 A/P, Garmin 430 (non WAAS), and a switch for EFIS or 430 to drive the A/P. I also had to add the A/P software to the SX as I did not have that installed, I believe the HXr has it as standard.
I had an issue when I first installed the EFIS where I could not get the GPSS on my old A/P, it turned out to be two wires installed on the wrong pins on the switch.

In learning the new A/P I was told other than engaging the A/P I was to control it through the EFIS, which it did, sort of.

I am nearing a point where I have the process down.

One very important step is to not move the aircraft until the A/P is powered up and ready. The A/P does sync the altimeter with the EFIS so I do not have to set that, with the switch in the EFIS position.
I set the desired altitude on the EFIS by accessing the A/P commands, set desired climb speed, and descent rate, turn on the flight director, select source (heading, ENAV, or GNAV), and arm the approach if necessary. The A/P must be engaged by pressing the large knob, there is no way to engage the A/P from the EFIS, I wish there was. I engage the A/P after takeoff, the EFIS drives the A/P based on the altitude set and the GPS navigation from the 430, assuming the nav source is set to the 430.
The unit worked fine with the 430 except it would climb through the altitude set on the EFIS. Since it was a non WAAS unit I did not get any vertical GPS approach commands from it, I decided to upgrade to an Avidyne IFD440.

I am still working on a process to get the A/P to not climb through the altitude set on the EFIS. As of now I have to disengage the A/P and re-engage it while level, this is not desirable and I am working on why it behaves this way. I have contacted GRT, Trutak, and Avidyne but am still working on the issue.

As of now I believe the issue is not the EFIS or the IFD440, it is the behavior of the A/P. I have spoken to TruTrak/BendixKing twice but have gotten no where with them, each time I get another person at BendixKing support with no record of my previous call.

Once re-engaged while level the A/P works flawlessly with the EFIS and IFD440.
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  #10  
Old 12-18-2019, 04:13 PM
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catmandu catmandu is offline
 
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I agree it would be nice to have the Vizion capture altitude right off the bat.

My current technique is to set the initial altitude in the EFIS and control initial rate of climb with the Vizion (typically 800fpm). 200 feet shy of your initial target altitude set in the EFIS, roll the rate of climb to zero on the Vizion. It then captures and holds the target altitude. After that, all changes can be made solely with the EFIS.
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