GRT ARINC help please.

I installed an ARINC module to work with my Sport EFIS. I have the original Sport before it was an SX or EX. It has 4 serial ports. My A/P is on #1, transponder on #2, my GPS on #3, an I have plugged the arinc into #4, which previously was unused.

I am getting a warning that there is "no data from arinc module." The only setup change I made after plugging it into the harness Jesse Saint wired for me was to toggle the arinc connected setting to YES.

I spoke with Mark at GRT this week about the data problem and he said I needed to tell the efis which serial port the arinc was on, but not where to do that. I presumed it would be obvious but I can find no other place to do that in the setup menus. I thought maybe I needed to set the input or output to ARINC but it is not a choice.

Can anyone help wit this? Also, any other changes I may need to make in the serial port 4 input or output options once I get the arinc to work?

I'm in my hangar now and hope to be able to resolve this before inleave. Thanks a ton! Andy

GRT ARINC

Looks like this may help,
http://www.grtavionics.com/ARINC 429 - External Module Rev E.pdf

Thanks I've see that. As far as I can tell, I have it wired correctly and it looks like all you need to do is toggle the arinc setting to YES. I've done that. But it doesn't work.

I'm not very knowledgeable about avionics but I presume the arinc sits between the input (my efis), and the receiver of the data, which is my A/P. To be honest, I'm just not sure how these things talk to eachother.

I'm still stuck.

Settings

This is what the Horizon manual says about the settings being the same for input and output.
ARINC Module
This setting is required to be YES if the EFIS Horizon has an ARINC-429
Module installed. This setting will also showthe autopilot gains at the bottom of this page when selected.
If YES, the Receive and Transmit setting must be set to the same setting as
the radio unit installed, ie. GNS 430, etc.
The ARINC Input Counter counts packets received from the ARINC module
and is useful for troubleshooting.

Thanks. I'm going to wrap it up for the day and try to absorb everything. The answer may be in here someplace.

It also sounds like on the older units the arinc attached was just a simple toggle between Y and N.

Hi Andy,

I just had a look at my spreadsheet for my dual Sport HS EFIS. In Gen SetUp
ARINC Connected Yes
ARINC Receiver Rate Low
ARINC Transmit Rate Low

further down in Gen Setup
ARINC Send Sel Crs On
ARINC Sel Crs Mod Unlimited

In Display Unit Maint
ARINC Status Change to activate
I think this is where you turn on ARINC VOR/ILS Inputs and ARINC GPS inputs which will then show on Gen SetUp.

Let me know if this works. If not I can have a look at my airplane.

Jim Butcher

AndyRV7 said:

Thanks I've see that. As far as I can tell, I have it wired correctly and it looks like all you need to do is toggle the arinc setting to YES. I've done that. But it doesn't work.

I'm not very knowledgeable about avionics but I presume the arinc sits between the input (my efis), and the receiver of the data, which is my A/P. To be honest, I'm just not sure how these things talk to eachother.

I'm still stuck.

Click to expand...

Make sure you are using the ARINC OUT (A and B) from the module, to the ARINC IN for the autopilot.
Check the efis menu for serial port configuration, select number 4. Turn thru the options. Is there an option for external arinc box?

h&jeuropa said:

Hi Andy,

In Display Unit Maint
ARINC Status Change to activate
I think this is where you turn on ARINC VOR/ILS Inputs and ARINC GPS inputs which will then show on Gen SetUp.


Jim Butcher

Click to expand...

This looks promising Jim. Everything before this is as near to what you offered as my unit allows for choices.

If I go to the diplay unit menus I have 2 arinc choices. One is to load arinc software. I tried to load it (from nothing) and it failed...seemingly obviously. The other menu choice is ARINC staus. That takes me to a full submenu of arinc-only options but all are zeros or old invalid references, PARTICULARLY ARINC Version and ARINC Date.

I am going to search the webite to see if there is an arinc software download. I don't have a computer hear in the hangar (or heat or good lighting or food or... ; ) ) but it might be insightful.

Thanks!

BobTurner said:

Make sure you are using the ARINC OUT (A and B) from the module, to the ARINC IN for the autopilot.
Check the efis menu for serial port configuration, select number 4. Turn thru the options. Is there an option for external arinc box?

Click to expand...

Bob, I paid someone who knows what the are doing to wire it. At this point I am going to presume it is correct. May have to check it down the road though.

Sadly, there is no ARINC choice for sp#4 input OR output.

AndyRV7 said:

Bob, I paid someone who knows what the are doing to wire it. At this point I am going to presume it is correct. May have to check it down the road though.

Sadly, there is no ARINC choice for sp#4 input OR output.

Click to expand...

I re-read the GRT instructions and you are right. Once you selected ARINC on, it defaults to port 4.
If you have a pin puller, try this: pull the GPS out of port 3 input, and put it in the new port 4 serial input coming out of the ARINC box. Configure port 4 input the same as port 3. Does the GPS still work as before? If yes, then the box is hooked up correctly. If no, then either the box, wiring, or set up is wrong.

GRT ARINC

Andy,
I've been through this, I chased the same issue for some time. I was sure I had everything wired correctly yet GRT tech support kept telling me the likely issue was a wiring issue.
I went through the settings with Todd at GRT and confirmed they were correct.
Full disclosure; I did have a switch in my setup as I have a TruTrak A/P and can drive the A/P from the 430 or the Sport SX.
I ended up tracing the wires all the way from the ARINC to the 430, I assume you are connecting a 430. Turned out to be 1 wire flipped at the switch.
Drove me absolutely nuts for weeks.

Andy,

I may have taken you down a blind road.

Your ARINC module must be connected to serial port 4 in and out on your EFIS. That is pin ARINC pin 4 to EFIS pin 33 and ARINC pin 3 to EFIS pin 37. Also the ARINC module requires 12 volts on pin 5 and ground on pin 1.

The test Bob suggests will test if the wiring is correct.

I take it you are using this to drive your autopilot. The settings I listed in the previous post are to interface a GNS430 to GRT EFIS.

You should have connections to pin 5 and pin 9 of the ARINC plug (on the top of the box) going to your autopilot.

Have you asked Jesse for help? He is very helpful.

Jim Butcher

Skid said:

Andy,
I've been through this, I chased the same issue for some time. I was sure I had everything wired correctly yet GRT tech support kept telling me the likely issue was a wiring issue.
I went through the settings with Todd at GRT and confirmed they were correct.
Full disclosure; I did have a switch in my setup as I have a TruTrak A/P and can drive the A/P from the 430 or the Sport SX.
I ended up tracing the wires all the way from the ARINC to the 430, I assume you are connecting a 430. Turned out to be 1 wire flipped at the switch.
Drove me absolutely nuts for weeks.

Click to expand...

I went home and got some food and then spent the last couple hours reading the setup instructions. At this point there are so many thing I may have changed or were even setup incorrectly already. But while I was doing this, it just seemed like more of a good idea to verify the wiring before I go any further. I appreciate the encouragement.

I also have a toggle switch to flip flop between two GPS signals. One is the GRT EFIS, and the other is a G3X on the copilot's side. But I presume the G3X isn't a problem because I had the switch on the GRT side the whole time.

h&jeuropa said:

Andy,

I may have taken you down a blind road.

Your ARINC module must be connected to serial port 4 in and out on your EFIS. That is pin ARINC pin 4 to EFIS pin 33 and ARINC pin 3 to EFIS pin 37. Also the ARINC module requires 12 volts on pin 5 and ground on pin 1.

The test Bob suggests will test if the wiring is correct.

I take it you are using this to drive your autopilot. The settings I listed in the previous post are to interface a GNS430 to GRT EFIS.

You should have connections to pin 5 and pin 9 of the ARINC plug (on the top of the box) going to your autopilot.

Have you asked Jesse for help? He is very helpful.

Jim Butcher

Click to expand...

Hi Jim, I did speak to Jesse from the plane. But he had a difficult time without seeing what I was looking at. He's been very willing to help when I've called. A lot of this is just me coming up a learning curve I didn't know I was going to have to come up. Everything worked flawlessly until I installed the arinc.

I'm going to get a good look at the wiring and then call GRT back for a long talk. I should have all the facts I need at that point about the wiring and how the setup is currently configured.

BobTurner said:

I re-read the GRT instructions and you are right. Once you selected ARINC on, it defaults to port 4.
If you have a pin puller, try this: pull the GPS out of port 3 input, and put it in the new port 4 serial input coming out of the ARINC box. Configure port 4 input the same as port 3. Does the GPS still work as before? If yes, then the box is hooked up correctly. If no, then either the box, wiring, or set up is wrong.

Click to expand...

Thanks Bob. Will do!!

Andy,

One last thought. Be certain that the power for the ARINC module and the EFIS come on at the same time. At one point I had two different power sources and if the ARINC was not powered when the EFIS booted, I got the ARINC not detected message.

Jim Butcher

OK, I'm back. I traced all the wiring on Sunday and I wonder if I have found a problem tonight while looking at all the pictures I took. Everything seems to check out (in my mind) except one wire. My installer referenced the EFIS serial port 4 input as hole 33 on the 37 hole plug. It receives the orange wire in my plug pic below. If I am not mistaken the wire in in plug 32 instead???

The yellow wire that runs from the ARINC back to the EFIS is supposed to be in hole 37, which is the serial port 4 output. I think this wire is fine as is.

All other wiring seems to be correct between the EFIS, the ARINC, and the TruTrak A/P.

I looked at the sample wiring diagram GRT has for a dual EFIS setup but if you ignore the actual intended system, it DOES reference pin 33 as (SL-30) Serial 4 Rx and (SL-30) Serial 4 Tx as pin 37 (so the serial 4 input and output). So I guess my installer was on the right track but maybe put the orange wire one hole away from where it needs to go???

What do you guys think??? Thanks!! Andy

It looks like you found the problem. Pin 3 on the ARINC should go to pin 37 on the screen. Pin 4 on the ARINC should go to pin 33 on the screen.

Bingo

Andy,
I agree with Jesse. I believe you have found this problem.
Wiring issues drive me nuts.

Thanks guys. I'll be away from the plane for a week or so but will report back.

OK, quick update. I "fixed" the EFIS plug Sunday. Although, I am wondering if I even needed to. The wire in question is the ARINC output going back into the EFIS. Since I am only using the ARINC to feed data to my autopilot, I'm not even sure at this point that the return wire is necessary. It seems like my use of the ARINC would be a 1-way task...EFIS>ARINC>A/P!??

So I spoke with GRT again today to update them and ask the next set of questions. During the conversation, GRT felt like my ARINC was actually now working (to be honest, it was probably working all along). It was the ARINC missing data message that made me think I have a problem. But at the end of the day, warning messages aside, it is my A/P that is actually leading me to believe I have an ARINC issue. The warning message may just be a red herring. When I turn the A/P on it tries to bank the plane (right I believe), and try to dive. At that point, I have to turn it back off.

Here is where I am grasping at straws. I cannot figure out what the A/P is responding to. I thought that maybe the EFIS was controlling the A/P, whereas pre-ARINC install, I controlled the A/P through the A/P. I'm just not GRT savvy enough to use the EFIS to intentionally control the A/P.

Here is why I agree that the ARINC has probably been working all along. Prior to install, the A/P would turn on in track and altitude hold mode. That is it would maintain current steady-state flight. Then, if I wanted to follow a flight plan, I could toggle to the next level of capability,which was GPS NAV. NOW, the A/P turns on in GPSS mode, which is loosely the same as an "enhanced" GPS NAV mode. So, again, ARINC warning message aside, My true problem seems to be I don't know why the A/P is functioning the way it is. GRT seemed to tell me the A/P control head would not fight with the EFIS for control of the actual A/P.

One last thing. GRT feels convinced that I have an old EFIS software version. This is why they thought I should be able to tell the EFIS which port the ARINC was on. I am going to check that tonight and make sure I can remove that from the equation. But it's difficult to believe the software would cause the rest of the issue(s).

I apologize if someone has given me the answer already in this thread. I am learning this all as I go, so some suggestions may not be obvious yet.

Do this make any sense to anyone?

Thanks! Andy

Well, one data point. I installed a Trio Pro and GRT HX well before (like 10 months prior to) first flight. The Trio worked in'stand-alone' mode, but went into a divergent vertical oscillation when controlled thru the HX. After a lot of back and forth, Trio realized I had older software installed. An autopilot software update fixed all problems.

BobTurner said:

Well, one data point. I installed a Trio Pro and GRT HX well before (like 10 months prior to) first flight. The Trio worked in'stand-alone' mode, but went into a divergent vertical oscillation when controlled thru the HX. After a lot of back and forth, Trio realized I had older software installed. An autopilot software update fixed all problems.

Click to expand...

That's hopeful!!!

If it's the EFIS software it's easy to check. Boot it up, go to the main menu, and write down the software version number. Go to the GRT web site, software, and see what the current version is. If yours is old follow the instructions to download the latest version to a memory stick, and from there to your EFIS. For my Trio autopilot, it was harder - I had to send it back for a firmware update.

I have a boatload of pics of all the important screen in the efis, including the boot. I'll have to send them to my phone so I have them handy. I'm pretty sure I updated everything when I bought the plane but we'll see tonight.

I'm also going to have to learn how to use the EFIS to control the A/P but that should be pretty easy from the manual. Funny thing, I used to feel around behind the EFIS to locate the USB slot. I've had the EFIS out or been under or behind the panel so much with this issue, I ordered and installed a USB cable.

I have the current software version, so we can cross that off the list.

I actually went back and read your posts. I had presumed the gps source was something like a 430 or GTN 650 etc. I see that assumption is wrong.
I am not sure that the internal gps units in either a GRT or Garmin EFIS can issue GPSS commands. These are direct steering commands to an autopilot or FD.

Try this: on the autopilot, turn GPSS commands OFF (again, whatever is needed. My Trio does it automatically, but I think the TruTraks need a specific on/off). Center the heading bug on the efis heading tape. On the GRT EFIS autopilot menu, enter the current altitude as the desired one, select "heading" on the GRT autopilot menu; engage the autopilot. How does that work? Use the left EFIS knob to move the heading bug. Does the autopilot follow it (turn)? If okay, try changing heading to ENAV in the autopilot menu (GNAV only works with GPSS commands). See if it intercepts and follows whatever GPS course you have (previously) entered.

I'll try that this weekend Bob if I get back to the plane. I am virtually certain the internal GPS can send the GPSS data as long as I have the optional ARINC installed. That's why I paid the $500 bucks for it. I am supposed to be able to control the Gemini A/P from the EFIS with the ARINC module. I should also be able to fly a HITS approach to any runway in the EFIS database. I figured it would be a good safety tool if I ever got irresponsible and caught in IMC.

That really is the last thing I can try. I read through the A/P section of the GRT manual. So once I make sure the EFIS isn't confusing the A/P in some way that I may have inadvertently told it to, I am out of options. Thanks for sticking around!!

One last question: If you totally disconnect the autopilot from the EFIS, will it at least attempt to maintain straight and level when turned on? I think it should.

It was always the EFIS driving the A/P, now it still is, but through the ARINC module. I would have to pull pins from the A/P plug to test it. If we are trying to see if the A/P works, that IS a question mark. It worked while attached to the EFIS without the ARINC. But the airspeed tape was off. It read 49 knots in the hangar. So I sent it back to Trutrak. I just can't remember if installed the ARINC while I still had the functioning A/P in the plane.

I'd suggest putting in a "stand alone" switch. If things go really wrong (e.g., dark or IMC and EFIS dies) it might be nice to just be able to fly straight and level.

But to your issue: Do I understand that everything (EFIS, autopilot) worked okay before you installed the ARINC wires? Since you found one wiring error, did you triple check the others? You should have ARINC A OUT from the EFIS to ARINC A IN on the Trutrak, and ARINC B OUT from EFIS to ARINC B IN on the Trutrak.

BobTurner said:

I'd suggest putting in a "stand alone" switch. If things go really wrong (e.g., dark or IMC and EFIS dies) it might be nice to just be able to fly straight and level.

But to your issue: Do I understand that everything (EFIS, autopilot) worked okay before you installed the ARINC wires? Since you found one wiring error, did you triple check the others? You should have ARINC A OUT from the EFIS to ARINC A IN on the Trutrak, and ARINC B OUT from EFIS to ARINC B IN on the Trutrak.

Click to expand...

I may have a stand alone switch. I have some type of toggle between my two GPS sources (GRT and G3X (moving map only)). As I understand it, the switch allows me to direct one source over the other to the A/P for things like flying a flight plan. I can't say how it is intended to work though given the fact that the G3X is external to the EFIS. I know you can define a GPS2 in the EFIS, but I have never played around with that because the wing leveler that was originally in the plane never worked. But my point is, someone put some thought into this set-up when it was built. I think Stein was involved in the original panel to a certain degree. I remember seeing some instructions from him about how to set-up the equipment that he sold the builder.

BobTurner said:

But to your issue: Do I understand that everything (EFIS, autopilot) worked okay before you installed the ARINC wires?

Click to expand...

Sort of. When I had the A/P installed where the old wing leveler was, Saint Aviation prewired the ARINC connections into the harness. Then, the plugs were tied off out of the way. SO, the A/P worked perfectly with the EFIS while the ARINC module was not installed, and the plugs for it sat idle off to the side.

After deciding that it was worth having the ARINC installed, I bought one and plugged it in. I turned the ARINC Installed? option in the General Setup menu of the EFIS to "Y." At that point, the "problems" began. I immediately began getting the ARINC data warnings, AND the A/P would not behave in what to me seemed like a rational way.

I'm pretty sure the plugs added to the harness for the ARINC installation are correct with the exception of the one I made correct after the fact.

I think I need to absorb some of this for a while. One thing that still bothers me is GRT is really clinging to a need to point the EFIS to the ARINC module on serial port 4. The believe the EFIS software version was old and the option to direct the EFIS to a particular port to look for the ARINC was missing in the old software. But this is not the case though as I have the current software. But they keep bringing this up so it seems significant.

I think I have an easier way to test the A/P. That is to unplug the ARINC and turn off the option in the EFIS. In theory, I should be back to a working A/P like I had before I attempted to add the ARINC.

Andy,

You originally stated you have an early GRT Sport. It likely has a built in GRT GPS, usually connected to Serial port 3.

Like Bob, I also didn't understand your set up. There is no GNS 430 or GTN 650 or similar GPS navigator, correct? Your G3X is not one either.

You will have to follow your wiring. I would check with Stein if they originally made the panel or Jesse's crew may have made a wiring diagram. The switch may indeed allow you to select either the GRT GPS or G3X GPS to send RS232 GPS information to your autopilot. This will provide horizontal steering only, no vertical steering and no GPSS steering.

I have older Sports also and ARINC, but no autopilot. My ARINC is connected to serial port 4 of my primary Sport. However, in General Setup page, serial port 4 in and out are set to OFF since I am not using the serial port 4 provided on the ARINC module. I think GRT tech support may be mistaken here. The ARINC module connects to the Sport over the Sport serial port 4. Since that makes that port unavailable for other uses, GRT added a serial port to the ARINC module to replace the one the module took away from the EFIS. If you use the "extension port", you have to tell (define) it's use to the EFIS just like any other port. But you aren't using it, so your Serial Port 4 in and out should be OFF. This has been standard in the software for years.

Bob is the autopilot expert, certainly not me! But, does your autopilot work correctly by itself? Meaning just using it's front panel controls? Then if you connect just the RS232 signal, does the EFIS control it properly? This should be how you have been using it until now. Can you use the switch and control the autopilot with the G3X?

GRT Sport EFIS require an upgrade to support vertical autopilot commands. Do you have this?

You might want to put your thoughts together and the results of your investigation and post it on the GRT Community Forums. GRT's Jeff, who does all the software programming monitors that forum and provides answers. He is probably the most qualified person to assist.

Keep us posted!

Jim Butcher

Hi Jim. Here are some responses. Thanks!

h&jeuropa said:

Andy,

You originally stated you have an early GRT Sport. It likely has a built in GRT GPS, usually connected to Serial port 3. Yes, and it is

Like Bob, I also didn't understand your set up. There is no GNS 430 or GTN 650 or similar GPS navigator, correct? Your G3X is not one either. I'm not sure about this. It is a moving map GPS with flight planning capabilities. It just does not have AHARS or ADAHRS. So it can't be used as a PFD but it is as much of a moving map as the internal GPS on the GRT EFIS

You will have to follow your wiring. I would check with Stein if they originally made the panel or Jesse's crew may have made a wiring diagram. The switch may indeed allow you to select either the GRT GPS or G3X GPS to send RS232 GPS information to your autopilot. This will provide horizontal steering only, no vertical steering and no GPSS steering. I could look for the Stein information but there wasn't any harness info. It was just a page of instructions for connecting the equipment the builder purchased. I don't think it even went as far as the individual pin and plug level of detail.

I'll take you word for on the steering because I can't refute it. BUT using the A/P control head before I injected the ARINC into the equation, the A/P would fly GPS NAV of my flight plan in the GRT EFIS, and I was also able to specify through the A/P a preset altitude to climb or descend to, and at what rate of climb or descent. I guess that was the A/P capability aside from the information the EFIS was sending to the A/P. And yes, I believe the toggle switch was simply allowing me to independently decide which flight plan I wanted to send to the A/P. That is, the GRT plan, or the G3X plan.

I have older Sports also and ARINC, but no autopilot. My ARINC is connected to serial port 4 of my primary Sport. However, in General Setup page, serial port 4 in and out are set to OFF since I am not using the serial port 4 provided on the ARINC module. I think GRT tech support may be mistaken here. The ARINC module connects to the Sport over the Sport serial port 4. Since that makes that port unavailable for other uses, GRT added a serial port to the ARINC module to replace the one the module took away from the EFIS. If you use the "extension port", you have to tell (define) it's use to the EFIS just like any other port. But you aren't using it, so your Serial Port 4 in and out should be OFF. This has been standard in the software for years. This is my understanding and exact setup as well.

Bob is the autopilot expert, certainly not me! But, does your autopilot work correctly by itself? Meaning just using it's front panel controls? Then if you connect just the RS232 signal, does the EFIS control it properly? This should be how you have been using it until now. When I got the A/P installed, I flew it using the A/P controls themselves. It would let me hold a course, climb and descend, and use control wheel steering (That is, turn deviate from the selected course by turning the knob on the A/P. I could also move past that initial control level (which you get when you turn the A/P ON) and turn on the GPS NAV mode which would fly the flight plan in the EFIS. I never tried to actually control the A/P directly from the EFIS menus. Can you use the switch and control the autopilot with the G3X? I believe I tested this successfully but I've tried to keep the G3X out of the discussion because I figured that just complicating things. If the EFIS and GPS and ARINC all work, I can worry about the G3X working later.

GRT Sport EFIS require an upgrade to support vertical autopilot commands. Do you have this? I don't believe I do. I never did the upgrade. So, like the G3X, I figure I can worry about that later (unless it might be part of the current problem!!)

You might want to put your thoughts together and the results of your investigation and post it on the GRT Community Forums. GRT's Jeff, who does all the software programming monitors that forum and provides answers. He is probably the most qualified person to assist. I may try this but it seems like I just have some type of novice issue that is a simple oversight. Maybe it is more sinister than that, but I just seems like it should be a simpler problem.

Keep us posted!

Jim Butcher

Click to expand...

OK Jim, some of this is sinking in now. I guess by navigator, you me a radio or similar than can fly an approach using the autopilot. No, I do not have anything like that in my plane.

I think I need to go back and start at the A/P end of the chain now to confirm that the A/P is actually working. I presume now that it uses its own gyro and pitot/static input to control the pitch and roll servos. It just can't fly a course line, only a heading. And all vertical commands are simply based on current altitude and rate of change. I'm not sure why it took so long for me to separate the EFIS and the A/P in my head. I'll be back with some info in a few days I hope.

Andy,

Yes. A navigator like GNS430 not only has a GPS but it has in it's memory all the approaches. So when you select an approach, it "knows" all the points (fixes) and altitudes. It is having all these brains that make them so expensive!

Which TruTrack do you have, Gemini AP?

Did Jesse do the AP install? If so, he probably knows how things are wired, especially "the switch".

I think your explanation of how your autopilot works is correct. The only thing to add is that it probably can follow a flight plan. It just will not have turn anticipation - it will fly to a point in the flight plan and then turn to the next point. Turn anticipation smooths those turns by starting them before you actually get to the point.

Why did you decide to add the ARINC capability? Were you looking for vertical autopilot modes?

I don't know how to tell if your Sport has the vertical autopilot software. Ask GRT Tech support.

I think you're making progress. Welecome to experimental aviation

Jim

OK guys, I'm back.

I think everything works now. I appreciate all the patience and help from you guys!!

I went to the hangar today to step back, and test each piece of equipment in the chain, beginning with the A/P itself. I removed the three wires from the A/P that were associated with the EFIS (RS232 for the internal GRT GPS, and the 2 ARINC wires). Then I flew the plane and tested the A/P alone. It worked. Then I added back the internal EFIS GPS and flight tested that. It worked. Then I added back the 2 ARINC wires and flight tested that. Fortunately, things worked this time. And to cut to the chase, what I think the problem was, aside from the 1 misplaced wire from before, was a baud rate setting mismatch between the GPS on serial port 3, and the A/P. Hard to believe...

To make a long story short, I feel like I learned a ton about the system and how it functions. FAR more than I cared to in the beginning. But looking back now, it seems like I would have been spoiled if it all worked when I plugged the ARINC in the first time. This was some sort of right of passage I guess.

Now I have to go and learn how to use the new equipment.

Thanks again for all the help!! Andy

PS. I did my 1st Pilots n Paws trip Saturday. Flew from NJ to NC and back to bring Krypton to a doctor to get him help with a really bad spinal issue. He was a happy dog! I could have used the A/P!!

GRT Sport SX Serial Port 4 Setting for ARINC Module

I'm running into similar problems with my GRT Sport SX not controlling the auto pilot.

The system was working fine, but when I sent the Sport back to GRT to fix the screen the unit came back and this feature no longer works.

Configuration:
- Single GRT Sport SX
- GRT ARINC 429 External Module
- Garmin GNS-420W
- Trutrak Vision 385


Question:
In the GRT EFIS Settings and Values, what do I set the the "Serial Port 4 Input" and "Serial Port 4 Output" to?

Note:
I have "ARINC Module Connected | Yes"

Thank you in advance.

VIN2020 said:

I'm running into similar problems with my GRT Sport SX not controlling the auto pilot.

The system was working fine, but when I sent the Sport back to GRT to fix the screen the unit came back and this feature no longer works.

Configuration:
- Single GRT Sport SX
- GRT ARINC 429 External Module
- Garmin GNS-420W
- Trutrak Vision 385


Question:
In the GRT EFIS Settings and Values, what do I set the the "Serial Port 4 Input" and "Serial Port 4 Output" to?

Note:
I have "ARINC Module Connected | Yes"

Thank you in advance.

Click to expand...

I believe that GRT sells that as an option on the sport series. It is turned on or off via s/w config at that factory. I am guessing that they may have forgot to turn it back on after a s/w reload or factory reset.

Larry