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GRT Engine Data Issue--Looking for Advice

tom_AZ

Well Known Member
Background--I have a GRT Sport SX and EIS6000. Typically, I'll pull the USB stick from the EFIS after 2-3 flights and download it to a laptop harddrive--either for submission to Savvy for analysis, or just to retain in case a problem of some sort were to arise and I want to look retroactively for when it might have begun.

The GRT stores two types of files. One is an Excel CSV file, named GRT Flight Data Log. I've not used that. It always seems to be about 30 MB in size, so I assume those 30 MB are the "last data", and anything earlier is overwritten--but I don't know that with certainty.

The other filetype is a text document. Those filenames start with DEMO, then the date, then a five digit number. Those files aren't much larger than 15 MB, which is limited by the amount of memory in the unit. When that filesize is reached, it writes to the memory stick, and starts a new file with the same name, and a +1, +2, +n... extension. For Savvy analyses, the DEMO files are zipped together and submitted.

I recently pulled the memory stick to download the latest files. The CSV file was there for the most recent flight, but there were no recent DEMO files. I removed and reinserted the USB stick, even though given that the CSV file was present, a poor connection there seemed unlikely. Also, the 1 GB memory stick is slightly less than half full, so it's not a capacity issue.

I contacted GRT, who have always been very helpful. They (Jeff) suggested it was a settings issue. Seemed unlikely, as I hadn't changed anything--although I had updated the NAV database. Nevertheless, I checked the settings menu, took a screenshot of that (attached), and sent it to GRT. It's set to automatically start recording as I exceed 40 KIAS, then stop when I've decelerated through 35 KIAS. Jeff replied that my settings looked OK, and that basically he had no additional ideas why the DEMO files weren't being written.

Has anyone experienced a similar issue, or have ideas on a cause and corrective action? I spoke with a hangar neighbor this AM who suggested re-loading the system software (after confirming that I have good records of settings of course). Before doing that, I thought I'd check with others who have GRT avionics to get their thoughts/suggestions.

Thanks in advance.
 

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Trouble shooting rule #1: Always try easy stuff first, even if unlikely. I’d try the download again, with a different memory stick. Preferably the one that came with the efis.
 
Thanks Bob

Trouble shooting rule #1: Always try easy stuff first, even if unlikely. I’d try the download again, with a different memory stick. Preferably the one that came with the efis.

Thanks Bob. There is no download to retry unless I'm missing something. The EFIS writes to the stick (or should), then begins collecting the next dataset. The memory in the EFIS itself is volatile as I understand it--shutting down the EFIS effectively erases it. Memory stick is unchanged, but it's clearly "working", as the CSV file is "new" each flight.
 
Yes, I meant on a short flight. I doubt it's the problem, but an easy test. Otherwise, it's not obvious to me what the issue may be.
Edit: PS In he past, I have used Excel to look at the CSV files, if that's of interest to you.
 
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Serial connection?

This may be a dumb question... but is the EIS6000 data displaying on the Sport SX? Perhaps you normally view it on the EIS only; in any case if the serial link between the EIS and the EFIS has failed then this could be a cause.
 
Something you might try, as a diagnostic, is to manually start and stop recording the Demo file rather than relying on airspeed. Just let it record for a few seconds and then stop the recording - no flights neccessary nor engine running needed. At least it will let you know that you're still able to write Demo files.

Regards,
Rob
 
I have Sport SX and EIS4000. It is my understanding DEMO files are such you can replay the flight on the SPORT SX and see speed, altitude, heading changes … flying sitting still per looking at EFIS. The CSV is what loads to Savvy. There is a setting to turn off Demo files. I see a message when the DEMO file is written to ubs drive in panel. I delete them from my thumb drive, upload all other files to SAVVY.
 
Page 139 in Sport manual describes these features.

Under Set Menu/ General Setup are the settings page

I would change from airspeed start and stop to RPM start and stop. This way you capture startup to shutdown. Your setup using airspeed MISSES capturing your run up, and all engine data until you are flying….you miss takeoff data capture, which i consider valuable.

FYI, this change makes no real noticeable storage volume difference. I would set USB FDL ALWAYS RECORD: YES.

I’ll see if I can’t get to hangar today and take pic of my settings

Good luck
 
Yes, I meant on a short flight. I doubt it's the problem, but an easy test. Otherwise, it's not obvious to me what the issue may be.
Edit: PS In he past, I have used Excel to look at the CSV files, if that's of interest to you.

Thanks. I need to look more closely at options for saving the CSV data. As currently configured, it would seem that mine saves to a single filename, and is size limited. Between the two of those, I would lose data on long flights, and would also lose data if I made a second flight without having downloaded the previous one. Time to look at that settings menu more closely.

Do you know if Savvy can use the CSV files in their analyses programs?
 
EIS Data Display on the EFIS

This may be a dumb question... but is the EIS6000 data displaying on the Sport SX? Perhaps you normally view it on the EIS only; in any case if the serial link between the EIS and the EFIS has failed then this could be a cause.

Good thought, but yes, engine data, etc... are displaying properly on the EFIS.
 
DEMO file writing test

Something you might try, as a diagnostic, is to manually start and stop recording the Demo file rather than relying on airspeed. Just let it record for a few seconds and then stop the recording - no flights neccessary nor engine running needed. At least it will let you know that you're still able to write Demo files.

Regards,
Rob

Great idea...not sure why I didn't think of that. I'll try it later today.
 
Thanks. I need to look more closely at options for saving the CSV data. As currently configured, it would seem that mine saves to a single filename, and is size limited. Between the two of those, I would lose data on long flights, and would also lose data if I made a second flight without having downloaded the previous one. Time to look at that settings menu more closely.

Do you know if Savvy can use the CSV files in their analyses programs?

From my grt equipment only csv files are used with savvy. I keep a usb drive loaded, no internal storage used, and no flight is too big for a single file , engine start to shutdown, 3-4 hours. CSV files are pretty compact. Ive never used a DEMO for anything, delete them all from my usb, upload remaining (csv files) to Savvy.
 
Action Plan

Thanks to all for great input and suggestions! I think I have an action plan for my next trip to the hangar...

1) Deactivate the "auto start/stop" setting for DEMO files, and attempt to manually record a DEMO file from the EFIS (engine off). If one is written to the memory stick, I still wouldn't understand why the automatic record feature isn't working, but as pointed out would at least know the software is capable of writing such a file. If I can't record one, I haven't solved the issue, but the location of the problem is narrowed.

Either way, after a settings backup (and confirmation that THAT wrote to the stick), it MIGHT be worthwhile to consider reloading software, but my ultimate solution may be an alternate approach.

2) It would seem that I've misunderstood how the CSV file works. I thought the file was restarted for each flight, but apparently it's simply appending new info on the end of the file. I've been sending multiple DEMO files to Savvy, but sending CSV files may actually be better, as they apparently contain all of the engine data, and data lost during the write to the stick process should be eliminated. I don't really use (or need) the other info in the DEMO files, e.g. location, etc... If for some reason I want to play back a flight path, ADS-B data are readily (too readily?) available.

I'll plan to change the settings for the CSV file type from "single" to "new file on each boot". That would seem to create a single file for each "flight", which would be best anyway.

Thanks too for the link to the software that can be sued for "user analyses". That looks to have been a HUGE amount of work to develop--hat's off! If I get the DEMO download issue resolved, it might be fun to play with.
 
From my grt equipment only csv files are used with savvy. I keep a usb drive loaded, no internal storage used, and no flight is too big for a single file , engine start to shutdown, 3-4 hours. CSV files are pretty compact. Ive never used a DEMO for anything, delete them all from my usb, upload remaining (csv files) to Savvy.

Exactly the same for me. I believe that Savvy can handle the LOG files, but I have only tried it a few times by accident. I should probably look again, but currently only upload the CSV files.

Emarit's tool is awesome, but takes some time to set up, and works in Windows, not Mac, so I generally only use the Savvy.

This is from the GRT documentation I have:

USB Flight Data Logger (Black Box Feature)

The USB Flight Data Logger feature was designed to provide automatic recording of a limited number of important flight data parameters. The data is saved within the EFIS and then periodically written to the USB drive according to user settings.

Go to SET MENU > General Setup > Demo Settings. Press the knob to open the page and bring up the following settings:

• USB Flight Data Logger: (ON/OFF) When ON, the EFIS will record data when any of these are true: airspeed is valid (above the sensor minimum), ground speed is above 5 knots, RPM/N1 input is non-zero, fuel flow is non-zero.

• USB FDL Record Interval (ms): Data samples are recorded within the EFIS at this interval: 200-30000 ms in steps of 200 ms. Default is 1000 ms (1000 ms = 1 second).

• USB FDL Save Interval (s): The recorded data is written to the USB flash drive at this interval: 0-300 seconds. Default is 60 seconds (if set to zero, the file is only written when the internal buffer fills up or the data logger stops).

The data is saved as a .CSV (comma separated variable) file on the USB stick called GRT Flight Data Log.csv and can be opened using any spreadsheet program.
 
Alternate start/stop limits

Page 139 in Sport manual describes these features.

Under Set Menu/ General Setup are the settings page

I would change from airspeed start and stop to RPM start and stop. This way you capture startup to shutdown. Your setup using airspeed MISSES capturing your run up, and all engine data until you are flying….you miss takeoff data capture, which i consider valuable.

FYI, this change makes no real noticeable storage volume difference. I would set USB FDL ALWAYS RECORD: YES.

I’ll see if I can’t get to hangar today and take pic of my settings

Good luck



I neglected to include this in my previous reply/plan. I agree that takeoff data are valuable, but starting at 40 KIAS has seemed adequate although it does miss the runup and the "power up" for TO. My concern about using RPM as start/stop triggers is that I would lose a variable amount of data toward the end of each flight. If RPM limits were set to zero (or other very low number), the last data captured (perhaps up to 30' or so) wouldn't be written to the USB unless I kept the EFIS alive through shutdown. As I understand GRT's recommendations, it's better to power the EFIS down along with other avionics prior to engine shutdown. My understanding is that the EFIS is somewhat spike tolerant, but not best practice to rely on that. If I had a b/u battery in the EFIS, I suppose that might keep the EFIS alive even though I'd shut off power from the bus, but I don't have that in my Sport SX system.
 
... As I understand GRT's recommendations, it's better to power the EFIS down along with other avionics prior to engine shutdown. My understanding is that the EFIS is somewhat spike tolerant, but not best practice to rely on that. If I had a b/u battery in the EFIS, I suppose that might keep the EFIS alive even though I'd shut off power from the bus, but I don't have that in my Sport SX system.

What are you concerned about causing a spike when shutting down the engine? I always thought the concern was at startup, since there is a huge current draw when engaging the starter.

The main change that I can think of in the electrical system when shutting down is that the alternator slows to a stop, but I have not heard that this might cause a change in the system that could bother the EFIS or any other 12v electrical component.
 
Spike?

What are you concerned about causing a spike when shutting down the engine? I always thought the concern was at startup, since there is a huge current draw when engaging the starter.

The main change that I can think of in the electrical system when shutting down is that the alternator slows to a stop, but I have not heard that this might cause a change in the system that could bother the EFIS or any other 12v electrical component.

I'm not a double E, and in fact am closer to the "electrons are basically magic" end of the spectrum, but at one point at least I was told that there can be a spike when the alternator field collapses. ...It might have been the same guy that told me to cycle the prop x3 and to never run the engine over-square so I'm ready to have my practice debunked, but pretty much every checklist that I recall has called for shutting down avionics prior to the engine.
 
My HX is configured to write to the USB every 15 secs. As long as I don't turn off the HX power until 15 secs after engine shut down then I can be assured of getting all the data. Mine is also set to write new files every time so I have a collection of time stamped files I can review. It's easy to distinguish the flights from the hangar power ups by the file size.
 
Update...

Thanks to all for great input and suggestions! I think I have an action plan for my next trip to the hangar...

1) Deactivate the "auto start/stop" setting for DEMO files, and attempt to manually record a DEMO file from the EFIS (engine off). If one is written to the memory stick, I still wouldn't understand why the automatic record feature isn't working, but as pointed out would at least know the software is capable of writing such a file. If I can't record one, I haven't solved the issue, but the location of the problem is narrowed.

Either way, after a settings backup (and confirmation that THAT wrote to the stick), it MIGHT be worthwhile to consider reloading software, but my ultimate solution may be an alternate approach.

2) It would seem that I've misunderstood how the CSV file works. I thought the file was restarted for each flight, but apparently it's simply appending new info on the end of the file. I've been sending multiple DEMO files to Savvy, but sending CSV files may actually be better, as they apparently contain all of the engine data, and data lost during the write to the stick process should be eliminated. I don't really use (or need) the other info in the DEMO files, e.g. location, etc... If for some reason I want to play back a flight path, ADS-B data are readily (too readily?) available.

I'll plan to change the settings for the CSV file type from "single" to "new file on each boot". That would seem to create a single file for each "flight", which would be best anyway.

Thanks too for the link to the software that can be sued for "user analyses". That looks to have been a HUGE amount of work to develop--hat's off! If I get the DEMO download issue resolved, it might be fun to play with.


1) I turned off auto start/stop, saved that, and rebooted. Powered back up, and did a "manual" DEMO record/stop. A DEMO file was written to the USB, so the capability is there, but for some reason the start/stop triggers weren't working. Also, I see that the DEMO file saved with a date of 1/1/2000 (or something like that). I was in the hangar, so no GPS signal. My guess is that the date is a default if no "date/time" is available from satellites. Can someone confirm or correct that assumption?

I confirmed settings for the flight data logger to be: on, record interval of 1000ms, and an FDL Save interval of 60s. I changed the USB FDL Always Record from no to yes. Checking the USB after a couple of minutes, there was a new FDL file. It too had a file date of 1/1/2000 (or similar), with 0000 as the filename. As above, I assume the date is a default. Is there a way to get the correct date into the filename (that would be valuable in terms of sorting out which file came from exactly which flight)?

Thanks again for all of the comments and suggestions received.
 
You are correct, the date and time come from GPS.

My old Sport only has DEMO capability which I find useful. I used to start recording with airspeed like you, but about a year ago I started manually controlling DEMO record and stop. My Rotax requires several minutes to get oil temperature high enough for ignition check. So today I wait until the temp is up, then start record so I have the run up data. After landing, I usually stop recording while taxiing to the hangar. This is working well for me.

Probably not a factor for you, but the USB port is on the rear and there is a cable that provides a jack for the USB drive on the panel. I've had a couple of those cables develop intermittent connections. I also use a physically tiny USB drive, as the weight and size of old large ones seemed to make the cables fail.

I've also had the display say Saving Demo and never complete. Often when that happens, the USB drive apparently has a bad connection. If I slide it out of the socket and back in, saving completes.

Jim Butcher
 
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