ArcPad sporadically loses AXF saves when map is closed

[TravisBugg1]

We have several field crews out recording data using ArcPad 10.2 and Trimble 3B units with an AXF and custom forms. The forms were modified in ArcPad Studio, and differ mostly in formatting from the forms automatically generated from the geodatabase. The GDB does contain several domains that are used in the forms. We've also been using the Add XYZ applet found on the ArcScripts webpage.

One unit in particular is giving us problems. Twice in the past two field sessions, the user collected data throughout the day, and then closed the map when heading out of the field. Upon returning to the hotel room to back up the data, they realized that all of the day's data was simply gone. Missing. The previous day's data was still there, but everything from that day ceased to exist.

Throughout the day, the points, lines, and polygons recorded were visible on the map, so you'd think they were saved and quite safe, but evidently that was not the case. The first time this happened, all of the day's data was lost, except for the first point taken that day. The second time it happened, all data recorded that day was lost.

Does anyone have any idea what may cause ArcPad to not retain saves to an AXF when closing the map? As I understand it, changes to the AXF should be saved automatically once the forms are "OK'd" and exited from. The fact that this has only happened on one unit, makes me wonder if it is a hardware problem, but if data corruption is happening on a hardware level, that doesn't explain why only select data from one day at a time is being lost. My second thought is that perhaps the installation of ArcPad itself if corrupt.

I'll post with any solutions or insights I come up with once I have the unit in hand, and can perform tests on it myself. Until then, I welcome any experience, workarounds, explanations, or thoughts concerning what may be happening here.

Thanks.

[RebeccaStrauch__GISP]

Travis, are you writing data periodically throughout the data to file (e.g. after each form)?  I used to have issues with losing some data after collecting for an extended period of time.  My solution was to write to the physical file more often, otherwise I believe much of it was stored in memory.  For our project, I had logical places in collection that who save (without user intervention).

This was a v6.1 thru 7.1 project....which I will be updating to 10.x soon....so not sure if things will be different in 10.x, but I think writing more often will still work for my project.

[TravisBugg1]

Thanks, Rebecca. I forgot to add that I was on ArcPad 10.2. I edited the post to reflect that. As to your question, I don't believe any other data is being written outside of the forms. I'll look into it, though, and make sure. Perhaps I can add an auto-save function to make sure the data is being written to the device storage after every feature capture (I thought it did that by default, but I could be wrong).

[IngridHogle]

Did you try exporting features from the AXF to a shapefile via ArcPad Studio, to see if the data were actually saved in the AXF but are just not checking in? We have to do this about once a month, it seems, when something inexplicable goes wrong with an AXF. To date, the data have always been retrievable this way. We have sometimes been able to fix the problem by doing a reinstall of ArcPad on the desktop computer used to make the checkouts, as often the issue is something that goes wrong during the checkout process.

[TravisBugg1]

Hi Ingrid,

When the user closes the map, and the day's data is lost. It is totally gone. As if it had never existed. There is nothing to check in, and when exported from ArcPad Studio to a shapefile, that data still isn't present. I've even opened the AXF in Microsoft SQL Server Management Studio Express and I can see records and repair the underlying database, but the data is nowhere to be seen. Puzzling indeed.

The data has been observed as missing before the AXF is even transferred from the unit. The two times this has happened the user closed the map, and then re-opened the map later. All, or practically all, of the data for that day was gone. The data was viewable on the screen and in the attribute table previously, but when the map was re-opened, it was no longer there.

I have used the export to shapefile function with great success in the past, but this time it's a no go. It's almost as if the changes made and features created are being stored in volatile memory and are not saving back to the AXF in the device storage. When the program is closed that volatile memory (RAM) is dumped. That is just a theory, though, and it goes against my conception of how ArcPad works. I was always under the impression that GPS captures and form attributes were saved to the AXF immediately.

Thanks for your input.

[IngridHogle]

Super bummer. I'd try a reinstall of ArcPad on the checkout computer and see if future checkouts have the same problem. And definitely open a case with Esri Support. I hope we never experience this problem, but I'd like to know what is going on so we can avoid it!

[NICOLAPEDDIS]

If the problem persist you need to reinstall arcpad in the PC and in the GPS device. In the most of cases is due to the absence of the Microsoft SQL Server Compact Edition 3.0 o 3.1. This tool is necessary to the program to write correctly the axf files. Check if is present in the PC and in the GPS device.

[TravisBugg1]

Thanks, Nicola. That's a good idea. I'll try that and let you know if it works. However, I'd think if MS SQL Server Compact wasn't installed, ArcPad wouldn't be able to write to the AXF at all. This problem has been unpredictable and sporadic. I suppose the SQL Server Compact installation could be corrupt, however, leading to odd and inconsistent behavior...

Thanks!

[AlanKilgore]

I've had data apparently disappear because I had a filter set  on my layer definition.  If new data did not meet the definition query it did not show up in ArcPad.  In my case, I changed the layer definition in ArcPad Studio to remove portions of the query that were preventing the data display,  I was then able to see the data I had collected.