Posted Mon, 31 Jul 2023 09:06:07 GMT by Handrejch, Jan

Hello Kei/Tek team,

We have been using the DAQ6510 (fw. 1.7.12b) measurement instruments for our long-term measurements in combination with the 77xx MUX cards, depending on the type of measurement. However, we have encountered a persistent issue during data logging to a USB flash disk. After approximately 72 hours, sometimes sooner, sometimes later, the instrument becomes unresponsive. We are unable to control it, and even when switching between Front/Rear, the instrument does not respond. The buttons seem to work, but we cannot make any changes or stop the measurements, and the data logging process is stalled, presumably waiting for the write operation to the Flash disk. The only solution in this situation is to power off the instrument using the physical button. This error prevents us from using the DAQ6510 instruments standalone without an additional computer, and we are compelled to revert to using DAQ KEI270x.

I have attached several photos from the latest occurrence of the issue during a 10-channel 4W resistance measurement. The scan settings were as follows: 4Wres, NPLC = 4, 2 seconds between measurements, channels 101 to 110, Buffer = 100k, and data logging to the Flash disk after each scan. We used the 7708 MUX card for this "ordinary" resistance measurement. After approximately 47,594 measurement cycles, the instrument froze and stopped measuring further. Neither the "Abort scan" nor the "Pause scan" functions were effective in resolving this issue.

Additionally, I would like to mention that the USB flash drive used is a fresh new Verbatim 32GB, empty, and formatted as FAT32. It is important to note that this issue is not isolated to a single instance; it occurs frequently on all four of the DAQ instruments we have.

We kindly request your assistance in resolving this matter as it is significantly impacting our data acquisition process.

Thank you for your attention and support.

Best regards,
Jan Handrejch

Posted Wed, 02 Aug 2023 21:34:49 GMT by C, Andrea
We will need to dig into this one a bit.

Question:  if not logging to USB, would the long duration scan operate without any issue?  Do you have opinion about that?
Posted Tue, 08 Aug 2023 08:34:12 GMT by Handrejch, Jan

Hello,

I am currently testing logging without a USB flash disk, using only the internal buffer memory. The measurement is set up with the same parameters, and the logging process is running smoothly, with approximately 95k records logged over the course of approximately 5 days. Therefore, the DAQ appears to be functioning correctly under these conditions. I will continue to monitor its performance and will inform you of any potential issues.

Best regards,

Jan Handrejch

Posted Sun, 13 Aug 2023 12:11:43 GMT by C, Andrea
Hi Jan,
I wanted to let you know I did duplicate the stalled scan once.  But is very intermittent.
I have opened a bug report for it in our quality system.

For the csv files it does generate, if you compute the delta on the reported time of each scan, does it increase from the expected 2 seconds as the file accumulates rows?

Andrea
Posted Wed, 13 Sep 2023 10:36:36 GMT by Van Straaten, Michael
Hi,
I had the same problem in the last few weeks. We use the DAQ6510(fw1.7.12b) with the 7700 card and tried to measure just voltages.
During the first setup tests we monitored 13 Channels without a specified scan interval and ended up with a delta of 7.7s between scans. That scan ran successfully for roughly 16 days.<br> After that we tried to increase our time resolution and monitored only 2-6 channels with shorter or no channel delays and ran into the same problems as described by Jan.<br> It seems the shorter the scan interval gets the sooner the system freezes. For example with only 500ms scan interval the scan froze after 11h11min and with 800ms it lastet 15:34.
According to the .csv the reported time delta is stable around the set scan interval. It only switches between 3 distinct values: set scan interval, set +80ms and set -80ms. This is true for both 500ms and 800ms scan interval and does not change over time.
Last Friday I downgraded the firmware to 1.7.0e after seeing that in that version a similar issue (Reference number: AR62869, NS-1771) was resolved. Over the weekend a successfull measurement (800ms scan interval) ran for roughly 72hours without crashing and since then another was started that is still running (52h so far).
The delta between reported times looks similar to before with the majority of values beeing setpoint+-80ms, but within the first 16 hours there are now roughly 40 to 50 points that are slightly outside this pattern (see attached plots).
I hope this helps with resolving this problem

Edit: Over the last weekend we encountered again a failed measurement after 12h with the downgraded firmware, so sadly it doesn't seem to work. The only difference in the setup that I'm awate of, is that during the successfull tests I didn't set up the graph. While the failed run had two traces displayed with individual autoscale (y-axis) and show all readings (x-axis)

Kind regards
Michael
Posted Sat, 30 Sep 2023 12:00:28 GMT by C, Andrea

Hi Michael.  Great feedback!  I’ll make sure the factory/firmware engineers are aware of your report.

Posted Wed, 10 Jul 2024 09:24:11 GMT by Handrejch, Jan
Hello,
is there any new information about this "bug"? Has it been fixed or is it only a specific problem with our measurement setup?
Kind regards,
Jan

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