We are having problems with clock on the specified setup. Throughout using T20 we’ve had some issues but most of them were resolved by different quickfixes done in our software on the board. However, latest problem started after removing RTCSync.exe over a year ago. We removed it because we noticed that it was slowing down windows reboots, making them take up to minutes instead of seconds. We resolved to reading the time from RTC ourselves and syncronizing it
So right now I’ve done many tests with T20 with its clock and the last discovery is as follows: When board boots up, every 24 hours it starts moves its clock backwards by around 20 seconds. This isn’t a single board that is behaving as such but we currently have 19 with running tests, all behaving the same. So it is very clear that some software is tinkering with it. I doubt that any RTC in the world would do such a thing? It’s still possible that our software is doing it, but I’ve removed all parts I can find the WinAPI SetSystemTime/SetLocalTime in our software.
So my question is: Do You know what could be causing this? We’ve been under the impression that RTCSync.exe is the only thing that does anything with the clock, but is there another process in the image that is doing some offset-fixing?
How did I reproduce this:
- Removed any possible part where our software might do anything with the clock
- Disabled RTCSync.exe from registry and reboot substation.
- Every 5 minutes Our own application checks time from an NTP server, but doesn’t set the time
- Application counts the difference in seconds and reports it
Here are few lines from our log, where way calculation is NTP servertime minus T20 GetSystemTime difference in seconds. Device was rebooted around 4.2.2019 9:16:00 and offset started at -68 seconds.
05.02.2019 09:15:06 SNTP time update from server Ok Offset was -66.5158 sec, (Stratum=2) 05.02.2019 09:20:07 SNTP time update from server Ok Offset was -82.0391 sec, (Stratum=2) 06.02.2019 09:15:22 SNTP time update from server Ok Offset was -81.1062 sec, (Stratum=2) 06.02.2019 09:20:23 SNTP time update from server Ok Offset was -101.3768 sec, (Stratum=2) 07.02.2019 09:15:43 SNTP time update from server Ok Offset was -100.4333 sec, (Stratum=2) 07.02.2019 09:20:44 SNTP time update from server Ok Offset was -120.6950 sec, (Stratum=2)
I would be very grateful on any information on this. Debugging this is slow as it takes 24 hours for this to happen. This also makes calibrating RTC hard when every time this happens, it is also set to RTC, so I cannot go around this in any way.
Thank you in advance!