AdvancedHMI Software

General Category => Open Discussion => Topic started by: iDeeW on February 09, 2017, 01:03:53 PM

Title: Datalogger2 missing seconds!
Post by: iDeeW on February 09, 2017, 01:03:53 PM

Hi,
I ran the Datalogger2 control for 4 hours in parallel with a Yokogawa chart recorder. 
When I compare the two files I saw there are 283 seconds (4.72 minutes) missing on the log file from Datalogger2 control......!
Missing seconds are randomly distributed through out the 4 hour period.
Any ides why this happens?

Thanks

Title: Re: Datalogger2 missing seconds!
Post by: Archie on February 09, 2017, 06:04:19 PM

The DataLogger runs on a Windows timer which is not deterministic, so the time between samples will experience jitter, especially if you are running any other software on the PC.

You can get better repeatability by using a DataSubscriber, writing the data via code with the DataReturned event, and using the driver's PollRateOverride to regulate the sample period. This is because the driver runs on a background thread and is more repeatable.