Does NI VeriStand manage Daylight Saving Time (DST) on RT target ?

[MaximeR]

Hello,

I want to know if VeriStand engine on RT target manage DST. I have a project with a CompactRIO 9076 that runs a NI VeriStand project at startup. This cRIO starts at 1/1/1970. I can change the date with a LabVIEW VI to set the date equals to the host computer. It works well but I don’t understand the time of the system. The cRIO doesn’t handle DST, but when I display time in a graph in the workspace, DST is applied to absolute time.

Does anyone have information about that?

I need more information, because I’m using the Embedded Data Logger Custom Device, and in the name of the file automatically created by VeriStand, the hours used to create the file didn’t take care of the DST, but the absolute time logged into the file have the DST applied. I want to remove this difference.

Thanks for your help.

MaximeR

[StephenB]

The data stream to the graph and the logged file datetime are in UTC time. The graph will adjust the viewed time automatically based upon your computers time settings. Also, the program you're using to view the timestamps in your data log is also automatically adjusting them based upon your computers time settings

you can confirm this by changing your computers time settings and restarting your log viewing program, then opening the same log again.

[MaximeR]

Ok. So it means that VeriStand add the DST based on the host computer configuration. Is there a way to block this functiaanlity in VeriStand with a token in NI VeriStand.ini ?

Thanks.

[StephenB · Accepted solution]

The workspace's waveform graph does indeed graph the time from the target, but then the host time zone settings are applied on top of the data to adjust it +/-

NI VeriStand does not adjust time at all. The adjustment you are seeing is by the viewing only. The data on the wire and in the log is always UTC, but the indicators or viewers you are using adjust it by the host computers settings.

[MaximeR]

Ok, Sorry, I changed my first reply., DO you have an idea if it's possible to set VeriStand to display only UTC Time ?

[StephenB]

Unfortunately there is no way to do this as it is a LabVIEW limitation.

http://digital.ni.com/public.nsf/allkb/ECA8521AA894ED6A862575D2006DCD04?OpenDocument

The workaround would be to change your computer to UTC time

[MaximeR]

Ok, thanks.

I finally understand the behavior for the date and time of the cRIO and VeriStand and the host computer.

Not so easy!

Thanks for the quick reply.

[StephenB]

I agree its not so easy. First time I saw this... I was very confused! I wish I could always view time in UTC as well.