I asked in the LabView and SignalExpress forums if there is
a way to time stamp each fetch to account for clock drift without any
luck.
http://forums.ni.com/ni/board/message?board.id=380&thread.id=1548
http://forums.ni.com/ni/board/message?board.id=170&message.id=431722&query.id=494967#M431722
I’m using fetch (size) in reference to the fetch size in the
niScope Stream to Disk Queues Win32 File IO VI.
I normally set fetch size to 512000 so ideally I’d like a GPS time stamp
for each 512000 sample set.
Is it possible to do the following:
1.
Set the Time Reference to GPS in the test panel
for the 6682 in MAX.
2.
Under the TimeStamp tab choose an input terminal
that corresponds to each fetch with the trigger type set to ‘Continuous’.
3.
Start the TimeStamp process.
4.
Start collecting data with the Win 32 File
IO.vi.
I’m hoping that there will be GPS timestamp associated with
each fetch.
I have a few questions with this approach.
1.
Is it workable?
2.
Is there a way to copy timestamps listed? When I right click, choose ‘copy data’, and
try to paste in notepad, nothing is copied.
3.
Would there still be some software latency so
that the timestamp is not synchronized with either the start or stop or the
data set.
Another solution would be to get a acquisition start
timestamp (I can do this using the Time Stamp Trigger VI) and an acquisition end
time stamp. I’m not sure how to get end
of acquisition time stamp.
I’m new to LabView and NI instrumentation so I apologize if
these are naïve questions. Thanks.
