Volt recording stops

[RTSLVU]

Well I have never used any of the Express VI's except for Time Delay so I am just guessing here but...

The Help for Write To Measurement File Express VI mentions writing data iteratively (like you are) and suggests setting the Flush to False (it defaults to True) until you are done.

Also this might be a stretch but I notice the logging stops at line 367001. Does it always stop there?

I wonder if this is a limitation of the Express VI's Excel file capability.

I remember back in the day Excel files were limited in number of rows that Excel could open.

Frankly it's time to ditch the Express VI's, IMHO: Express VI's were made specifically for those three hour LabVIEW programming seminars sales pitches. To show managers and other non-programmers how fast you can just throw something together... But they are too limited to be used in any actual applications. 

[Marinuss]

Thank you for your answer

I am currently using the DAC Assist Logging TAB to record to a TDMS file, so I did ditch the Express VI.

So now I see readings going to line 1048576 (about 3 hours worth of data) But this is Excel's limit I think.

So I need to open a new TDMS automatically when this point is reached. We need 24 hours of recordings.

Marinus

[GerdW]

Hi Marinuss,

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@Marinuss wrote:

I am currently using the DAC Assist Logging TAB to record to a TDMS file, so I did ditch the Express VI.

So now I see readings going to line 1048576 (about 3 hours worth of data) But this is Excel's limit I think.

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I guess you use the DAQAssistent to create your TDMS file.

Yes, those 2^20 rows is the Excel limit: there might be more rows in the datafile, but Excel cannot show them…

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@Marinuss wrote:

So I need to open a new TDMS automatically when this point is reached. We need 24 hours of recordings.

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This is the wrong conclusion: you need to use a different tool than Excel for data analysis!

The DAQAssistent will create your 24h TDMS files, even though I recommend to ditch it and use plain DAQmx functions instead.

But: when you want to create new TDMS files for the same DAQmx task run: this will not work! The TDMS filename is defined before you start the task, so to define a new filepath you need to stop and restart the task…

Suggestion:

• Use plain DAQmx functions to gain more control your your DAQmx data handling.
• Create larger TDMS files then just 3h.
• When your collegues can only use Excel then you provide another tool to view the large TDMS file, define a subset of the data and to convert that subset into a CSV file suitable for Excel…