Multifunction DAQ

Showing results for 
Search instead for 
Did you mean: 

Excel file size when writing data

I have a DAQ device which is reading 14 Thermocouples at 1 measurement every 4 seconds.  I took around 4 hours worth of readings before stopping the experiment, the last reading was at 12:30 but I didn't stop process until 13:15.  The file size is 2.5mb, any reason why it didn't continue to write data or is there a limit to how much can be written to an excel file?  Any advice would be greatly appreciated.

0 Kudos
Message 1 of 7

Hi Matt,


Could I ask what DAQ device you are using? 


Thank you.

0 Kudos
Message 2 of 7

Hi, I'm using a DAQ-9174 with a NI-9213 Thermocouple module.

0 Kudos
Message 3 of 7

What version of Excel are you using?  Excel used to have a limit of 65,536 lines (or something around there).  What you are describing sounds a lot like you ran into that issue.


Can you share some code?  Maybe we can give you a better way to save and view the data.

There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines
"Not that we are sufficient in ourselves to claim anything as coming from us, but our sufficiency is from God" - 2 Corinthians 3:5
0 Kudos
Message 4 of 7



It might potentially be an issue with the USB port on your computer. What operating system are you using? The USB Power Management in Windows tends to cycle power to the USB port after a period.

0 Kudos
Message 5 of 7




I'm using Windows 7 Pro.


The excel file had 3197 lines before it terminated.


Thanks for your help

0 Kudos
Message 6 of 7



You could go into the Device Manager and edit the power management setting of the USB device. There is a setting called "Allow the computer to turn off this devoce to save power" which shuts off things connected by USB after a period. If you deactivate it you might be able to fix your issue. 

Also have you included any error handling to see if an error causes the device to stop logging?


Thank you.

0 Kudos
Message 7 of 7