LabVIEW
NI USB6001 labview time loop iteration increased automatically in long term test
Hi guys:
I am using NI 6001 to measure the volts of batteries. I config the time loop as following pic.
When I start the experiment, everything is fine, the loop running 1 time per second.
at same time I am writing the volts data to a .xlsx file.
but after a week I checked .xlsx file, every 2-3 minutes, there is a new volts value can be write in this file (I added the timestamp when I configured the write to measurement file).
so, is this loop iteration increased by the writing .xlsx procedure? Or other reasons?
Kind Regards
RichKnight
Hi Rich,
@RichKnight wrote:
I am using NI 6001 to measure the volts of batteries. I config the time loop as following pic.
so, is this loop iteration increased by the writing .xlsx procedure? Or other reasons?
- Why do you need a timed while loop when reading data from your DAQmx device?
- How do you read data from your DAQ device? (Which settings?)
- Why do you need to write to a XLSX file in the loop? (I guess…)
- Why don't you use the DAQmx feature to automatically write data to a TDMS file (with no additional effort)?
- Why don't you show your code?
Hi GerdW:
USB -6001 AI settings as follow pic.
The reason why I would like to use xlsx format is TDMS file can not be opened standard MS excel. I will ask IT if I can install the converter to convert the tdms to xlsx
You can check part of my labview code.
Sorry I just start to use the NI device and Labview, so I deployed a loop for read, write and processing some logics.
Kind Regards,
RichKnight.
Hi Rich,
@RichKnight wrote:
USB -6001 AI settings as follow pic.
Just "slow" 100Hz sampling rate…
Why do you use the DAQAssistent when DAQmx is very easy to use? (Read this, but skip the first chapter.)
@RichKnight wrote:
The reason why I would like to use xlsx format is TDMS file can not be opened standard MS excel. I will ask IT if I can install the converter to convert the tdms to xlsx
Write the data to a CSV file! Much more easy, much less CPU-demanding!
Suggestion:
- You don't need a timed loop as DAQmx will dictate the loop timing!
- You can use simple FileIO, much more efficient…
- Those 3 functions at the bottom replace your whole big formula node…
