LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Write to Measurement file time column

Hi everyone

 

I've currently created a VI that should measure and store DAQ-data continuously in a lvm-file. The time column starts at 0 which is good but after 2 seconds it jumps to whatever (like 18, 20, 32,...) and I have no idea why.

Does anyone of you have an explenation?

Check out the VI attached.

 

Many thanks.

 

sciu

0 Kudos
Message 1 of 4
(2,916 Views)

Hi sciu,

 

a VI that should measure and store DAQ-data continuously in a lvm-file.

No, the VI will save data only when time has elapsed - but not continuously…

 

Do you mind to clean up your VI? (wires from left to right, no hidden code/wires, no hidden labels in the block diagram).

It would also help to get rid of ExpressVIs as much as possible.

It would help to revise the DAQAssistent settings: you are reading 4k samples at 2kS/s samplerate making the VI react quite sloppy…

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
0 Kudos
Message 2 of 4
(2,892 Views)

Hi GerdW

I know, the time has to elapse first before data will be stored. Data should be stored "continuously" when the "time to elapse" is set to "0". It works for all iterations - the time column just counts up. Only after the first Iteration / storing of data the time produces a "jump".

What would you recommend for the sampling rate? The idea was (initially) to store data of 2 sec. after each "time has elapsed" event when the "time to elapse" was set to e.g. 12 sec.

I can follow your advises and rearrange the VI tomorrow.

 

Thanx

 

sciu

0 Kudos
Message 3 of 4
(2,888 Views)

Hi GerdW

I'm sorry for my late reply. Due to some administrative issues I focused on rewriting the code for the program. Thus the Problem is solved - I removed all express-VIs and also the timing parts of the VI since they weren't necessary anymore.

But thanx a lot for your advises.

Best

 

sciu

0 Kudos
Message 4 of 4
(2,866 Views)