Problem with Daq relative time

[Bekoki]

Hi,

i'm a beginner and i've a problem (maybe stupid...) with the test bench control i'm realizing. 

Using a Daq (and the NI USB-6211) i acquire 2 analog signals (torque and rpm) and i use them  to calculate speed, power, etc. After the computation i put all the values in a queue and, optionally, i save them on disk.

The VI works but i've a problem with the time: i want a relative visualization starting from 0 but the daq reset every time it acquires 100 (or whatever is inserted in "buffer size") samples... So in the the x-axis i've 0, .... ,0.0999, 0, ...... ,0.099 and so on. How can i obtain what i want? I really don't understand what i have to do and i will very thakful to everyone will help me.

I attach my VI ( I use labview 10). Thanks.

Best regards,

Alessandro 

[Olivier_L · Accepted solution]

Hi,

First, you have to change the display format properties of your X-Axisto display Relative Time datas.

Then, the issue is that DAQmx returns datas correlated to 1st January 1904 as a reference in time. The only way I know to workaround this is to substract the time of your VI start:

Start at Zero with Relative Time Using Waveform Data in Charts

Regards,

[Bekoki]

Hi Olivier,

sorry for the delay but i had other works to do. I read the link, i followed your suggestions and now it works: thanks a lot! 

Now i'll try to make the vi more efficient and well-edited. 

Best regards,

Alessandro