acquire data with time t=0

[dragon-long]

Hi Friend

The attached file is one VI which collect data of sin, cos function.

When I click acquire button, data will be written to the file.

The problems is I hope when I click acquire, the time value recorded to file is starting from 0s. But it always showed some time delay (7s.)

I do not know how to solve this problems

Thanks for your help

[vt92]

Your t0 is the time difference between the start of the program and the time when you press "Acquire".  You would need to reset the start time whenever you press Acquire.  I recommend using an event structure.

[vt92]

Something like this:

[dragon-long]

Ok

Thanks

Let me try

[dragon-long]

I worote program like you said. It exactly give me time from 0s.

But the new question is how can I exactly acquire data which is like 0s, 1s, 2s,

right now It has a little delay

Thanks for your help

[vt92]

Use the Get Date/Time in seconds primitive (or Elapsed Time express VI) to determine when 1 second has elapsed instead of just waiting exactly 1000 ms.  Your other code has some overhead which is causing the loop time to be > 1.0 second. 

[dragon-long]

Hello VT92

I tried many hours. It still does not work.

I posted my code.Could you advice me where it is wrong?

Elaspsed time is not correct. Porbably I need to set up correct start time, right?

[vt92]

Try this.  The accuracy is dependent on the event structure timeout.

[dragon-long]

I tried it, The new problem is when I log data, it is not starting from time =0s, 

.Thanks for your help