measuring time elapsed for file output.

[vaib]

Hello Thaks for the folow up I tried your idea here but the code is not working properly i.e the indiacator i attached to the subtract function was not showing the time interval instead it was continously fluctuating between random numbers. I am posting the modified code along with the .jpg file for your perusal. Kindly advice appropriate modifications Thanks in advance. Vaib

[smercurio_fc]

I have no idea which VI I'm supposed to be looking at. Is it the 2.6 or the 2.8 one? The 2.6 has no subtraction, but it has some stuff about timing which attempts to do some control. The 2.8 has nothing about timing, but some subtractions to measure how long it takes to write something to a file. Also, your requirements are now different than what you originally stated. It now seems you want to write to file with the additional condition of if the voltage is above a certain value. Please explain exactly what it is that you want.

[vaib]

Thanks a lot for replying and I am sorry if my words were misleading. Well I have 2 pressure sensors which measure pressure and two points down a pipe. and I want to view this data both on the screen and on a file. However I want the data writting procedure to be triggered be a valve which shows a voltage change if it opens and voltage becomes close to zero once it closes. In addition to this I want the program to write in the file only for a certain time interval which I want to be independent of the while loop timing using the express vi used in the program. Now 2.6 is the program which i modified on your suggestions. While 2.8 is the one which was modified according to Mr. MIke's suggestion. So I guess we should be looking at 2.6 with you and 2.8 with Mike, I excluded the timing control in Mr. Mike's program as i found it not worthwhile to have two timing controls in the same program. Now please advice me as to what would be the best solution for this tricky problem All your advice is highly appreciated Thanks in advance Vaib

[vaib]

So what do you all say is this doable, or should i work on something as a substitute. Vaibhav

[smercurio_fc]

Please give folks here some time. We occasionally have to do some work for our regular jobs.

Mike's suggestion was based on the presumption that you were trying to stop the file write while it was writing. That's not what you're trying to do, so let's forget that.

There's one aspect of your requirements which seems a little odd. You say you want to initiate the file write once a valve is opened, and stop it once it closes. But, you want the file writing to stop even if the valve remains opened and you've been logging for X seconds. That seems odd to me, as you would be missing data while the valve remains open. Is this right?