Data Logging Issue

[Hydrate]

Hello,

I'm realtively new to the lab view environment.  I'm trying to log three temps and two pressures with the rate determined by the input box.  It keeps popping various errors after running for some time and is not logging at the requested rate.  Thank you!

[Cory_K]

Do you have this code in a loop?
You can adjust the wait in the loop to determine how frequently data will be written to a file.

If there is no loop, how is this code running? (And please dont say you press 'run continuously')

Also, what errors are you getting?
If possible, can you attach your actual code so I can see what is going on.

[Hydrate]

Yes the code is in a loop.  I'll try changing the loop time, but could that be controlled by the input box?

[GregFreeman]

you can wire an elapsed timer express VI to a case structure. When time expires, switch the case structure to true and in the true case have the data recording part of your VI. This also allows you to have a control on the front panel to change the time  for which it counts down (i.e. time target.)

Message Edited by for(imstuck) on 02-02-2009 06:14 PM

[GregFreeman]

is this sort of what you want?

I forgot a wait in the loop so it doesn't become greedy but you'd also want some sort of wait. Maybe 100 ms or something. 

Message Edited by for(imstuck) on 02-02-2009 06:24 PM

[Hydrate]

I think that will do what I'm looking for, but now I'm getting an error 200279 about my buffer size.  I can't set DAQ assistant to on demand, so I have it set to continous sampling.  I have a control box where the user puts in the rate at which they want the data to write to the file.  Also, what are you saying about the wait?  Thanks for all the help!

[GregFreeman]

im not very familiar with the DAQ assistant so someone else coudl probably help you more. As far as the wait goes, you want some sort of wait in a while loop so it doesn't become greedy and spin as fast as possible.

[smercurio_fc]

Why Do I Get Error -200279 When Writing Continuously Acquired Data to a File?

Error -200279 or other Buffer Errors During a Continuous, Buffered Acquisition

Basically, you're not reading the buffer fast enough, so it's getting overwritten. This means you're losing data. What does your new code look like?

[Hydrate]

Here is the new screen shot.  (the write is just cut off)  I'm not sure where to put this wait, outside the conditional area, and inside the loop, just setting there?  Thanks for the help again, I'm just not familiar with much other than python.

[Hydrate]

screen shot attached