Possible to use only 1 "write labview measurement file" for writing several files (1 file per channel) ?

[Julien_31]

Hello,

I acquire data on 16 channels and I would like to write 1 file per channel acquired. So I would like to write 16 files.

But is it possible to do that by using only 1 "write labview measurement file" VI ? If so, how ?

(Indeed, I want to avoid using 16  "write labview measurement file" VIs !)

Thanks in advance,

Julien

PS : please excuse my english

[Bob_Y.]

I am not sure, but I don't think that you can.  I think that if you place it in a loop and index out the channel with the loop, you might get it to work, but if you then have this in a loop, (multiple acquisitions) it won't work because it would create a separate file for each sample.

If you do all of your sampling at once and then index on the channel just for the saving, it should work.

This may not be clear, so let me know if it is not and I'll try to explain it better.

Hope that this helps,
Bob Young

[Julien_31]

I am really sorry but that's not very clear.     :-)

What do you mean exactly by "index on/out the channel" ?

I can tell you that my program structure is the following :

[Julien_31]

I am really sorry but that's not very clear.     :-)

What do you mean exactly by "index on/out the channel" ?

I can tell you that my program structure is the following :

[Julien_31]

I am really sorry but that's not very clear.     :-)

What do you mean exactly by "index on/out the channel" ?

I can tell you that my program structure is the following :

[Julien_31]

I am really sorry but that's not very clear.     :-)

What do you mean exactly by "index on/out the channel" ?

I can tell you that my program structure is the following :

[Julien_31]

I am really sorry but that's not very clear.     :-)

What do you mean exactly by "index on/out the channel" ?

I can tell you that my program structure is the following :

[Julien_31]

Sorry I was mistaken. As I said, my program structure is the following :

1) My "DAQ Assistant" VI (single point acquisition on EACH channel, because I have to acquire 1 point on each channel every hour) is in a "for loop" (24 loops).

2) Out of that "for loop", I do a mean of these 24 points (which are in an array, as I enable indexing for the "for loop"), for EACH channel (16 channels => 16 means).

3) I would like to write those means (16 channels => 16 means) in 16 different files with only 1 "write labview measurement file" VI.

4) All those operations are done in a "while loop".

I hope it will be clearer for you, so that you can help me efficiently.

Julien

[Julien_31]

Anyway, if I understand even a little bit what you wrote, it seems that it's not possible, is it ?

[JeffBoettcher]

Yes, this is possible, though as Bob suggests you'd need to put the Write LabVIEW Measurement File in a loop.

This is a little bit confusing, as your DAQ is happening in a loop at a slow rate as you say, and then your file i/o would happen inside another loop within your DAQ loop.  This is the only way to do it with a single copy of Write LabVIEW Measurement File on your diagram.

I've included a ZIP file with a VI (saved in LabVIEW 8.0) and the data files it produced (I did 16 channels).  In case you don't have LabVIEW 8.0 I included screenshots of the diagram and the Write LabVIEW Measurement File config page settings.

Hope this helps!

Message Edited by Jeff B on 02-17-2006 08:02 AM