Batch Processing of DDF files (non multi files)

[Andy Phillips]

Hi,

Wondering if anyone can help me sort this problem out -

I produced a worksheet in Dasylab 10 to stream data to DDF files.  The files are named with the date and time using global strings.  I have an action module on the sheet that closes one file and then opens another every ten minutes.  I produced many of these files over a continuous 48 hour period.

What I now want to do is write a worksheet that will analyse the data recorded within the files.  I don't want to sit there opening and closing each individual file.  How can I get Dasylab to automatically open the next DDF file in the sequence when it has come to the end of one file and then keep doing this until all my 48 hours worth of files have been analysed?

These were not recorded with the multi-file option.  The file name simply follows the form ${DAY}_${MONTH}_${YEAR}_${HOUR}${MINUTE}${SECOND}.DDF as I thought that this would be more meaningful for such a large number of files.

Problem is I can't see any easy way to now automatically open each file in sequence.  There must be something clever you can do with variables or strings or possibly the sequencer but I just can't see it myself so any tips would be very very welcome.

Thanks in advance,

Andy Phillips

[Hillman]

Hi Andy Phillips,

Thanks for the post.

Im not very familar with DasyLab.

One of my thoughts was, if the file name contains the time, won't the directionary list the files in order - and hence you would just need to read the files from top to bottom?

Secondly, can you perform string searches in DasyLab, because in labview you can list all the files in a directionary (which the names are stored in a string array), then open/close them reading the data out.

I agree, your file format is more meaningful.

Could you post a few DDF File, so I can 'play'.

Kind Regards,

[Andy Phillips]

Thanks for the response.  Each DDF file is about 1.8 GB, they were sampled at 100kHz for 10 minutes each so I don't think you'd want me to post them - up/down loading would take some time.  The whole thing is approx 0.5 TB.

I have come up with a solution of sorts - rename them into a numerical sequence starting at zero and ending at 6 x 48 (48 hours of 10 minute files).  I'm just backing up the data now which is taking forever, then I'll rename which will probably take forever, even using a dedicated batch rename utility.  Pretty obvious solution really, but it's not very elegant.

I did have a kind of solution worked out by loading all the file names into global strings from a .ini file.  Then I used another string to load in the filename from the other strings based on the status of a global variable using the 'strsel' function in the extended functions part of global strings.  The variable would increment each time a file reached EOF so that the next file in the list was referenced.  It was a pretty clunky solution as the 'strsel' statement was nested a lot of times.  I can't see why it shouldn't work but it didn't.

I'm sure LabView would do it but we've invested in Dasylab.  We weren't aware that the documentation was so scant at the time of purchase.  I think Dasylab is powerful enough to cope with our needs but unfortunately the documentation only really covers basic applications and the more advanced functions aren't very well described in the online help.

We do have copy of LabView 6 with the full developer licence but I've been quoted a few thousand pounds to upgrade that to the latest version.  It's only a few hundred pounds a time to upgrade Dasylab and that is a lot easier to justify to our money men.

Cheers,

Andy

[Hillman]

Hi Andy,

Thanks for the reply.

I completely understand what you've said - very clear! (and i agree).

I think (with my knowledge) that what you're doing sounds good.

Maybe you could try,

The www.dasylab.com web page has an extensive list of technical notes.
The IOtech web site also has Application Notes and Tech Tips that relate to the DASYLab software.
Measurement Computing Corporation maintains a web Forum with a DASYLab section.

You can request help directly from a support engineer by going to the Support section of the www.dasylab.com web page. This is automatically routed based on geography,  to the person best suited to assist you.

Good Luck with your application, sorry I couldn't help anymore.

kind Regards,