how to import dasylab data (.ddf) to LABView or MATLAB

[Nandhu]

Dear all,

I am new to this forum. Currently in my project, I have made measurements in a steel mill. We have used dasylab for this purpose. The data format with the obtained measurement is .ddf . 10 channels were used for the measurement and the sampling frequency is 1000 Hz.

I would like to import these datas to LABView or MATLAB.

I would like to know how this can be done.

Thanks in Advance,

Best Regards,

Nandhu

[CJ_Butler__DASYLab_Pro]

One easy way is to use DASYLab to convert DDF to ASCii.

Set up a Read Data Module and connect to a Write Data Module.

Configure Read Data first. Find the file, and open it. That sets up the number of Channels. Turn off the "Real Time" option on the left of the dialog box, so that it will replay as fast as possible.

Set up the Write Data module with the same number of channels, and configure to write to ASCII. Click on the ASCII options to select the separator, number of decimals (for each channel), and, very important, the time channel.

There used to be a Matlab utility to read DDF files at www.dasylab.com. Click on the Links at the top of the screen.

Matlab DDF tool

The best way to work with LabVIEW is to use the DASYLab format: DIADEM TDM. You can create it the same way as ASCii... replay the DDF file and create a TDM file. LabVIEW has VIs to read it.

If you have an older version of LabVIEW, or you're really good at LabVIEW, there was a DDF read tool created way back when (1998?)

[StefanR]

You can also try the DASYLab DataPlugin to read the DDF file using the Storage VIs 

Greetings from sunny Aachen

Stefan

[CJ_Butler__DASYLab_Pro]

Thanks Stefan!! I was unaware of that plug in. Just goes to show that I don't know everything about DASYLab, although, I do try.

[CJ_Butler__DASYLab_Pro]

I just tried the plug in. I downloaded the NI example Loading Data with a DataPlugin Within LabVIEW, selected my file, and the plug in (DASYLab), and it read it beautifully.

[Nandhu]

Dear all,

I thank you very much for your replies. The solution with LABview is working well for me.

Best Regards,

Nandhu

[CipherThis]

All, I've been using DASYLab for 12 years, LABView for 5.  CJ Butler is the most helpful person I've ever spoken to with regards to DASYLab.  She really knows her stuff.

[yaris_bs]

Hello.

I have the problem, that I need my enddata in .ASC-format, but because of mixing 4 channels before that I have to use .DDF inbetween.

Could you please explain more precisely how I convert using a Read - and Write module? I didn't understand the part with the time channel. Do I HAVE to use it?- it is a little confusing, because I don't have a time-channel option in the Write DDF-data module.

Thank you in advance!

Greets from Hamburg!

[CJ_Butler__DASYLab_Pro]

If the data channels have different timing, then you'll need to write each channel to its own ASCII file.

DASYLab ASCII requires that each field in each row have a data value. If you have a slow channel and a fast channel of data, then there isn't a value of the slow data for each value of the fast data.

If you really want the data in one file, you can use the Signal Adapt module to up-sample and interpolate the slow data to match the fast data.

The ASCII Option to include the time channel is a convenience to you - it formats the time of the data sample to a time format, either elapsed time from the start of measurement, or the time of day.

The DDF file format is a proprietary binary format that stores the blocks of data to a file. The file header and block header information retain the timing and other data characteristics, so that the data can be read back exactly as it was stored. You don't have to specify those settings; they are automatic.

The ASCII file format is a conversion from the binary internal format to a standard readable ASCII file. We give you more options, so that you can create the file type that you need for other programs to be able to read the file.