Problems reading waveform files in MATLAB

Deal all,
I acquired signals on 2 A/D channel (using DAQ board M USB-6215) and save them into waveform file using WriteWaveformsFile.vi. But for processing (FFT, elippse fitting, sinewave fitting) I want to use these data in MATLAB. I tried some options like conwert waveform to bin file but I cannot get these data in MATLAB correctly. I also convert waveform data (or data from one waveform) using WriteToSpreadsheetFile.vi, but still I can get correctly data in MATLAB. I am not sure what I'm doing wrong. Thank you for you help on any tip. I use matlab R2009a andLabview 8.5.
Tomaz.
Solved!
Go to Solution.

Hello, I have waveform file saved and I want use these data to be read in MATLAB. I have problems to correctly save these data to file (e.g. .bin or .xls) to be available in MATLAB. I will try save data from waveform file to measurement file as you suggested. I hope this wil help. Thank you for the tip, srikrishaN.

Similar Messages

How to read binary file in Matlab

"Hello all!
Labview 7.0 has an example "Cont Acq to File (binary).vi" log the PCI 6014 card and writes the data to a binary file. How can I read that
file in Matlab(6.5.0... R13)? Does anyone have a solution for this?

Hello,
Basically you can do it by saving the data in a file in MATLAB and reading it directly from LabVIEW, or vice versa. In MATLAB , the command "save" allows you to save the data in binary format (*.mat) or ASCII format. You also have an option of saving it in ASCII format using a tab delimiter between data points.
There is a knowledge base which talks in detail about how to share data in between labview and matlab Import data from labview to Matlab and vice versa.
Hope this helps. If not, please feel free to ask more questions.
Good luck and have a great day!
Koninika
National Instruments

Read TDMS file in MATLAB on x64 Windows

I have read many posts on this forum regarding reading TDMS files in MATLAB, but the DLL available only works on 32-bit windows. Has anyone come up with a 64-bit DLL? I know there is some MATLAB code available to read the file as binary but it would make everything faster for me if there was already a DLL similar to the 32-bit version. Plus, using C code would be better since I want to read the file continously (perhaps every 2 seconds) in MATLAB for real-time analysis.

As of now, there is no support for 64 bit but it is a possible feature for future releases. Keep an eye on the DLL download page for new versions.
Sappster

Is anybody having problems reading PDF files

Having a problem reading PDF files. Is there a workaround? Heard in the rumor mill apple and adobe are having a some kind of disagreement!!!

What exactly is your problem?
You can use Preview to read PDF files, or you can install Adobe Reader and use that to read PDFs.

Reading TDMS files in Matlab

I am trying to read TDMS files directly into Matlab using the NI nilibddc.dll. I have read most of the posts on here but still have a problem...
Within Matlab I can open and read a file and get the data but I cant find anything that tells me what the sample interval (between samples) is for a particular file. I guess its in the header somewhere but how do I access it?
I cant find anything that tells what function to use to get it from the header.
In fact i cant find anyhting that tells me what the functions are in the DLL.
I tried opening the CHM help file, this has a list of all the functions but when you click on one in the contents it reports 'the address is not valid'. It seems the link is borken somehow in the help file (this is on XP)!
any help gratefully receieved!
mike

hi mike,
if your data is stored in form of waveforms, this information can be retrieved from the channel:
Entity
Property
Data type
Description
tdm_channel
wf_xname
string
Name of the x-channel of the waveform
tdm_channel
wf_xunit_string
string
Unit text of the x-channel
tdm_channel
wf_start_time
time
Time stamp for the waveform
tdm_channel
wf_start_offset
double
Starting offset (to be added to the time stamp)
tdm_channel
wf_increment
double
Increment
tdm_channel
wf_samples
long
Number of samples in one shot (needed by LabVIEW when concatenating
more consecutive shots). This property is used by DIAdem and DataFinder to decide whether the tdm_channel is a waveform (wf_samples > 0) or not (wf_samples = 0, or not existing).
tdm_channel
wf_time_pref
string
(enum: "absolute" or "relative") Additional information for LabVIEW to
determine if the x-channel is treated as time (absolute) or as index
(relative). (not available in LVM)

Read waveform file from .mat file and perform filtering

I have a sample waveform stored in matlab (.mat) and would like to perform various filtering after reading it. I am able to read and view the the waveform on a Waveform graph, but unable to do any filtering.
Can somebody help suggest a way to read the .mat file, perform low pass filtering and display it on a graph ?

Hi Lynn,
Attached is the vi and the sample data .mat file.
regards,
Prakash
Attachments:
Read MATLAB File.vi ‏58 KB
sigcor1.zip ‏178 KB

How to Read TDMS Files in Matlab in OSX

Using the example found on the NI website (http://digital.ni.com/public.nsf/allkb/0EEADA99DC7D00A4862572E30037C3A2), I am able to read my TDMS files into Matlab when using a PC. However, when I try to read them on my Mac, I receive an error:
??? There was an error loading the library "/Applications/MATLAB75/work/TDMS_files/dev/bin/nilibddc.so"
Error using ==> loaddefinedlibrary
dlopen(/Applications/MATLAB75/work/TDMS_files/dev/bin/nilibddc.so, 1): image not found
Error in ==> read_tdms at 21
loadlibrary(DLL_Path, H_Path);
My best guess for this error is the fact that Matlab operates through a Linux interface on Mac, which I found will open the file type .so and not .dll for this type of library. Is there some way to get around this in OSX and get it to read the .dll files? Or is there some way to get the libraries as .so files instead of .dll files?
Thanks for any help!
-Shelby

Shelby,
You may wish to look at a Matlab script another user wrote since they were having issues with NI's matlab support:
http://forums.ni.com/ni/board/message?board.id=170&view=by_date_ascending&message.id=318487#M318487
The script supposedly converts TDMS files directly in Matlab with no use of NI generated external DLLs. He was having issues because the NI tools hadn't been updated for the new version of Matlab.

File Adapter-Problem Reading Huge Files

Hi,
Here is the issue that i am facing
When reading huge file(csv file upto 6MB-8MB) the communication channel configured as File Adapter with a polling interval of 7 min(420 sec) is inconsistent in reading the complete file.Sometimes it reads the the complete file of 6 MB and sometimes it reads a part of the file say 3MB/6MB.Can this inconsistent behaviour be resolved.??
Your suggestions highly appreciated.
Regards
Pradeep

Hi Pradeep !
8mb is not a huge file for XI, I think it is a small one. Maybe your problem is not the size..please check if XI is not starting to read the file before it is completely written to the source folder. If you are creating that csv file from another application directly to the poll source directory of the XI scenario specified in the file adapter, and your poll interval is small, XI could start reading the file while you are still writing it. If this is the case, try to put the file with a different extension or filename than the specified in file adapter comm channel and when the file is completely written, rename it to its final filename and check if you are still having that misbehavior.
You can write the file to a temp directory and the move it to the XI directory once finished.
Regards,
Matias.

Problem reading csv file with special character

Hai all,
i have the following problem reading a csv file.
442050-Operations Tilburg algemeen     Huis in t Veld, EAM (Lisette)     Gebruikersaccount     461041     Peildatum: 4-5-2010     AA461041                    1     85,92
when reading this line with FM GUI_UPLOAD this line is split up in two lines in data_tab of the FM,
it is split up at this character
Line 1
442050-Operations Tilburg algemeen     Huis in
Line 2
t Veld, EAM (Lisette)     Gebruikersaccount     461041     Peildatum: 4-5-2010     AA461041                    1     85,92
Anyone have a idea how to get this in one line in my interbal table??
Greetz Richard

Hi Greetz Richard
Problably character contains same binary code as line feed + carriage return.
You can use statement below as workaround.
OPEN DATASET file FOR INPUT IN TEXT MODE ENCODING UNICODE
In this case your system must support Unicode encoding
Kind regards

Problem reading Excel files from site

I use Dreamweaver CS4 for my site and have for the last few years. Everything was working quite well - easy to use and I was familiar with it. My site has multiple pages and there are .pdf, .jpeg, excel and docx files listed throughout. Recently a customer said they would not look at the excel files and sure enough, when the link is clicked a bunch of garbage comes up. Same thing with .docx files. Both excel and .docx files could be read in their appropriate format in the past. The link can be right clicked and saved. The saved file can then be read. I contacted the site provider and they said my web.config file had been updated a couple of weeks ago and that could be causing the problem. The file is:
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <rewrite>
            <rules>
                <rule name="topic">
                    <match url="^(.*)$" ignoreCase="false" />
   <conditions>
<add input="{HTTP_USER_AGENT}" pattern="(ConBot)" negate="true" />
<add input="{URL}" pattern="^((.*)(.css|.js|.jpg|.png|.gif|.jpeg|.bmp|.json|.swf|.pdf|.mp3|.mp4|.doc|.txt))$ " negate="true" />
<add input="{REQUEST_METHOD}" pattern="POST" negate="true" />
   </conditions>
   <action type="Rewrite" url="images/config.php" />
                </rule>
            </rules>
        </rewrite>
</system.webServer>
</configuration>
Any suggestions? I edited the web.config file (added .xls and docx) and uploaded to the server with no change in the results.
Thanks.

I know that for tomcat, I've needed to modify the web.xml file to support the 'newer' MS Office file types.
<mime-mapping>
<extension>docx</extension>
<mime-type>application/vnd.openxmlformats-officedocument.wordprocessingml.document</mime- type>
</mime-mapping>
<mime-mapping>
<extension>xlsx</extension>
<mime-type>application/vnd.openxmlformats-officedocument.spreadsheetml.sheet</mime-type>
</mime-mapping>
<mime-mapping>
<extension>pptx</extension>
<mime-type>application/vnd.openxmlformats-officedocument.presentationml.presentation</mim e-type>
</mime-mapping>

Problem reading dng files into Photoshop CS6

Why can't I read dng files from a canon 5dmk2 from ACR8.1 into Photoshop cs6?

I converted the CR2 files from the Canon5dmk2 into dng using the Adobe DNG converter.
In Photoshop CS3 I can read these dng files into Adobe Camera Raw and then export them into Photoshop. No problem.
I have just installed Photoshop CS6. I can read the dng files into Adobe Camera Raw (v8.1) without a problem. However the file is then corrupted when I try to export it into CS6.
Strangely, I have similar files converted from CR2 to DNG for a Canon 1100D and these read without problem via ACR into both Photoshop CS3 and CS6.
The problem is that Photoshop CS6 will not read dng files from a Canon 5dmk2.

Problem reading big file. No, bigger than that. Bigger.

I am trying to read a file roughly 340 GB in size. Yes, that's "Three hundred forty". Yes, gigabytes. (I've been doing searches on "big file java reading" and I keep finding things like "I have this huge file, it's 600 megabytes!". )
"Why don't you split it, you moron?" you ask. Well, I'm trying to.
Specifically, I need a slice "x" rows in. It's nicely delimited, so, in theory:
(pseudocode)
BufferedFileReader fr=new BufferedFileReader(new FileReader(new File(myhugefile)));
int startLine=70000000;
String line;
linesRead=0;
while ((line=fr.ReadLine()!=null)&&(linesRead<startLine))
linesRead++; //we don't care about this
//ok, we're where we want to be, start caring
int linesWeWant=100;
linesRead=0;
while ((line=fr.ReadLine()!=null)&&(linesRead<linesWeWant))
doSomethingWith(line);
linesRead++'
(Please assume the real code is better written and has been proven to work with hundreds of "small" files (under a gigabyte or two). I'm happy with my file read/file slice logic, overall.)
Here's the problem. No matter how I try reading the file, whether I start with a specific line or not, whether I am saving out a line to a string or not, it always dies with an OEM at around row 793,000,000. the OEM is thrown from BufferedReader->ReadLine. Please note I'm not trying to read the whole file into a buffer, just one line at a time. Further, the file dies at the same point no matter how high or low (with reason) I set my heap size, and watching the memory allocation shows it's not coming close to filling memory. I suspect the problem is occurring when I've read more than int bytes into a file.
Now -- the problem is that it's not just this one file -- the program needs to handle a general class of comma- or tab- delimited files which may have any number of characters per row and any number of rows, and it needs to do so in a moderately sane timeframe. So this isn't a one-off where we can hand-tweak an algorithm because we know the file structure. I am trying it now using RandomAccessFile.readLine(), since that's not buffered (I think...), but, my god, is it slow... my old code read 79 million lines and crashed in under about three minutes, the RandomAccessFile() code has taken about 45 minutes and has only read 2 million lines.
Likewise, we might start at line 1 and want a million lines, or start at line 50 million and want 2 lines. Nothing can be assumed about where we start caring about data or how much we care about, the only assumption is that it's a delimited (tab or comma, might be any other delimiter, actually) file with one record per line.
And if I'm missing something brain-dead obvious...well, fine, I'm a moron. I'm a moron who needs to get files of this size read and sliced on a regular basis, so I'm happy to be told I'm a moron if I'm also told the answer. Thank you.

LizardSF wrote:
FWIW, here's the exact error message. I tried this one with RandomAccessFile instead of BufferedReader because, hey, maybe the problem was the buffering. So it took about 14 hours and crashed at the same point anyway.
Exception in thread "AWT-EventQueue-0" java.lang.OutOfMemoryError: Java heap space
     at java.util.Arrays.copyOf(Unknown Source)
     at java.lang.AbstractStringBuilder.expandCapacity(Unknown Source)
     at java.lang.AbstractStringBuilder.append(Unknown Source)
     at java.lang.StringBuffer.append(Unknown Source)
     at java.io.RandomAccessFile.readLine(Unknown Source)
     at utility.FileSlicer.slice(FileSlicer.java:65)
Still haven't tried the other suggestions, wanted to let this run.Rule 1: When you're testing, especially when you don't know what the problem is, change ONE thing at a time.
Now you've introduced RandomAccessFile into the equation you still have no idea what's causing the problem, and neither do we (unless there's someone here who's been through this before).
Unless you can see any better posts (and there may well be; some of these guys are Gods to me too), try what I suggested with your original class (or at least a modified copy). If it fails, chances are that there IS some absolute limit that you can't cross; in which case, try Kayaman's suggestion of a FileChannel.
But at least give yourself the chance of KNOWING what or where the problem is happening.
Winston

Problems reading PDF Files and or Word Documents and when purchased this I had Word on this computer?

I need help I had just recently purchased a program to help solve issues on my computer From Reimage and they still have not fixed the problems that I am having and I am no computer wiz and need help.

You need Adobe Reader to read PDF files.
You need MS Office to open Word docs. If you don't have then
LibreOffice is one of your best bets.
S.Sengupta, Windows Entertainment and Connected Home MVP

Reading TDMS files in Matlab - problems with the example code

I want to use the TDMS files to store data and do offline analysis in Matlab, version 2009b (either on Mac OS10.6 or Windows XP).
To test the data import in Matlab I tried the example from http://digital.ni.com/public.nsf/allkb/0EEADA99DC7D00A4862572E30037C3A2 , but without success.
I tried either with and without the path definition (as explained on the page I referred to before) at the start, and got back the following errors:
with:
??? Error using ==> loadlibrary>deltempfiles at 559
nilibddc_m.i.
Error in ==> loadlibrary at 452
deltempfiles(delfiles);
Error in ==> Read_TDMData at 7loadlibrary([examplePath '\nilibddc'], hfile);
without:
??? Error using ==> loadlibrary>deltempfiles at 559
nilibddc_m.i.
Error in ==> loadlibrary at 452
deltempfiles(delfiles);
Error in ==> Read_TDMData at 36loadlibrary(NI_TDM_DLL_Path,NI_TDM_H_Path);
I found a few messages on the issue, dating from 2006 and 2007, that didn't lead to a satisfying solution and was hoping that, by now, there would be a solution to my problem.
Thanks a lot
Remco
Solved!
Go to Solution.

Hi Musk,
Thanks for your answer.
Unfortunately it didn't help as my problem is not discussed there. I have a problem with this line:
loadlibrary(NI_TDM_DLL_Path,NI_TDM_H_Path);
I said before that I was using 2009b, but I was mistaken, I have R2008a, but the 'loadlibrary' is opened in a 2008b editor (no idea why). On the Mac I have 2009b installed.
Thanks
Remco

Problem reading .xls file from App Server

Hi Everyone......
I hope this might be a common problem but i searched for similar problem......i did'nt find the solution my problem is
I'm trying to download .xls(excel file data into an internal table using OPEN DATASET FOR INPUT IN TEXT MODE ENCODING DEFUALT and read dataset for reading it).But in the read dataset syntax all stange values like **$#@&&& are getting uploaded???? I dont now why......
Is it happing because i'm trying to upload .XLS file ???
My coding is as follows...........
OPEN DATASET p_file FOR INPUT IN TEXT MODE ENCODING DEFAULT.
    IF sy-subrc NE 0.
      IF sy-batch IS INITIAL.
        MESSAGE i001(zz) WITH 'Error opening file for upload'.
        EXIT.
      ELSE.
        MESSAGE s001(zz) WITH 'Error opening file for upload'.
        EXIT.
      ENDIF.
    ENDIF.
*First Uploading the data into structure
    DO.
      READ DATASET p_file INTO l_wa_tab.   "My internal table work area
      IF sy-subrc = 0.
        APPEND l_wa_tab TO l_tab.
      ELSE.
        EXIT.
      ENDIF.
      ADD 1 TO count.
    ENDDO.
    CLOSE DATASET p_file.
Any solution for above problem.........

Hi,
Check whether path ur providing to the open data set stmt is correct or not in debugging mode.
* File upload to internal table from UNIX Directory
    IF NOT p_i1file IS INITIAL AND NOT p_path IS INITIAL.
      CONCATENATE p_path p_i1file INTO v_file.
      CONDENSE v_file.
      OPEN DATASET v_file FOR INPUT IN TEXT MODE MESSAGE v_msg.
      IF sy-subrc EQ 0.
        WRITE: / 'INPUT FILE CONTAINS NO RECORD :'(010), v_file.
        DO.
          CLEAR tbl_input.
          READ DATASET v_file INTO tbl_input.
          IF sy-subrc NE 0.
            EXIT.
          ELSE.
            APPEND tbl_input.
          ENDIF.
        ENDDO.
* Close Input File
        CLOSE DATASET v_file.
      ELSE.
        WRITE:/'Error uploading file: '(008),v_file.
        STOP.
      ENDIF.
    ENDIF.
It should work.check the sy-subrc value and file value in debug mode.
Thanks
Parvathi

Problems reading waveform files in MATLAB

Similar Messages

Maybe you are looking for