Write to Measurement File Defaults Back to "Save to One File"

I'm trying to use the "Write to Measurment File" to make a series of files - but as soon as I hit ok it defaults back to "Save to one file". Even without running the VI it just sets itself back. I've attached files of what it looks like before I hit okay, the settings, and what happens after I close it.
Perhaps this is a bug?
Also, if you can see, I don't want the file to be called testdata__ but there is no way to change the prefix of the file because the box is greyed out. Any way to change that either?
Solved!
Go to Solution.
Attachments:
Capture.JPG ‏70 KB
Capture2.JPG ‏66 KB
Capture3.JPG ‏47 KB

What version of LabVIEW are you using?
LV2009 has some bugs with the Write to Measurement File Express VI.
See this thread for more information.  http://forums.ni.com/t5/LabVIEW/write-measurement-file-save-to-series-bug/m-p/1226104

Similar Messages

  • Hi am trying to save Data into a write to measurement file vi using a NI PXI 1042Q with a real time mode but it is not working but when i run it with uploading it into the PXI it save in to the file

    Hi am trying to save Data into a write to measurement file vi using a NI PXI 1042Q and DAQ NI PXI-6229 with a real time mode but it is not working but when i run it without uploading it into the PXI it save in to the file please find attached my vi
    Attachments:
    PWMs.vi ‏130 KB

     other problem is that the channel DAQmx only works at real time mode not on stand alone vi using Labview 8.2 and Real time 8.2

  • Write to Measurement File Express VI: file name prompt

    I am using the Write to Measurement File express VI to write some data.
    Even though I have not selected "ask user to choose file" and have set a default filename, the vi still prompts me to choose a file. I tried restarting my pc and it used the default filename the first time and then went back to prompting me. I have set the default to overwrite my existing file each time, so I don't understand why I keep being prompted. If you look in the express VI the "ask only once" radio button is selected and greyed out, but I don't know why; I didn't select it.
    (I have the express VI in a while loop and want it to write a line of data to the file each time the loop executes, so it's not convenient to be prompted for the filename each time)
    I'm sure this is my own silly fault but would appreciate some advice
    Thanks, klara
    Attachments:
    2PDCal_USB1v3.01.vi ‏441 KB

    I'd suggest changing the mechanical action of your stop button from "Switch When Pressed" to "Latch When Released".  This might be the only problem.  If you didn't manually change your stop button back to false before running again, your loop would run once and stop, and you'd immediately see the file dialog from the Format Into File function.  Changing the mechanical action would prevent you from needing to manually change it back to false before the next run.
    Message Edited by Jeff B on 02-07-2008 08:48 AM

  • Write to measurement file at every n iterations

    Hi guys,
    I would like some help with saving data in labview 2010 SP1 (base development system). I am using a "Write to measurement fil express VI" inside a while loop and the data out from the DAQmn Read is wired to the signal in of the "Write to measurement fil express VI".
    The way I have wired it is the VI saves the data as a text file after it has recorded 100 samples (the nuber of samples to read in this case was set to 100). I would like to know if there is a way to control the rate at which the express VI saves the data. As in, I want the express VI to save the data at specified time interval or at every nth iteration. I have attached the main VI and its 2 sub-VIs for reference. Please let know if anyone can help me resolve this issue. Thank you for your time and inputs in this regard.
    Raj

    Robert,
    First, you must understand that the above code resides inside a loop. The blue square i terminal is known as the iteration terminal. It provides the current loop iteration count, starting from zero.
    The first input (x) to the Quotient & Remainder Function comes from this iteration count (i) terminal of the loop.
    The second input (y) to the Quotient & Remainder Function comes from the control N.
    We wish to write to the measurement file every N iterations of the loop. If we take our current iteration count (i) and divide by our desired N, every Nth iteration of the loop, the remainder will be zero. For all other iterations, the remainder will be non-zero.
    That being said, we check the remainder and compare it to zero. If it is zero, we will send a True value to the Enable terminal on the Write To Measurement File Express VI. Any time a True value is sent, we will write to file. Anytime a False value is sent, nothing will be written to the file.
    The green new_file input on the Write To Measurement File Express VI is used when the "Save to series of files (multiple files)" radio button is selected in the Configure dialog box of this Express VI. When "Save to one file" is selected, this option does not apply, and so it is not included in the input list, which is why you are not seeing this.
    This new_file input is used to tell the Write To Measurement File Express VI when to start writing to a new file.
     

  • Write to measurement file timing

    I am trying to make a VI that allows the user to turn on and name channels through the front panel. After the user has configured the channels, they can push a button and record voltages from the enabled channels and save them using the "Write to Measurement File".vi.  I would like the user to be able to record a measurement file that is consistent in length each time they push the button...in this case, 5 seconds of data.  The current VI doesn't appear to be doing this...everytime I push the record button, the data gets recorded for 0.045 seconds.  Apparently I must be missing something as this isn't behaving how I expected it to.  See attached VI.
    Attachments:
    Select Channel rev 3.vi ‏244 KB

    It waits 5 seconds then saves the last 10 samples.  Because that is the way you programmed it.  The while loop returns only the data from the last iteration.
    Two ways to do what you want: 1. Read 5 seconds * 200 samples/second = 1000 samples.  No loop required.
    2. Read 10 samples at a time and accumulate the data until you have 5 seconds of data.  To avoid memory reallocations the way to do this is to Initialize an array with 1000 elements outside the loop. Wire it to a shift register.  Inside the loop Read the samples and use Replace Array Subset to put the new data into the initialized array. Wire the output of the shift register to the file VI.
    You generally should not put any time consuming code inside an event structure.  Read the caveats in the detailed help for the event structure.  Consider a Producer/Consumer architecture.
    Lynn

  • Quickie: Write to measurement file VI, how to create new file?

    I am using the write to measurement file express VI in my code and I have wired into it a control that sets the location to save the measurement file
    The only problem is the measurement file has to exist first!! I cant for example, from the front panel, click the browse directory box, navigate to a folder and type in a name for the file. It just says file not found! Its like the file directory control is opening a file to save to, rather than creating a new file in that location
    How can I solve this?
    Solved!
    Go to Solution.

    Project attached
    If I go in browse options what do i do? Just chose new and existing files?
    Attachments:
    engine.zip ‏119 KB

  • Remove milliseconds from timestamp in write to measurement file

    I'm logging data to a binary tdms file using the write to measurement file express vi. I choose my x axis to be time and see that an absolute timestamp is written with millisecond precision. I only need to-the-second precision. Is there anyway to change this default behavior?
    Attachments:
    remove.png ‏10 KB
    remove.png ‏10 KB

    Where is your data coming from. When I open the express vi to look, it looks like the time format doesn't determine that, but the
    signal data cluster coming in does. So where does the data come from, and in what form?
    Putnam
    Certified LabVIEW Developer
    Senior Test Engineer
    Currently using LV 6.1-LabVIEW 2012, RT8.5
    LabVIEW Champion

  • Strange data saved by write to measurment file

    Hi all,
    I have developed a simple program that permits to visualize data from a channel, but it records data, just when the saving data button is pressed. Data are saved through write to measurment file, but unfortunately there is something wrong since the saved data is strange. In the attachment there are the VI file and the saved data.
    As you can see there are several header and dates are strange (i.e. the saving date is 23/12/1916) and I get much more sample than I should have. Why do I get this?
    Any suggestion is appreciated.
    23/12/1916
    Solved!
    Go to Solution.
    Attachments:
    simulated_data.xlsx ‏1426 KB
    read a channel and save data.vi ‏63 KB

    Your many headers may be because of this:
    Beginner? Try LabVIEW Basics
    Sharing bits of code? Try Snippets or LAVA Code Capture Tool
    Have you tried Quick Drop?, Visit QD Community.

  • Include time stamp in Write to Measurement file

    Dear Experts,
    I would like to include the time stamp in the data sheet I saved using a Write to Measurement file. Currently only 1 column of data was saved without the time stamp. Is there anyway I can save the data together with its time stamp in a single file (side by side column)? 
    Thank you.
    Regards,
    CYTeoh

    Did you configure the Express VI to create a time channel:
    Christian

  • Problem with Write To Measurement File Express VI not writing to file if file was deleted after the first call (7.1)

    I'm using the Express Write to LabVIEW Measurement File in LV7.1.
    I have it set to "Save to one file"  and have tried both "Overwrite file" and "Using next available file name" for the "If a file already exists" conditions.
    The path/filename is passed into the function.
    It works fine the first time around.  If the file is deleted before the function is called again, an error occurs since LV is unable to find the file.
    I have had to stop and re-run my program in order to write to use the function again.
    Since I am able to delete the file I assume it was closed but it seems like LV expects it to be there, even though the function was supposed to create/open/close the file...  Is there any way to reset this without stopping/restarting the program?
    Since my application creates several files (only one using the Express VI) I am checking for the filenames and requiring that they be deleted (or a new filename be used) before acquiring data.  Everything has worked great, except for the Express VI.
    Thank you,
    David

    Ok, I've edited the VI you posted to reproduce my error (this time with 8.0). 
    I added a "master stop" and "start log" button.  To demonstrate my problem:
    1.  Run the VI
    2.  Click "START LOGGING" - c:\test.txt is created
    3.  Click "STOP" - c:\test.txt is closed
    4.  Delete the file c:\test.txt with Windows shell or explorer
    5.  Click "START LGGING" - a new c:\test.txt file should be created but instead an error is raised in the Write LabVIEW Measurement File function.
    Any ideas?
    Thanks,
    Dave
    Attachments:
    Write LV Meas File 2.vi ‏96 KB

  • How to populate column titles for y values when using Write to Measurement File Express VI with a tab delimited text-based .lvm file?

    The .lvm file generated by the Write to Measurement File Express VI includes column heading titles for the y values, but they are a default value of "untitled".  See attached example of a sample file when opened in Excel, the values in question are highlighted.  Is there a way to specify the column titles when the file is written?
    This is a similar question to this posting, which received a work around response to use the Write to Spreadsheet File.vi, rather than a solution when using this VI.
    Message Edited by Hightop Raven on 05-02-2007 03:37 PM
    Attachments:
    column_titles.gif ‏13 KB

    Sorry for the late reply.  I was out of the office Friday.
    You can do it, but the code can get rather ugly.  Under the hood, the dynamic data type (the dark blue wire) is an array of waveforms.  In your case, the scalar values you convert to a dynamic data type are being converted to an array of waveforms, each waveform having one element.  You have two options.
    Explicitly convert your scalars to one-element waveforms (t0=0, dt=1) and add the title before conversion to a dynamic data type.
    Convert your dynamic data type to an array of waveforms and loop through them to add the column labels.  The conversion blocks are in the Signal Manipulation Express palette.
    I would recommend 2, since it is the easiest to add.  It is also the easiest to run only on the first iteration.  Just put a case selector around the loop, wire the selection to the While loop iterator, and set the case containing the label code to 0.  The default case simply passes through the dynamic data.
    My apologies for not including a screen shot.  I am in the process of upgrading my machine and can't run LabVIEW.  If you need one, let me know and I can post one tomorrow.
    This account is no longer active. Contact ShadesOfGray for current posts and information.

  • Capturing data using write to measurement file for encoder

    hello dear,
    can anyone help to check with my encoder to measure data?
    i have connect the write to measurement file but when i open the .txt file,
    no result appear, thanks so much for your help
    Solved!
    Go to Solution.
    Attachments:
    encoder capture.vi ‏180 KB

    well, I have never used that method to write data to a file, but if you double click on your write the write LabVIEW measurement file object and look at the configuration you have selected save to a series of files.  Is that what you wanted, or did you just want one file?
    Jim
    Jim
    LV 2013

  • Help with saving time stamps to "write to measurement file" excel format.

    I am having problems saving the timestamps from my data to the write to measurement express vi for excel.  My incoming data is converted from dynamic data to a 1d array for processing, which I understand you lose the time stamp data. I added a new array for time stamps but this array then cannot be converted back to the dynamic data that is requested to go into the write to measurement file express vi.  I would prefer to leave the data in an array to be saved rather than converting it to a waveform so is there any way to add the time stamps from my 1d array back into the write to measurement file? 

    I set it up to build a waveform now but I am still having issues with it saving the correct timestamp.  The time just incriments for every second (as it did before converting the dynamic data to the waveform). I attached a screenshot.  
    Attachments:
    waveform.png ‏36 KB

  • "Write to measurement file" express VI (TDMS foormat) keeps file opened

    Hello!
    I am trying to use "Write to measurement file" express VI to write TDMS data obtained from DAQmx in LV2011. Each run of the same write function creates new file.
    It seems that last written file remains to be opened until program stops or next file written. It has 0 size and it is not possible to access it from other programs.
    Is it possible to save file immediately and close it?
    Solved!
    Go to Solution.

    It seems, that wiring "DAQmx task" (for AI task) to "Write to measurement file" express VI does not works in my case (only in exe).
    The error is the same as file not found (error code 7), but file is created. Something gets wrong inside express VI. I am unable to debug exe, so I have just disconnected DAQmx task from express VI (really don't specially need it anyway).
    For sure, the same LabVIEW version and drivers are installed on target and VI is working in it as well as at dev machine.
    Debug error which I had encounter is already published in the forums elsewhere. It seems that the problem is in VI without block diagram inside hierarchy. Maybe with Express VI.
    PS test app writing tdms files the same way is working like a charm (without DAQmx task wired).
    So, thank you for yor advices, the problem seems to be solved. Maybe I will have a look in more details about the reason of such error, but can't do it now.

  • Write to measurement file will not ask for file name once as selected.

    When using the Write to Measurement file Express VI.  I select "Ask user to choose file" and "Ask only once" with the intention that the data from each iteration simply be appended to the chosen file.
    I select "Run continuous" and the VI asks for me to choose a file repeatedly anyway instead of just appending the first file.  Selecting "Write to one file" properly appends data to the file specified in the box.
    Am I doing something wrong?

    DianeS wrote:
    Personally I can't figure out why that particular button even exists (I'm told it's occasionally useful for debugging).  
    I find it useful if I am creating a subVI that is supposed to be a part of another VI.  No while, loop just some inputs and outputs as a function.  If I want to test it out stand alone and try a variety of inputs, then Run Continuous and change the inputs, then I see immediate feedback on the outputs.  Once I'm satisfied its working right, then there is no need to clean up.  Just save it and drop it in the large VI as a subVI.
    Beyond that, I see no need for Run Continuous.

Maybe you are looking for