Timestamps and measurement file express VIs

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• usefulness of reading the measurement file express vi

  Hello

  I found reading file express vi measure in LV7.1 does not read from the beginning of the file when you run it the second time. Instead, it resume from where it left off last time. Usually, the user would read the entire file measure each time. So when you try to read the second time, it will show an error window saying that it has reached the end of the file (because he was reading the entire file first).

  I wonder how useful to resume from the last stopping point is? Is there a way to start over each time that the VI excute it?

  I'm sure that's how reading file measure works 90%. Whenever she is called in a single run of the application, it will start off the coast where it was stopped. You will need to work with the low level screw to get what you want to do.

  This Express VI works in a similar way the screws and the following functions:
  Open/create/replace file
  Read text file
  Read binary file
  Read the spreadsheet file
  File dialog box
  Scan to file

  And, you can always use the node to set the file Position to set the position at the beginning of the file.

• write to measure file vi bug?

  Hello.

  Looks like I might not be the first with this.  I suspect...

  http://forums.NI.com/NI/board/message?board.ID=170&message.ID=234485&query.ID=1018110#M234485

  I still after that I don't know how many hours days etc., failed to do this work.   I had to go and do a 'real' job, as it is called here for a few days or so, don't play no not with the software, however, is that asked me to do.

  This is all about 'Writing as Data File' express VI comes with LV 2009.   Used as Cree in the document "Getting started with LabView" infamous.   Running on XP Pro, perfectly (until tomorrow "Patch Tuesday" maybe.)

  Writing on a data file Express VI:

  It works the first time, no mistake, a lot of data, the first time entry to activate is made true, even if I leave it is true, thankfully, it creates several KB of the planned just as data file.   Do activation enter False, writing to the file STOPS, again just as expected.

  New do right and produces an error (the chemin\nom of the input etc file is still there and equally valid that it has always been) and no data is written in the file, despite no changes to the inputs of the VI (with the exception of the data of unique signal value)

  However, if give you him a new one (same file path\new) file name, and then he would write in the new file every time.  It's without blocking the program as a whole.

  I can navigate between two files just fine.   But it just will not write to a file first, that it is "Re" active after a deactivation is used.  Re entering the same path\filename is not a solution.  It must be another to wake up the thing.

  As it is, it's worse that useless for any serious application, and as the other party, I can't imagine how he got through the mill of QA.   As the other party, it is sold on the fact that it is supposed to be easy to plant items/icons on the comic and join the dots to make things work.  While largely true and there are a lot of good stuff here, there are a lot of things that exist for travel upward and confuse him.   The help is too small.  I get the phone call and email to other types of NOR, but no solution to the problem.

  If you want a copy of the VI program all the so-called fine, just someone tell me what and how to download it on this forum (very strange).  I can upload images, but I can't find a way to "attach" files, etc.  Or to work through the Getting Started document (as I have now three times!) and you will find the problem.

  Oh, and I seem to have lost the indicator as to how much
  days of "evaluation" I left.  I can't find a switch to make it appear that
  Gray more splash screen.

  Kind regards.

  Dave Baxter.

  Technical Director:

  AR - UK Ltd.

  I think that there is certainly a bug.  I can see where it is going, but I don't know why he got that way.  This VI shows the bug in LV 8.6 also?

  Right click on the entry to measurement file Express VI.  Inside that is a Subvi, called ex_subFileWrite.vi.  It is a clone of a reentrant VI, so it is quite difficult to follow execution through it.

  Somehow the first time through she builds and checks the file name based on what comes into it.  She that stores into a shift register.  If you clear the writing to a file, the shift register is stored which is not a constant of path.  Later, when writing is reactivated, it uses just the path (not a path) from the shift register, rather than back in the name of the input file.

  Exactly where this is really out there, I'm not sure, because express VI makes such a spaghetti with inter twisted code for managing all types of files and in writing the conditions and a lot of manipulation of file file path.

  I think the reason that edit the path and even change back works is that there is an initial control if the path is the same and if it is different, it works with the new file name, if it isn't, then it works with what was stored in the shift register.

  A person of OR should look deeper into this substantive code of the Express VI and try debugging.  I think that there is a bug.

  But here's a work around.  Use a select statement to send the correct file name if the writing is enabled, or a file path empty if it is not enabled.

  

• How to increase the frequency of sampling of several sensors via RS - 485 and writing files of measure?

  I have a vi that:

  -Locate the USB port that RS485 communication device is connected

  -sends a command to each sensor

  -reads a response from each sensor

  -performs a calculation on the answer

  -saves the response to a file of measure

  I used a flat sequence to query each sensor.  I am trying to find a way to modify this vi in order to increase the frequency of sampling on the sensors.  Currently, it takes 2000ms for question 4 sensors and write tot the measures file.  Anyone have any ideas on how to speed up by programming?  I am concsidering on the purchase of a device USB DAQ (USB6000) and rewriting of the vi.  I was wondering if there was some tweek I caould make on the vi.

  Thank you!

  I meant put the time-out on the line, then the reading will be either timeout after 200ms or read the 2 bytes.  Whichever is faster.  Then deletes this 200ms waiting you.  I have attached your vi to show you what I wanted.  I did not notice that it is a hardware or wither then you might want to look in the data acquisition functions.  It will clean up your code and are very easy to use.

• How to incorporate the timestamp and file name automatically select and save the file dialog?

  Hello

  I try to incorporate the name of the file that is the registration of the end user with the timestamp in the selected and save file dialog box. Can you help me?

  Thank you

  

  Hi Mike227,

  I couldn't find a way to immediately make the bat. I guess you need to mess with ActiveX to do. I found an msdn page that could help with this.

  Have you considered simply concatenating the name of the file and the time stamp with a path of the file and save the file when you create it, without inviting the user?

• Conversion of Outlook Express .dbx to Microsoft Live Mail issue box for receiving and sending files conversion

  I am able to convert most of my old Outlook Express files to Microsoft Live Mail, with the exception of the Inbox, and send files.   The two files are not empty.  My OS is Windows 7 64 bit.  The 'Files' file is located in the directory with the .dbx files.  Most of the files have been converted except these two.  The converted file sent.

  Can advise you on what to do to fix this?  I need the information contained in the Inbox, and send.   I have more access to Outlook Express.

  Best regards, Kat

  Unless you left no messages in the Outbox, it must be empty. Messages are just going through there on the way to your mail server.
   
   
  Folders.dbx is the "brain" of the system of dbx files and contains all the actual messages.
   
   
  Now regarding the messages from the Inbox, I don't know why they won't matter in Windows Live Mail. You compact the folders in OE before saving the message store? WLMail has great trouble with import of dbx files. How do you backup and transfer the storage of OE with dbx files folder?
   
   
  If you still have access to the machine with OE, it would be easy to fix. Given that you don't do it, you probably have two options.
   
   
  If you have professional, enterprise or ultimate edition, you can use OE in XP Mode. Who can import all the messages and then we can transfer it to WLMail.
   
   
  How to use Outlook Express in Windows 7
  http://www.oehelp.com/OEnWin7.aspx
   
  If you cannot use the XP Mode, and can not find an OE to 'borrow' to a friend, you will need a recovery tool. Unfortunately, it is not free.
   
   
  DBXpress
  http://www.oehelp.com/DBXpress/default.aspx
   
   

• Exporting files with wrong timestamp and bad "update" folder

  My system is running Windows 7. CC in Lightroom to 2015.

  Yesterday, while working in Lightroom, we have experienced an unexpected failure. (My dog hit the switch! Don't laugh!)

  When the system rebooted, everything seemed normal with the exception that the 'Clarity' legend was missing in the develop module. The cursor worked as expected however.

  Today I have been using Lightroom without any apparent problem until I exported some images for my external storage. I discovered that time 'Date modified' case files have been exported and the files themselves showed the "Date modified" as on 01/01/2000.

  When I import files in Lightroom, it identifies the file date and time correctly and is important to the good year/month/day.

  The system clock is correct.

  . Any suggestions would be welcome!

  Bob.

  Hi loutses,.

  Indeed, I think it's more of a NAS Trier management as LR question, incidentally, you can try to disconnect the disk completely and then plug it in again.

  Also try one last thing, the images that you exported to desktop, now move them to SIN and then see if the sort order.

  Concerning

  Rohit

• Delta t do not update using write in the measurement file

  I write data to a file that is collected with a dt = 0.005 sampling interval (but no hardware DAC.   I would like to save the data in a file LVM with a column, the timestamp and the second data column, and I use the Express VI 'Write in a file measure' in the following Labview code snippet:

  

  The value of the local variable dt is 0.005.   The delta T is saved in the saved file, but the timestamps don't change the initial value of o, o:

  

  What Miss me?

  Thank you

  John

  I wouldn't really call it a workaround solution. This is the expected behavior.

  Build and write like a table and your waveform will be saved correctly.

  If you are going to write a point at a time, all you have to do is to keep track of what you want to use when you build your unique point to t0 and wiring waveform.

  EDIT: Is the column name 'Untitled' bug your client at all? It would have upset me. You can fix it by set the attribute of waveform for "NI_ChannelName."

• Write to measure file by default to 'save to a file.

  I am using the 'write to Measurment queue' to do a series of files - but as soon as I hit ok it is default to 'save to a file. Even without running the VI he defines simply himself back. I have attached files what it looks like before you hit OK, the settings, and what happens when I close.

  Maybe it's 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 area is grayed out. Any way to change this either?

  What version of LabVIEW are you using?

  LV2009 has a few bugs with writing custom 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

• Align the two signals and measure the Phase Shift

  Hello

  I do an experiment in which I use the NI USB-6221 DAQ card. The jury is able to make 250 k samples/second. I want to measure two voltages in a circuit and find the phase shift between them at frequencies between 1 and 10000. First I ouputted a wave sinusoidal frequency variable through the Commission and applied to a test circuit. Then I used the Board to measure the two tensions consecutively (thus reducing the maximum sampling frequency at 125 k). I used the signals align VI and measured the two phases and then calculates the phase shift (VI attached in Phase 1). It worked well for the test circuit I built in which the phase shift went way logarithmique.20 degrees ~84.5 degrees and then stabilized. At frequencies above 5 000 Hz phase shift must have remained constant, but it varies more or less 1 degree. When the phase shift is 84.5 degrees, present a degree of variability is not particularly explicit. When I asked my program on the circuit that I really wanted to measure, the phase shift went from-. 5 degrees up to about 1.2 degrees. The change in the values of phase shift at high frequencies (> 3000) was environ.2 degrees. Given the small phase shift, this variation is unacceptable. Now I tried to use a sequence to each blood individually (increase the maximum sampling frequency to 250 k) and then align the two signals and measure the phase of each shift. When I use align it and re - sample Express VI to realign the two signals, I get the message "error 20333 analysis: cannot align two waveforms with dt even if their samples are not clocked in phase." Is it possible to align two signals I describe here? I enclose the new VI as Phase 2

  Matthew,

  I think I have an idea for at least part of the problem.

  I took your program data and deleted stuff DAQ.  I have converted the Signal on the chart control and looked then what was going on with the signal analysis.

  The output of the Waveforms.vi line has two waveforms, like the entry.  However, arrays of Y in the two waveforms are empty!  It does not generate an error. After some head scratching, reading the help files and try things out, that's what I think is happening: the time t0 two input signals are 1,031 seconds apart. Since the wavefoms contains 1,000 seconds of data, there is no overlap and may not align them.

  I changed the t0 on two waveforms are the same, and it lines up.  The number of items in the tables is reduced by one. Then I increased the t0 of 0.1 seconds on the first element. The output had both greater than the entry by dt t0 t0 and the size of the arrays was 224998.  Reversing the t0 two elements shifts the phase in the opposite direction.

  What that tells me, is that you can not reliably align two waveforms which do not overlap.

  I suggest that you go to 2-channel data acquisition and that it accept the reduced sample rate.  You won't get the resolution you want, but you should be able to tell if something important happens.

  You may be able to improve the equivalent resolution by taking multiple steps with a slight phase shift. This is similar to the way that old oscilloscopes of sampling (analog) worked. Take a series of measures with the signal you are currently using.  The make enough average to minimize changes due to noise. Then pass the phase of the signal of excitement to an amount that is smaller than the resolution of phase of sampling rate and repeat the measurements.  Recall that I calculated that for a 5 kHz signal sampled at 125kHz, you get a sample every 14.4 degrees. If shift you the phase of 1 degree (to the point/mathematical simulation), you get a different set of samples for excitement.  They are always separated by 14.4 degrees.  Take another series of measures. Transfer phase another degree and repeat.  As long as your sampling clocks are stable enough so that frequency does not drift significantly (and it shouldn't with your equipment), you should be able to get near resolution of what you need.  The trade-off is that you need to perform more measurements and may need to keep track of the phase shifts between the various measures.

  Lynn

• I can't drag and drop files in the trash, error code-43 is detected, what should I do?

  I can't drag and drop files in the trash, error code-43 is detected, what should I do? What is an error code - 43?

  You can't empty the trash or move a file to the trash

  If the above does not help, then see below:

  Visit The FAQ XLab and read the FAQ on the waste problems. You can also try using Trash it! 5.1 to solve the problem. Or you can try this:

  Open the Terminal in the Utilities folder, and paste the following at the command prompt:

  sudo rm - Rf ~ /. Trash

  Press RETURN. Enter your administrator password when prompted. It will not echo to screen. Press RETURN again.

  (Someone should tell you that it is dangerous or useless, please disregard the comment.)

• data transmitted from dequeue function measure file incorrect

  Hello

  I'm under Labview Base 2013 and have a vi that reads data from a RS232 port and a digital port OR-USB6002.  I decided to split the loops in consumers/producers, using the functions of the queue, but ran in four snags with the loop of data recovery.

  (1) the digital pulses are displayed correctly in the USB Signal loop, but the recovery loop data does not display data RS232,

  (2) combined in the loop of data recovery in the file of measurement data to write, but are not properly separated in their columns, i.e. a column is displaying data or loops

  (3) stop button is throwing error 1, incorrect path

  (4) thumbs real control when it is plugged into the loop of data recovery and in signals combine to measure file causes the vi runs correctly.  It runs but does not display the data in the tables on the part of the loops and no data is written to the file of measures.

  I added an indicator in the loop of RS2323 and it appears the data correctly on the front panel, but does not appear in the graph.

  I am able to run this vi without the functions of the queue and simply write data files of two separate measures, but these are forces me to synchronize the data set later.  Not quite what I need.

  Image attached vi.

  

  Thoughts?  Will be streaming to TDMS work better to keep separate data streams?

  You think that you have two queues, but you don't actually have.  You named your queues with the same name, so they are the same queue.  So you have race conditions including dequeue will get the data.  Just remove the string names for constants, and it should work perfectly.

• Change the size of window of dialogue of file Express VI

  I use the dialog file Express VI for opening a file.  Opens the VI mode full screen.  I want her to be open in a small window that is similar to my other applications Win7.  It doesn't seem to be a way change this property even after conversion to a standard under VI.  Does anyone know of a VI integrated to open files when the size of the window can be set?  Thank you

  If I open the file dialog box with the Express VI of FileDialog and then double-click the title bar to make it full-screen and then close the dialog box file, next time I open it, it opens to full screen. that is, it seens to remember the size between calls.

  Try to open the file dialog box, resize to a smaller size and its closure then, to see if he remembers so the smaller.

• Re-read in values in the measurement file when the file is updated

  Hello

  I'm trying to control a power supply with labview and adjust the tension. I currently work reading in a file and measures affecting the value in the file. I now have the question I want to update this value when the file is modified, as read in the file again when it is updated and set the voltage again. I've tried several things, but if I put the file in the while loop, then it plays once and then returns 0 after the first loop. Outside the while loop it reads only the initial value.

  I'm quite new to labview so any help would be appreciated.

  Thank you

  E

  You can use the File Info VI for the time that the file was modified.  If the time has changed, read the new values.

• Win 7... \Users\User name REGTRANS-MS and BLF files

  TRANS-MS and BLF files belong in this folder?

  Hey Buddy,

  Welcome to the Microsoft Answers site.

  The regtrans files are linked to your NTuser.dat. NTUser.dat stores information about your profile. It goes the same for .blf files.

  Because they are specific to the user account, the location name \Users\User seems in good condition.

  Hope that answers your question.

  Kind regards

  Shinmila H - Microsoft Support

  Visit our Microsoft answers feedback Forum and let us know what you think.