Reading a binary file

Similar Questions

• What is the best way to read this binary file?

  I wrote a program that acquires data from a card DAQmx and he writes on a binary file (attached file and photo). The data I'm acquisition comes 2.5ms, 8-channel / s for at least 5 seconds. What is the best way to read this binary file, knowing that:

  -I'll need it also on the graphic (after acquisition)

  -J' I need also to see these values and use them later in Matlab.

  I tried the 'chain of array to worksheet', but LabView goes out of memory (even if I don't use all 8 channels, but only 1).

  LabView 8.6

  I think that access to data is just as fast, what happens to a TDMS file which is an index generated in the TDMS file that says 'the byte positions xxxx data written yyyy' which is the only overload for TDMS files as far as I know.

  We never had issues with data storage. Data acquisition, analysis and storage with > 500 kech. / s, the questions you get are normally most of the time a result of bad programming styles.

  Tone

• Reading a binary file - access error

  I am new to the discussion Forum OR and had a basic question on the use of Labview to read a binary file.

  For my application, I need Labview to collect a single value (pulse width) of a custom program that is written in C++. Currently, this value is stored in a temporary file of binary data. I'll run Labview and the custom program at the same time.

  Is it possible to read a binary file using Labview while the file is written by another program to? At the moment I get an access error. I use a binary code to read the library of example Labview base.

  Thanks for your suggestions!

  I'm surprised that Windows would let you copy of the file if the other program still has a lock on it.  How you try to open your file in LabVIEW now?  Maybe if you open the file with accesss unalterable, Windows will allow you to open it in LabVIEW.

  Yes, you can copy files in LabVIEW.  There are functions to copy under the palette file IO.  In addition, you can use a copy within the service system Exec command.

• Read large binary files in addition to 1,000 records

  I have a few large binary data files created in Labview which cannot be entirely read in Labview. Normally acquire us data in Labview and analyze in Matlab. But now we need to read them in Labview. The files have a header that tells us very well. Then there is data of 64 channels. There is a piece of data of each channel for each stamp of time for 300 000 locations. The table of data read in is therefore 64 lines by 300 000 columns.

  MATLAB reads these files in their entirety. But Labview will show only the first 1000 columns. After reading the data file my table is only 64 lines per 1000 columns. It seems that is the default maximum table size or the maximum number of records for Binary File.vi reading is somehow limited. I searched and didn't find an answer.

  

  My vi is attached. The data file is too large to post on the forum. If someone can tell me how to post large files, I'll put it up.

  Any help would be greatly appreciated!

  I can't download your data file.  It is blocked by my antivirus because it is suspicious of your file hosting websites.

  You have your program that creates the data file?  See how writing can say more how the data file is packaged.

  Try to set the data type for the last reading a constant I16 rather than an array of 2D I16.  When you read a 2D picture, he expects that size data in row and column to be part of the information, in that it is reading.  If this information is not there, then it will be you end up with an error message you get.

  If the data have been written just as a series of values I16, then row and column sizes will not here.  Then read in as a type of data I16 and you will get a 1 d table as long as necessary.  Then, you would need to remodel in a table 2D of the appropriate dimensions.

• CEP - read the binary file (png) and download with $.ajax

  Hi all

  I'm trying to create the POST request with extension PRC binary image

  I read the PNG file under

  fileContents var = window.cep.fs.readFile (fileData.files [f], cep.encoding.Base64);

  Then I need to create the object with that content converted to binary Blob data (?), but I always

  Error: InvalidCharacter

  Error: Exception of DOM 5

  Please notify

  found the solution

  Use the function base64DecToArr to mozilla foundation

  https://Gehrcke.de/files/perm/blog/2015/jsDecode/test.html

• Structuring of data read from binary file

  Hi people,

  I am very new to matlab and trying to get a comprehensive program that will read my library of recordings of electric fish.  It is a simple binary format which auto contains information necessary for playback.  After a few days before the software, I was able to write a single passage that dissects the first record of my file.  However, I want to structure the data, so that I can easily navigate through each record added to a particular file.  I attatched the file .vi so far I came with... I don't know that I have to write a loop and add data to a table or a cluster, although the procedure for this escapes me.  Is there an effective way more to code this?  Thank you very much for any help you can be able to provide!

  Best,
  JG

  Well, I made my mistake cardinal on the forums and called Labview Matlab in my previous post.  Apology.  I've made some progress on this point, with a loop that adds data to a structure...

  Now, I would like to find a way to achieve more effectively... Any ideas?  Thanks in advance!

• Problem writing to / reading a binary file in a loop

  Hello

  As you can see in the image of rasthaus, I try to write a 2 * 202 data set in each iteration of the loop the loop, but when I try to read the data (on the second picture) I only have the first (or, I guess) set of data, up to 202 index. I needed to read the two together (X, Y) of valuse 402. So, I don't know if I'm wrong to write Victorian in the file or playlist, it!

  I really appreciate it if someone could suggest a solution

  Mary

  Your file has only 1 set of data in it.  But looking at the code to write the file, I think that your error is with the setting of the file position.  The default position is the beginning of the file, which means that you will just be overwriting all data you have in the file.  You must specify to set the end of the file by setting the entry of 'From' to 'end '.

• read/write binary file in struct

  Hi all,

  I created a profile of struct defined as follows:

  typedef struct {profile

  name char [30];
  Electric float;
  Double frequency;
  Profile of struct * next;

  }

  I can write structures in a file, but I have to do that when you try to insert a struct, you control the domain name and only if there is no other struct with this name, it is inserted into the file.
  Please help me!

  I solved it!

• Work of doesn´t of reading binary file on MCB2400 in LV2009 ARM embedded

  Hello

  I try to read a binary file from SD card on my MCB2400 with LV2009 Board built for the ARMS.

  But the result is always 0, if I use my VI on the MCB2400. If use the same VI on the PC, it works very well with the binary file.

  The
  access to the SD card on the works of MCB2400 in the other end, if I
  try to read a text file - it works without any problem.

  Y thre constraints for "reading a binary file" - node in Embedded in comparison to the same node on PC?

  I noticed that there is also a problem
  with the reading of the textfiles. If the sice of the file is approximately 100 bytes
  It doesn´t works, too. I understand can´t, because I read
  always one byte. And even if the implementation in Labview is so
  bad that it reads the total allways of the file in ram it sould work. The
  MCB2400 has 32 MB of RAM, so 100 bytes or even a few megabytes should
  work.

  But this doesn´t seems to be the problem for binary-problem. Because even a work of 50 bytes binary file doesn´t.

  Bye & thanks

  Amin

  I know that you have already solved this problem with a workaround, but I did some digging around in the source code to find the source of the problem and found the following:

  Currently, binary read/write primitives do not support the entry of "byte order".  Thus, you should always let this entry by default (or 0), which will use the native boutien of the target (or little endian for the target ARM).  If wire you one value other than the default, the primitive will be returns an error and does not perform a read/write.

  So, theoretically... If you return to the VI very original as your shift and delete the entry "byte order" on the binary file read, he must run a binary read little endian.

  This also brings up another point:

  If a primitive type is not what you expect, check the error output.

• read in a labview complex binary file written in matlab and vice versa

  Dear all. We use the attached funtion "write_complex_binary.m" in matlab to write complex numbers in a binary file. The format used is the IEEE floating point with big-endian byte order. And use the "read_complex_binary.m" function attached to read the complex numbers from the saved binary file. However, I just don't seem to be able to read the binary file generated in labview. I tried to use the "Binary file reading" block with big-endian ordering without success. I'm sure that its my lack of knowledge of the reason why labview block works. I also can't seem to find useful resources to this issue. I was hoping that someone could kindly help with this or give me some ideas to work with.

  Thank you in advance of the charges. Please find attached two zipped matlab functions. Kind regards.

  Be a scientist - experiment.

  I guess you know Matlab and can generate a little complex data and use the Matlab function to write to a file.  You can also function Matlab that you posted - you will see that Matlab takes the array of complex apart in 2D (real, imaginary) and which are written as 32 bits, including LabVIEW floats called "Sgl".

  So now you know that you must read a table of Sgls and find a way to put together it again in a picture.

  When I made this experience, I was the real part of complex data (Matlab) [1, 2, 3, 4] and [5, 6, 7, 8] imagination.  If you're curious, you can write these out in Matlab by your complex function data write, then read them as a simple table of Dbl, to see how they are classified (there are two possibilities-[1, 2, 3, 4, 5, 6, 7, 8], is written "all real numbers, all imaginary or [1, 5, 2, 6, 3, 7, 4) [, 8], if 'real imaginary pairs'].

  Now you know (from the Matlab function) that the data is a set of Sgl (in LabVIEW).  I assume you know how to write the three functions of routine that will open the file, read the entire file in a table of Sgl and close the file.  Make this experience and see if you see a large number.  The "problem" is the order of bytes of data - Matlab uses the same byte order as LabVIEW?  [Advice - if you see numbers from 1 to 8 in one of the above commands, you byte order correct and if not, try a different byte order for LabVIEW binary reading function].

  OK, now you have your table of 8 numbers Sgl and want to convert it to a table of 4 complex [1 +, 2 + 6i, 5i 3 +, 4 + i8 7i].  Once you understand how to do this, your problem is solved.

  To help you when you are going to use this code, write it down as a Subvi whose power is the path to the file you want to read and that the output is the CSG in the file table.  My routine of LabVIEW had 8 functions LabVIEW - three for file IO and 5 to convert the table of D 1 Sgl a table of D 1 of CSG.  No loops were needed.  Make a test - you can test against the Matlab data file you used for your experience (see above) and if you get the answer, you wrote the right code.

  Bob Schor

• "Read binary file" in hex format?

  Is there a way I can set the data type of the function "Binary file reading" so he came out in Hex format?

  Front panel.  Right-click.   Display format.

• "Read binary file" and efficiency

  For the first time I tried using important binary file on data files reading, and I see some real performance issues. To avoid any loss of data, I write the data as I received it acquisition of data 10 times per second. What I write is an array double 2D, 1000 x 2-4 channels data points. When reading in the file, I wish I could read it as a 3D array, all at the same time. This does not seem supported, so many times I do readings of 2D table and use a shift with table register building to assemble the table 3D that I really need. But it is incredibly slow! It seems that I can read only a few hundred of these 2D members per second.

  It has also occurred to me that the array of construction used in a shift register to continue to add on the table could be a quadratic time operation depending on how it is implemented. Continually and repeatedly allocating more larger and large blocks of memory and copy the table growing at every stage.

  I'm looking for suggestions on how to effectively store, read effectively and efficiently back up my data in table 3-d that I need. Maybe I could make your life easier if I had "Raw write" and "read the raw data" operations only the digits and not metadata.then I could write the file and read it back in any size of reading and writing songs I have if you please - and read it with other programs and more. But I don't see them in the menus.

  Suggestions?

  Ken

  
  

• file read write binary error 116

  Hi all

  I am double, digital table in binary data record and then try to read back but keep on getting error 116 (cannot read binary file).

  I've attached screenshots of the way I write my data in the binary file, then the way I'm reading it. Basically, my data are pieces of 2D double bays, which come at a frequency of 1 Hz and this is why I use the GET and set file size before saving to the file (i.e. so that whenever I add my file with new data).

  I tried all combinations for binary and read Scripture to binary functions, which meant that I tried a few options big endian and native, but I keep getting the same error. Also played the way I add my data, i.e. I used the options of 'end of file' and "offset in bytes" just in case it makes a difference, but again no luck.

  Any help would be much appreciated.

  Kind regards

  Harry

  Try to set the 'pre append array or string of size' true.

  That seems to work here...

• Read and analyze a binary file

  I can't properly analyze a binary file. I use the Labview 'Reading binary file' example, I joined to open the file. I suspect that I use incorrect settings on the command "binary file reading.

  Here is a little history on my request. The binary file, that I'm reading has given stored as 16-bit and 32-bit unsigned integers. The data comes in blocks of bytes, 18; in this piece of 18 bytes are the five values 16-bit and two 32-bit values. At the end of the day, I fear that with pulling on one of the 16-bit of each data segment values, so the amount of the fine if the sorting method interprets the 32 bit values as two consecutive 16-bit values.

  Any suggestions on how to properly analyze the binary file? Thanks for your suggestions!

  P.S. I have attached an example of binary file I am trying to analyze. She doesn't have an extension so I chagned it in .txt for download. It has 40 k + events, and a piece of 18-byte data is saved for each "event", so the binary is long enough.

  You can read the file until all the bytes and do some gymnastics Unflatten or specify the data type for the binary file reading.  No need to feed the size, just let it read all of the file at a time.  Nice how the extracted from cultures of the constant of cluster.

  

• Strange behavior when reading binary file

  I'm reading from the binary data as flattened. The file was saved as a class of labview which contained the table of waveforms and other data. When I read the file with read binary file vi with class attached to the type of data the data are correct. But when I read the as flattened data something strange happened (see attached image). The two best shows correct data and two charts below shows the partially correct data. When you write code to read the flattened data I followed the instructions on http://zone.ni.com/reference/en-XX/help/371361H-01/lvconcepts/how_labview_stores_data_in_memory/ and http://zone.ni.com/reference/en-XX/help/371361H-01/lvconcepts/flattened_data/.

  The strange is that there is gap around 1.4 s (marked in red), but the samples before and after game.

  I don't know what I'm doing wrong.

  I have LV2011.

  Demand is also attached.

  

  

  Assuming that you your decoding of binary data is correct (that is, you have the data structure of the serialized class figured out) the problem is probably that you don't the read as binary data, you read in the text using the text file... Modify the read fucntion than binary.