Read characters in a binary file

I have a file written in binary format, which does not contain data but some text information, I try to read the text information out but don't know what VIs I should use. I open the file use text editor it appears something like this:
È} A A úCš, C²«ŒÂ T)ó>IÉeD C563 SB5POLY CONTACT .123in. DIAM ENERGY: 1; DAMPING: 50 TP104 2
08-09-2005‹ÿýÿçÿÿ±øÿÃíÿNàÿÒÿqÄÿ‡¸ÿ€®ÿ4¦ÿZŸÿ§™ÿÞ”ÿÑÿ[ÿïˆîÙ‡Í{®…úrÚƒ kY‚Âc))]H€"W
I need to extract only the text information out.

Just convert it to a byte array. Then, in a loop, check each for e.g. "printable?" or a desired set of "lexical class" (e.g.2,3,4,5) and built a new array from the subset. At the end, convert back to string. (see attached, LabVIEW 7.1).
(If your string is huge, you should preallocate the array, replace at the current index, then trim it after the loop to the correct size. This optimizes memory allocations).
Message Edited by altenbach on 10-01-2005 09:27 AM
LabVIEW Champion . Do more with less code and in less time .
Attachments:
printable.png ‏9 KB
ExtractPrintable.vi ‏28 KB

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Code-tags sometimes cause wonders, I replaced # with *, as the code tags interprets # as comment, which looks odd:
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}Shouldn't the nextLine test and assignment be in the outer loop? And assignment be to each maze's inner array? Like so:for(int i = 0; i < maze.length; i++) {
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An applet that has to read data from a binary file

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I've been hunting for the source of some crashes on LabVIEW exit and I was finally able to track it down to this. In my application I wrap measurements into objects that I stream into a binary file during the inspection. In another application I read the file again to browse and analyze the measurements. All this seems to work just fine except that the reading part causes LabVIEW to crash once I close the IDE. Built applications don't report any crashes but I am afraid if it might still cause some instability or unexpected behaviour.
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#OSName: Windows 8.1 Pro N
#AppName: LabVIEW
#Version: 13.0f2 32-bit
DWarn 0xEFBFD9AB: Disposing OMUDClass definition [LinkIdentity "Class 1.lvclass" [ My Computer] even though 1014 inflated data instances still reference it. This will almost certainly cause a crash next time we operate on one of them.
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Remember: the reading works without any problems, the crash after LabVIEW exit is what I'm concerned about
Seems to only happen with classes/objects—not the default LabVIEW Object, though
Prepending array size or different byte orders make no difference
The writing is time critical, the reading is not, in case you wish to suggest other options
Has anyone else run into this? Should I be concerned for the built applications or can this be simply ruled as an IDE problem?
Solved!
Go to Solution.
Attachments:
test_project.zip ‏16 KB
lvlog.txt ‏5 KB

Right off, if you say you can read and write lv objects, try casting your object as a lv object before saving it. The lv object is the ultimate parent of all classes.
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How to read characters from a text file in java program ?

Sir,
I have to read the characters m to z listed in a text file .
I must compare the character read from the file.
And if any of the characters between m to z is matched i have to replace it with a hexadecimal value.
Any help or suggesstions in this regard would be very useful.
Thanking you,
khurram

Hai,
The requirement is like this
There is an input file, the contents of the file are as follows, you can assume any name for the file.
#Character mappings for Japanese Shift-JIS character set
#ASCII character Mapped Shift-JIS character
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y 227,129,139
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The contents of the above file are to be read as input.
On encountering any character between m to z, i have to do a replacement with a hexadecimal code point value for the multibyte representation in the second column in the input file.
I have the code to get the unicode codepoint value from the multibyte representation, but not from a file.
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The character # is used to represent the beginning of a comment in the input file.
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Reading and writing u16 binary file to a new file

Hello all,
a very simple thing that I just don't seem to be able to figure out. I have a file containing 1024bytes of unsigned 16bit words. I can read it successfully with the right value being displayed. But then I try to write these values to a new file, I can no longer read the same value (in fact it's all grayed out 0) from the newly written file. The newly written file has the right size 1024 bytes, but I don't seem to obtain the right information. I made sure the endian are the same, little-endian.
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Thank you!
Solved!
Go to Solution.
Attachments:
read_write_binary_u16.zip ‏11 KB

I would put some wait time between the write and the read. It may be a good idea to actually close the file in between.
I have a feeling that you may not have allowed enough time to actually have the file written out before you read it again. That or since it is still open, the file pointer is at the end of the file and you are trying to read all the bytes starting at the end, which means you get nothing.
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Problem rendering certain bytes when reading binary file

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Yes but you ARE converting to a String first which you then send to the axBridge (sTemp!). Try just sending the bytes. You can easily pre-pend the "<filename>:" by sending those first.
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How to read a binary file written in LabVIEW 6.1 using VB ?

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Hello,
LabVIEW files stored in binary can take on just about any format that
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Binary file read byte unmatch

I tried to read one line of binary file as the top of the screenshot.
The result is as the left side. It shows the first part with text are correct. The ending part is not match with the raw one.
I also tried read by byte, but still the same.
Any suggestion, thanks.
Solved!
Go to Solution.
Attachments:
shot.JPG ‏48 KB

What program created this binary file?
If you can figure out how the file was created, then you can figure out how to read it.
We can't help because all you've shown are some bytes and say that some are right and some are wrong. What is the "raw one" you are referring to? What do you expect it to look like?
Message Edited by Ravens Fan on 01-26-2010 11:15 PM

Binary file data plugin : append block values to channel

I need to create a data plugin for a unique binary file structure, which you can see in the attached graphic.
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Dim sBlock : Set sBlock = sFile.GetBinaryBlock()
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I have the possiblity to read chunks from my binary file. At the end, I want to have each signal in a respective channel. I could manage to extract signals 1 and 2, as they only have one value in each block with a known byte-distance in between. How can I extract the other channels, that have 480 successive values in each block? I could probably write a loop and read the specific signal part in each block, but how can I append these parts to the relevant channels? I tried by creating a new channel and then merging them, but unfortunately functions like ChnConcat are not working in a data plugin. Any ideas?
/Phex
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Attachments:
KRE_DataPlugin_schematic.JPG ‏84 KB

Phex wrote:
@usac:
Your workaround seems to work at least for part of the file. If I loop it through the whole 1.5 GB file I am getting the DLL error "The application is out of memory". There is enough dedicated RAM available, but I guess this is x86 related.
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Otmar
Otmar D. Foehner
Business Development Manager
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National Instruments
Austin, TX - USA
"For an optimist the glass is half full, for a pessimist it's half empty, and for an engineer is twice bigger than necessary."

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Thank you for your reply,
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I want to read binary file in a specific format. There is a number at the starting of the file. That tells us where the data is starting. Suppose it says 3975, then it mean data starts at 3975. Then once I read that location I want to read data at 10bytes at a time and then convert it to numeric and display it on graph. I am attaching the file format and the current vi which I am using. please help.
Solved!
Go to Solution.
Attachments:
topo.zip ‏89 KB

Ah, the first 10 characters are a string!
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Attachments:
Read record size.png ‏12 KB

Read characters in a binary file

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