LabVIEW
save data string in binary file
Hi Vicens,
yes, using 'Write Chars to file' is not optimal.
First: try to collect data before writing to file instead of writing each small message seperately. For instance you can collect messages upto 1 million chars and write the resulting string. Avoid 'concat string' (same as 'build array') due to memory handling issues. Better use a 'replace array subset' approach.
2nd: Try to open your data file first (before data aqu starts), then write the data using any binary method. Close the file after daq stopped. 'Write chars to file' will open and close the file each time you call the function...
yes, using 'Write Chars to file' is not optimal.
First: try to collect data before writing to file instead of writing each small message seperately. For instance you can collect messages upto 1 million chars and write the resulting string. Avoid 'concat string' (same as 'build array') due to memory handling issues. Better use a 'replace array subset' approach.
2nd: Try to open your data file first (before data aqu starts), then write the data using any binary method. Close the file after daq stopped. 'Write chars to file' will open and close the file each time you call the function...
Hi Vicens,
in LV8.2 you can wire any datatype to 'Write to Binary', including string and U8-array. First convert your array of strings to one long string by using 'concat string' or even better collect your messages in one long string instead of creating an array...
In LV upto 7.1 you can use the 'Write File' function. Here you can also wire a string or an U8 array. For generating the data the same applies as above!
Just have a look inside the 'Write characters to file' function to see how it's done!
in LV8.2 you can wire any datatype to 'Write to Binary', including string and U8-array. First convert your array of strings to one long string by using 'concat string' or even better collect your messages in one long string instead of creating an array...
In LV upto 7.1 you can use the 'Write File' function. Here you can also wire a string or an U8 array. For generating the data the same applies as above!
Just have a look inside the 'Write characters to file' function to see how it's done!
Actually, the limit for LV7.1 is "normally" 2GBytes, since LV7.1 uses 32bit signed pointers for file access. However, there is an easy way around this in WinXP, provided your file system is NTFS, not FAT32 (it is, isn't it 
). You can find complete directions and code examples in the tutorial Managing Large Data Sets in LabVIEW. Click on chapter 5 in the table of contents to take you to it. Note that the HDF5 utilities mentioned in that tutorial make an excellent binary file storage mechanism, although the learning curve is more than a bit steep.
). You can find complete directions and code examples in the tutorial Managing Large Data Sets in LabVIEW. Click on chapter 5 in the table of contents to take you to it. Note that the HDF5 utilities mentioned in that tutorial make an excellent binary file storage mechanism, although the learning curve is more than a bit steep.