LabVIEW
How to read and graph an .lvm file?
Hi Jack,
Does your .lvm file consist of multiple 400 sample segments (you mentioned 400 samples was one write iteration)? If so, I'm guessing you want to read and concatenate all of these segments into a single graph plot. Placing the "Read from measurement file.vi" within a while loop would be the simplest way of doing this as it will read the subsequent segments on each iteration, however, you need to monitor the EOF (end of file) boolean output from the VI to determine when to exit the loop. That way you won't receive the error.
It's also worth baring in mind that using a while loop in this manner when the file size is unknown will result in a performance/efficiency hit memory wise, but this is only generally a problem when dealing with extremely large files for which the .lvm format isn't designed for.
Hope that helps,
Paul
Hi Jack,
Glad to hear you made some progress with loading the file.
I'm afraid with regard to the loading speed, there is little else you can really do. You are always going to have a loading delay when retrieving an entire files worth of data into memory. One thing that would be worth trying is specifying a smaller segment size within the read. I've done some bench marking with sample data and it appears this can reduce the loading time by half, most likely because the memory manager can deal with smaller chunks of memory rather than juggling several large contiguous pieces.
All the best,
Paul
