LabVIEW
VI Slows down after time, difficult to terminate
Allan,
first of all, your VI is way too big. Furthermore, it contains quite many parts of code which are Goldberg-Code. See attached screenshots.
Your description regarding the performance clearly indicates a memory leak or growing datastructures. The increased flashing of the harddrive led shows a growing swapfile leading to a reduced lifetime of the HD.
You have to debug the application in regard to growing datastructures.
Pazzer1 wrote:
[...]Also if I then try to stop the VI running it takes for ages to stop, in fact quite often you need to terminate labview from the task manager.[...]
Since your loops are not connected to any stop button, you have no possibility top stop the VI properly. Using the "Abort" button is a no-go and must not be used (it's only available due to "Run Continuously", a button i wish would have never been implemented)!
Some suggestions to improve performance:
- Get rid of variables
- Get rid of sequence structures
- Reduce file size
- Preallocate and reuse dataspaces. You use files instead which is slow and not good.
- Improve overall algorithms. You have many repetitions and iterative processes which are "special cases" handled in special structures.
- Reduce amount of type casts.
- Remove unneccasary logic (e.g. the outmost while loop)
hope this helps,
Norbert
vs. 
vs. 
Few points:
Your VI is enormous 4 MB is quite some code.
Most likely you have a memory lake.
Looking at your code, I see tha tyou oriniginate from a textual programming style.
Some style issues, no right to left wiring.
If you can do an operation on an array, do it on an array.
I'm not sure but I can think that the performance of the formula box in LabVIEW 6.1 isn't that optimal. There is no need for it in your code for instance in the lower left while loop where you index every element of an array and to the same calculation on the element. Perform this calculation on the full array with Lab VIEW primitives.
Another primiteve you need to know is the 'Boolean Array to Number' to convert a list of boolean to a binary number (you do this several times in a convoluted form.
Also you can stretch the 'Index Array' function to get several array elements in a row instead of using the function over and over with different (continious) indices.
My advice is to build the code for this VI from scratch using sub-vis and some design pattern.
Sorry I can't be more helpfull.
Ton
LabVIEW user groep One addition to one of my alternative screenshot:
Please note that the part in the blue circle is no good idea. Comparing floating point numbers with "equal" is never a good idea. Technically, a comparison to "greater or equal" would be better.....
