LabVIEW
array and loop
@hood1 wrote:
in total cycles variable/control when i write one, it runs once cycle that means all 3 banks/elements and then stop.when i write two,it will execute for two complete times and when i write 3,it will execute 3 complete times and so on so forth. but when i write 0,it must not execute not at all.why even when i write 0,it executes atleast 1 time and then stop?
A while loop will always execute at least once. If you want to skip it under certain conditions, place it inside a case structure.
@hood1 wrote:
in TimeTakenAry when i set 00:00:00 to all three banks.it must not execute at all.why i see some signal on the graph and why i see some execution?
Same answer as above.
@hood1 wrote:
in the inside while loop i am slowing down the while loop by using the delay of 1000. if i dont use the delay, it will execute very fast and if one element of TimeTakenAry i set to 1 hour.it will not run upto 1 hour and like i said, it finishes very fast.why?what is not correct there?
if i set time 1 hour and i dont use any delay.it must run upto 1hour.why it executes so fast and finishes early? moreover one while loop takes how much time to complete one loop.does it take 1000ms to complete one loop?
Your "simulate signal" is set to "run as fast as possible", double click it and select "simulate acquisition timing". Now remove your 1000ms delay, it has no use.
You should also learn how to use shift registers and then eliminate all your local variables. They are creating a mess. For example, there is no guarantee that the code fragment on top that calculates "Cyls2DoAry" even executes before its local variable is used inside the loop. Also, if you use a shift register initialized to zero, you don't need that "initialize to defaults" node.
Attached is a slightly cleaned up version that incorporates some of the suggestions. Modify as needed. Please ask if there are questions. 🙂
(If you set totalcycles=0, there will still be a few points on the upper graph. This seems like a LabVIEW bug and should not happen because its case is bypassed. Can anyone explain this?)
I intentionally took the controls out of the inner loop because it seems very dangerous and unpredictable to change them during a run. What if you change an entry that has already been processed? It will have no effect! What if you add an element to AmpAry but the code reads it before you have a chance to add a corrsponding entry to FreqAry?
If you really want to go that route, simply place the index arrays back inside the inner loop in my example. You still don't need any of the local variables.
Always think "data flow". Use local variable sparingly and only if really needed. Have a look at your new code fragment shown in the picture, there is NO need for locals and I show an alternative inside the red glow.
You Banks control only determines how many elements of the array is shown. It does NOT determine the size of the array, which is still size=3 even if you only display 2 elements. you must truncate/expand all relevant arrays to the given number of banks. You can use "reshape array" for this. Alternatively, you could wire the number of banks to the place where you currently read the local varable "AryBlocksNo".
If you really want to go that route, simply place the index arrays back inside the inner loop in my example. You still don't need any of the local variables.
Always think "data flow". Use local variable sparingly and only if really needed. Have a look at your new code fragment shown in the picture, there is NO need for locals and I show an alternative inside the red glow.
You Banks control only determines how many elements of the array is shown. It does NOT determine the size of the array, which is still size=3 even if you only display 2 elements. you must truncate/expand all relevant arrays to the given number of banks. You can use "reshape array" for this. Alternatively, you could wire the number of banks to the place where you currently read the local varable "AryBlocksNo".
