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How to determine the while loop refresh/scan rate?

Hello there,

I am using Labview 8.2 on Window XP (Pentium4 CPU 2.4Ghz)
and PCI6723 card to generate Analogue signal when button on the keybord in press.

I realise that every time when i press the button on the keyboard to START or STOP the process there is some delay(around1second).
I also check on the interation of the WHILE LOOP and it show about the same referesh rate.
e
May i know which part of the system that might posisbly couse to slow down the refesh/update rate of the loop?
How can i make it response immediately(realtime or atleast as fast as possible)

Thanks in advance.


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Hi,
 
Thanks for posting your query on the National Instruments forum.
 
If you have a while loop on the block diagram that does not have a timing function (from the timing palette) within it then it will run each iteration as fast as possible. Add a wait function to see if this improves the code. Place within the while loop a Wait On Milli Second Multiple function, wire a 0 constant to it, and see if there are any improvements. What have you got going on within the loop i.e. once a button has been pressed on the front panel what happens next? is there any post calculations of any kind being performed within the loop? Perhaps you may want to consider / explore using event structures?
 
Please ensure you haven't got the execution highlighting option enabled as this slows the execution by animating the dataflow with the use of animated buble that travels from node to node along the wires.
 
You could just > right click on the iteration terminal in the while loop and create indicator to see a count for each iteration of the loop, outputted on the front panel.
 
Can you attach your VI to the discussion forum board for me to inspect your code / advise you further.
 
Kind Regards,
 
Kurt
Applications Engineer,
National Instruments UK & Ireland.
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