Best way for fast plotting on a graph ?

[gasma1975]

Hi all,

I'm using Labwindows CVI 6.0 full release and W2K. I'm acquiring data from my LPT1 (parallel port) at a rate of 25000 samples/s in a circular buffer. This is done in a thread, my other thread is for the plotting on a CWGraph, but the plotting seems to be slow, I always overrun my circular buffer. Is there a way to do fast (almost real time) plotting ?, should I use the basic graph from CVI, is it faster ?

[Chris Matthews]

Yes, the CVI native graph should be faster. There is less overhead without the ActiveX calls to a separate component. How fast are you wanting to go? (Plot function calls per second). There are a lot of considerations to how fast you can go. Is it a strip chart or a graph? In a strip chart the scrolling mode can make a big difference. Also, are you auto scaling? That can make a big speed difference as well.

Best Regards,

Chris Matthews
National Instruments