Slow graphics display: 2-D and 3-D graphs...

[vitamin0]

I am having some serious difficulties with the graphics update rate on my VI. My application calls for acquiring 26 channels of data from two DAQPad-6020E USB devices (13 channels/device) at sampling rates of less than 100 Hz. The sampling is not the bottleneck. Ideally I wanted to show three 3-D graphs that updated at 30Hz, but I can't get anywhere near that, and I start to get backlog in the devices. So i removed the 3-D graphs and resorted to simply showing some 2-D graphs. I still have slow update rates. So I finally gave up and resorted to simply showing the values with numeric indicators. Those indicators update as fast as the data is coming in (which can be very high in this case, without backlog). An ex
ample of the problem: I have a numeric display for a signal that is either zero or one, and it updates immediately upon a change. An LED attached to the very same signal updates about a second after the numeric indicator changes! That is unacceptable lag, and the numeric indicators are not a pleasant way of viewing the data.

I am running all this on an older laptop, so maybe I am outta luck. My system: Win95, Labview 6.0.2, Dell Inspiron 7000, Pentium II, 266 MHz, 64MB RAM, ATI RAGE Mobility - P video with AGP 2x, 4M/8M SGRAM.

Do I need to upgrade to a new system? We tried running this on a newer desktop model with much faster CPU and supposedly better graphics card, and it was not significantly faster graphics updating. Are there video cards that may work better, such as those that support OpenGL in hardware? Does anyone have any recommendations? Would using the "classic" (pre-version-6) indicators work better?

Thanks for your help!

jeff

[emag]

I had this problem. 3D-Graph in LabView works always VERY slowly. I use the
external fortran-program for three-dimensional visualization. This program
have direct access to OPENGL and receives data from the LV-program with the
use of the text file. It is primitive but is quick or VERY quick.
It is possible to load 3D-demo of deformable objects
(www.mpei.ac.ru/homepages/emag/download/3dopengeo/DEMO/3ddemo.exe).
Here is the add - information: www.mpei.ac.ru/homepages/emag/eng

Y. Kulayev

[markwysong]

I've had some other applications which had similar problems. To check your video, set the number of colors down to 256. The more pixels the card has to redraw as a result of new data, the longer it takes. Therefore, dropping the colors should help. (It made a significant difference for me.)

Mark