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Unread 27-01-2006, 14:58
Joe Hershberger Joe Hershberger is offline
National Instruments
AKA: jhersh
FRC #2468 (Appreciate)
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Join Date: Nov 2005
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Re: Labview keeps freezing

Quote:
Originally Posted by Peter H
Sometimes, I can Grab Frame OK. The rest of the time, I Grab Frame, the red LED flashes, the blue progress bar advances to the end, the progress bar disappears, a partial frame shows, and an error box appears "The application is closing because of a reported error ...". The status code is -1073807252. The status source is "VISA Read in get picture.vi>CMUcam2.vi>CMUcam2GUI.vi" I had to expand the status box to read this.
I am testing this with a USB to serial converter. The converter sends between 3000 and 4000 bytes at a time. The code handles this just fine. The error refers to a buffer overflow from your serial hardware moving the data into VISA. The data comes faster than the VISA driver can pull it out of your serial device. This means that either your computer is too slow or overworked (interrupt flooded... do you have a hard disk or CD Rom that is running in PIO mode) such that it can't access the serial port frequently /quickly enough. This is often resolved on slow machines by the hardware supporting a small amount of buffering to allow for more jitter in the driver trying to retrieve the data. If you are using a USB to Serial adapter, there's a good chance it isn't implementing a good buffering scheme or that it isn't configured well (if it's configurable). The solution may be to get a better converter. I have a USB 2.0 adapter from FTDI. It works very well.

What are you using?

-Joe
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