Environment: LabWindows/CVI 6.0, Windows NT
We're downloading a BUNCH of data to a custom hardware device over the parallel port using inp()/outp(). The download loop, which looks something like:
for (i=0; i<2400000; i++) {
Byte = Data[i];
outp(Byte);
}
takes 30 seconds to execute. If we comment out the "outp" line, the loop is instantaneous, so all that 30 seconds is tied up in the call to outp(). The same piece of code, when compiled with Microsoft C++ using a piece of freeware called GiveIO for low-level access, takes 4 seconds to execute.
Is there any way to speed up the native CVI outp() function?
We can't use VISA, because our hardware can't be configured the way VI
SA would like.
Any suggestions greatly appreciated. I'm afraid we may have to ditch CVI and try to use GiveIO instead, if we can't resolve this speed issue.
Thanks,
-Michelle