loop timing in LabWindows

[Lei Dai]

Greetings,

I am currently exploring ways to implement a waveform generator for the purpose of driving MRI gradient coils. I have looked at both MATLAB and LabVIEW and was wondering if LabWindows might be a more efficient tool. I know that engineers at GE Medical Systems have accomplished what I'm trying to do with LabWindows but I have no specific information about their work. I'm just trying to find out they chose LabWindows, if for any good reason at all. The core of my inquiry is regarding real-time loop timing. What kinds of performance in terms of software timing can LabWindows achieve? Is it possible to get speeds of up to 10Mhz without any hardware timing? ...or is the OS performance upper bound reached long before this?

Thanks in adva
nce for yor help.
Lei

[Chris Matthews]

Oh yes, the upper bounds of the OS software timing is 1ms (or 1KHz). Hard to believe, but true. That is the lowest resolution clock in the Windows OS. You will have to use hardware timing for anything faster than this regardless of programming tool. In choosing your programming tool, the main question is in programming preference, not efficiency. LabVIEW versus LabWindows won't matter much in speed, it is more a question of do you prefer graphical programming or C programming. If you prefer C programming, then choose LabWindows/CVI.

Best Regards,

Chris Matthews
National Instruments