Labview timing problem

[Paul_2003]

I'm kind of stuck with a bit a problem in Labview 7 (base ed.). I've got a PCI-6036E that can sample at 200KS/s with a 24bit onboard timer.

I've got to set up an experiment that monitors a current indirectly through a potentiostat (1A = 1V scale). The program needs to integrate the current/voltage with respect to time until it reaches a specific value and then tells the program to generate an analogue signal output (this will over and over)

Surely it should be quite straight forward to read a voltage on one of the inputs, summing this value in a loop until this limit is reached, then outputting a voltage.

The problem is I'm not quite sure how to approach this considering that I need a time interval of the loop to be ~1-10 microseconds.


Many thanks,

Paul

[EdDickens]

The only way you're going to get microsecond loop speeds is to move up to the new FPGA board, currently only available for PXI.

Under Windows, or any GUI OS for that matter, loop speeds and determinism get shaky in the double digit milli-second rates, and anything less than 10 mS is really not reliable. LabVIEW Real Time can get much better loop timing, but you're still limited to the milli-second rate as the CPU can't process any faster than that.

Anything running on the FPGA is running in hardware and extremely fast and deterministic loop times are possible. I�ve run them in the nano-second range just doing some testing. Data from applications running on the FPGA can be accessed from La
bVIEW Real Time, LabVIEW or both so you can control what�s going on.

Your best bet would be to either call NI or your local NI rep and have them get you some more info.

Ed

[Albert.Geven]

Let your anlog IO card do the sampling with microsecond resolution and read that array of data into labview while measuring.
It is easy to buffer this data and do a calculation afterwards or even in real time on a windows machine. As long as you let your card do the timing.
A lot of buffered io examples are available and if you don't find a correct one mail me with what you have tried and maybe I have a simpler example..

[Tom_Hawkins]

But the questioner needed to generate an output as soon as the integral of the input passes a certain value. Sounds like a job for old-fashioned analogue electronics to me!