I did something that sounds very similar a couple of years
ago. The temperature profiles I was working with employed specific dwells,
ramps etc. in the cycle, which were generated by the engineering department as
part of an ISO9000 design process. So we had to employ these curves. (I managed
to do some value add in the whole process to guarantee / achieve
traceability). Your curves might have to follow a specific equation that you could use and calculate the limits at each time interval.
In my case, I had the engineers export the calculated Excel as text files which are used as basis for the limit curves (there was also a nominal cycle curve). These were then loaded into a multi dimensional array (2D) before
the start of the cycle. The measured data was stored in the same 2D array
during the cycle. The whole lot could then be graphed quite readily. Limits
were easy to check because the position in the array represented a specific
part of the cycle and just needed reading across the array at the same index for the limit
checking. I guess you would have about 1M worth of data so it should not be a
problem for one cycle. One word of caution, our batch had to finish processing
otherwise the whole batch had to be thrown, at considerable cost. So the system
had power protection generators. But I also wrote the data to hard disc
(mirrored) during the process every couple of minutes for security, it has saved the day a few times! I also arranged for XCOPY to run every night to move the new data over to a server (check out the options for XCOPY).
I can't say it was based on a specifically pre-written example but the
inspiration for it was the Frequency Analysis Of A Filter Design.VI. In
LabVIEW 8 this example has evolved a bit since I first saw it.
Try searching with the keyword LIMIT in the example VI's there are some cool
examples using the Express blocks as well.
