Multi Plot XY Graph. One Plot Envlope, checking to make sure the other plot falls within the enclope plot

[Rawly]

Hi Guys

Have a problem with XY graphing, I have 5 xy samples that define an envlope (one plot), samples need to be checked to make sure they are within the selected envlope.

Any Ideas ?

[IanW]

Hi Rawly

Do a serch examples for Limit Testing, there are examples there which show you how to create your limit envelopes and check if your data falls within limits.

The basic vi's are under analyse, waveform monitoring (LV6.1).

[Rawly]

Hi Ian

Thanks for the reply, ive been looking at these examples, the problem ive got is that its an XY plot and the envelope goes back on itself.

I have 4 xy samples that make up a envelope, 0,0 3,6 9,9 3,0

The last sample takes the plot back to x=3 y=0. The limit testing looks like it needs a uniform time axis i.e. the samples can not go back on themselves.

What i am trying is Interpolated Data, to give me more points between each envelope sample. Its really just trying to find if the sample data intersects the envelope line.

Any other ideas ?

Thanks

[IanW]

Can you split the 4 xy point for your envelope int two envelopes:
Upper Limit 0,0 3,6 9,9
Lower Limit 3,0 9,9 (or maybe 0,0 3,0 9,9 if you need to start at x=0)
Then in your limit check connect both upper and lower envelopes.

Have a look at the attached vi, it's not very tidy and there may be a problem with the number of samples in the various arrays, it may give you some ideas to try.

[Rawly]

Hi Ian

Thanks for the vi, its very similar to the one i have produced, the limit check works great, thanks for the help

Rawly