multiple numeric limit test with unknown number of elements

[tman]

I want to run a test that measures the ouput frequency of a device at serveal points as it sweeps across a band. It is only known at run time how many points will be tested. The device will sweep from START_Freq to STOP_Freq at a given Freq_Increment_Size. I was going to use a Multiple Numeric Limit Test step to measure all the frequencies. What I can't figure out how to do is assign the test limits for each measurement. Since the number of measurements and the Start_Freq is only determined at run time, I can't just edit the limits for each one manually. So, how would I assign limits to Measurement[0] through Measurement[n]that is equal to
(Start_Freq + (Freq_Increment_Size * X)) where X=0 to Num_Measurements?

Thanks

[Kevin L]

Hello,

I think the best solution for you is to create a custom step type which will accept arrays for the Limits and the Results of the step. Then the size of these array can be determined at runtime. So, I created a custom example for you in TestStand 3.1 and LabVIEW 7.1 which shows this custom step type. This example will perform a numeric limit test on an array of data. It will then compare each index of the Limits arrays with that index of the Result array. If each index of the Result array is within the Limits array the step will pass; otherwise the step will fail. Also, this example includes a PostStepVI which will need to be in one of your search directories. I hope that this information helps you out.

Regards,
Kevin L.
Applications Engineer
National Instruments