step using old measurement data

[Hoss183]

I have a strange problem.

I have a test sequence which runs correctly for several previous steps, using VI's

Then it comes to 2 steps test (multi numeric) which calls the same VI (once in each step), output of VI is a 12 element numeric array.

Now these steps are failing because the measurement used seems to be old data (i.e. the first step is using the measurement from that VI from the last sequence run, and the second step is using measurement from the previous step)

I know the VI is returning the correct data, beacuse i put in a break point & watched it.

And i know that VI data is initialised before returning the measurement.

Its really crazy. None of the previous steps using other VI show this problem. And i can call the VI in question manually and it returns correct data.

Any ideas?

[RayFarmer]

If you are using the same VI's on different steps and dont unload the step after its completed, this willl mean your VI stays in memory and any values on controls and indicators will remain from previous calls unless ofcourse you pass new data on the all the controls, or initialise any unused controls. Like wise on indicators make sure you initialise these, so for instance if you dont empty the output array or completely over write the indicator with the same number of elements as in previous calls you may see old data pass back to Teststand.

Do you pass the error cluster out, maybe you are getting a error and if you are not passing this back to teststand maybe you are seeing old data because of an unseen error.

Just a couple of thought.

[Hoss183]

Hi Ray, thanks for your reply.

In fact i've solved the problem, it was due to a silly mistake in sequence inside the labview VI.

I tried selecting "load dynamically' and 'unload after step executes' for these steps while i was trying to locate the problem

But actually a general question - If i am reusing the same VI, should i be using those settings on all steps for security?

[RayFarmer]

Hi,

No I dont think it's neccessary in most cases, providing your VI can handle the situation where it always starts in a known condition.

[RayFarmer]

Hi,

This might prove useful regarding Load/Unload Options.