VI Returns Control to Sequence Before it is Finished

[Jim_Flip]

HI,

I have an Action step calling a VI that can take up to 35 seconds to complete and TestStand  doesn't wait for it to complete and goes to the next step. Some of the data is there before other data is ready. Is there any way to control how long a step will wait?

TIA,

Jim

TS 3.5

LV 8.6

[~jiggawax~]

This doesn't sound right.  What settings and properties do you have set for the step?  Also do you have any Time Limit Settings in the Station Options?  A step should not complete and move to the next step until that VI has finished and relinquised control back to TS unless you have it set to run Asynchronously.

If none of this is helpful maybe you can post an example or something.

Regards,

[Jim_Flip]

Thanks for the response Jigg! I thought I was crazy until you made me feel better about the next step not getting control until the previous VI was finished. I'm by no means a TS guru, but I'm not a novice either.

I don't have any Time Limit Settings in Station Options and the VI is not running asynch. I have attached a troubleshooting version of the Sequence. It is not prettty, but it shows the settings. Maybe you can spot something I can't...and believe me I have looked for hours. The problem is the call to Read Camera Header in the subsequence. The call to the VI only takes 8 seconds (most of the time) and by then the execution is already gone another 5 steps and writes trash data to the file.

[RayFarmer]

Hi,

The problem must be in the VI its self. As you are using TS3.5 I dont believe running a VI Asynchronously was available until version 4.0 therefore the only way would be to run a VI in a SequenceCall and set this to run in a new thread or execution. Are you doing this and not set it to wait.

( I can only look at your sequencefile via a text editor at the moment)

What are you doing in the VI, can you provide a screen shot

Regards

Ray Farmer

[Jim_Flip]

Hi Ray,

The VI is not in a new thread or execution, so it should wait. I am not sure how the VI itself could cause the problem. I was under the impression it should always wait for the VI execution to terminate. It does have a large possible latency of up to 35 seconds, but I wrote a virtual version and it works correctly.

The VI is too large to post a screen shot and not finished enough to post here 😉 

Thanks for the feedback!

Jim

[Jim_Flip]

Hi All,

It now seems that I did not have any problem but my understanding of the program. The VI did finish before passing control back to the sequence. It was extremely hard to recognize that it was indeed finished.

Many thanks to Jigg and Ray for steering me in the right direction!

Slightly Embaarassed 😉

Jim