Linking Labview Conrtrols to Test Stand Parameters

[CAN Programmer]

I am trying to run a Teststand sequence from Labview. I was able to link all the necessary Teststand controls like Open sequence, execution display, Test UUT using the connect command invoke node. However, I am having difficulty linking labview controls to the sequence Parameters found in the sequence context. Any help on this will be appreciated.

Thanks,

Sam

[AndrewMc]

Hey Sam,

What I understand that you are trying to do is send in parameters to your sequence from the operator interface.

First of all, this is not typically a good idea due to the concept of how operator interfaces are intended.  Typically, an operator interface should be modular in nature so that the same operator interface can be used with any sequence.  Similarly, the sequence should be able to function successfuly in different operator interfaces. If you specify parameters to be sent in from an operator interface to a particular sequence, the operator interface no longer is modular and the sequence is dependent on that operator interface.

That being said, I would suggest that the best (and easiest) way to get parameters from the user into the sequence is by using a step to get the information.  For instance, a message box could pop up to ask the user for information or you could call an external code module from your sequence that gets the data. 

If you absolutely need to send in data from the operator interface, however, you can do this using custom user interface messages from the sequence.  Essentially, what happens is that the TestStand engine sends out a message to the operator interface to which the OI can respond with the parameters.  This is done using the function PostUIMessageEx and then creating a callback function to handle the events from your operator interface. 

Finally, you could always use a file as a pipe to send in data into a sequence file execution.

Hope I answered your question.

[CAN Programmer]

Andrew,

I intentionally want to have this custom user interface specific for that sequence. I only have one sequence to run for my test. I thought about having a step to ask for the parameters, however, it just doesn't have the flexibility that Labview controls have. The panel I am trying to create must have all the controls ready for the user to modify, the user hits Stat Test and that is it, no more user interaction.

I would appreciate it if you have an idea for that.

Regards,

Sam

[AndrewMc]

Sam,

As I mentioned before, UI Messages is how you would do this.  Essentially, what you would do is send a UI Message from the sequence and then handle that UI Message in the operator interface in a callback.  For instance, say that you want to know the number of loops to iterate as a setting on your operator interface.  You would send a message from your sequence named say "Give_Iterations".  In your operator interface, you monitor the UI Messages and when you see a message that says "Give_Iterations", you can set some value in your sequence context as a response to the message.

Here is an example of this type of callback:

http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=04A24417FF0933A2E0440003BA7CCD71&p_...

For general UI Message information, you can check out our developer zone documents on UI Messages located here:

http://zone.ni.com/devzone/devzone.nsf/webcategories/5D2CDEB27E67D8378625681900729242

Hope this helps!

Message Edited by AndrewMc on 09-12-2006 01:26 PM