NI TestStand
Using active x reference in teststand
Hi,
what you need to remember, is that you're creating objects from a class, so say you had a class of object called orange. Every time you create an object, and put a reference to it somewhere, it's a whole separate orange. This is fine if every time you create a orange object, you use it up and throw it away afterwards. You can even have lots of these objects open at once, and discard them when you've finished with them.
Now consider a class called apple which has methods that are reliant on each other. If you create an object like this, and call a method (say peel(long strip)), it will have changed something about that object. If you create another object, and call peel again with a different parameter (say peel(6 strips)), it will have performed this action on a wh
ole different object to the first one (- there is an exception to this which is the singleton server).
So it depends on how your server is supposed to work.
Can you create one object, and keep using it, or is there some dependency that requires you to create a new object of that class?
From your question, I don't think you're doing anything multi-threaded, so you could easily make one call to the Action step type, and get a reference to the new ActiveX object without calling any methods (un tick the call method checkbox). This can then repeatedly be used. You can have this as one of the first setup things your sequence does.
Another trick would be to pass the original ActiveX reference down as a parameter, and copy the creation step to the start of the subsequences, using a precondition, that if the Parameters.xxxxx == Nothing, then run the step, and create a new object, otherwise, use the one that's available.
Hope that helps.
S.
what you need to remember, is that you're creating objects from a class, so say you had a class of object called orange. Every time you create an object, and put a reference to it somewhere, it's a whole separate orange. This is fine if every time you create a orange object, you use it up and throw it away afterwards. You can even have lots of these objects open at once, and discard them when you've finished with them.
Now consider a class called apple which has methods that are reliant on each other. If you create an object like this, and call a method (say peel(long strip)), it will have changed something about that object. If you create another object, and call peel again with a different parameter (say peel(6 strips)), it will have performed this action on a wh
ole different object to the first one (- there is an exception to this which is the singleton server).
So it depends on how your server is supposed to work.
Can you create one object, and keep using it, or is there some dependency that requires you to create a new object of that class?
From your question, I don't think you're doing anything multi-threaded, so you could easily make one call to the Action step type, and get a reference to the new ActiveX object without calling any methods (un tick the call method checkbox). This can then repeatedly be used. You can have this as one of the first setup things your sequence does.
Another trick would be to pass the original ActiveX reference down as a parameter, and copy the creation step to the start of the subsequences, using a precondition, that if the Parameters.xxxxx == Nothing, then run the step, and create a new object, otherwise, use the one that's available.
Hope that helps.
S.
