First call of a Dynamic Dispatch VI in TestStand

[davidpcl]

Hi,

I've been working with LabVIEW classes and TestStand 2012 for a few months now, and it's great to see the fact that TestStand now handles LabVIEW classes so well.

However, I do have one niggle with it that I do have a solution for, but I'm kind of hoping there is a better one out there.

I've developed all my VIs to be Dynamic Dispatch which works fine, except if I have say an Initialise type of VI that gets called first TestStand won't let me pass an empty object reference into the VI's Dynamic Dispatch terminal as I get the following error :-

From a TestStand perspective this makes perfect sense, but as you cannot set the input Dynamic Dispatch terminal to be optional the only way around this is to call a VI which passes you back a reference to the required class which you can then store in the Object Reference before you call the dynamic dispatch VI - which whilst not being a problem is just a little in-elegant - just wondering if anyone out there has found a better solution to this?

Thanks,

Dave

[Al.B]

Hi davidpcl,

Unfortunately, the approach you are currently using (calling a VI which returns the class reference) is the only available method to populate the object in TestStand with valid class data.  Would you like to see the call automatically use the parent class in this case?

[davidpcl]

Hi,

I'm not entirely sure what the best option for this would be - technically there isn't an issue having wrapper VI's for the Class Constants, but it does get kind of messy in sequences when your Setup is littered with lots of calls to these VI's to initially populate the TS Object References.

One way could be that when you call a class method you have a 'First Call/New/Construct' checkbox in the module adapter settings that changes the Object Reference input to a pull down that then allows you to select the class within the hierachy that you wish to use and this then passes the default .ctl into the method much like calling a class for the first time in LabVIEW - that would be quite neat - this pull down could then default to the parent class maybe?

Dave

[Al.B]

Hi Dave,

That is an interesting feature idea.  I would recommend posting it on the TestStand Idea Exchange along with any alternative ideas you may have to address this.  Thanks for your feedback!

[davidpcl]

Have just posted this on the TestStand Idea Exchange as suggested.

Thanks,