How to see LV object parameters in Teststand during debugging

[GoKu25]

I am developing a Teststand program in conjunction with a LabVIEW OOP. I create objects(instruments like DMM, SA) in TS, configure and do measurements. I have a requirement to view the Objects' parameters during debugging- for more clarity, consider a step for making a measurement and I place a breakpoint in it. When the control reaches that step and before you step into the VI, I would like to see, maybe  a window pop up where the parameters are displayed. Is this feasible in Teststand? If not, please recommend alternate ideas

[MelanieE]

Hi GoKu25,

due to encapsulation you can not view the properties of an object in TestStand because TestStand is not a class member.

However you can create a custom probe for LabVIEW that can show you the object properties as soon as you jump into the VI. The following link will show you how to create such a custom probe:

Creating Custom Probes - LabVIEW 2017 Help - National Instruments
http://zone.ni.com/reference/en-XX/help/371361P-01/lvhowto/creating_custom_probes/

Another alternative may be Xcontrols. You could see any value changes on the front panel of your VI but they include the ability to make changes inside of the object data which is a violation of encapsulation. Detailed information about this topic can be found under the follwoing link:

Creating New Front Panel Objects with LabVIEW XControls - National Instruments
http://www.ni.com/tutorial/3198/en/

Best,

Melanie

[GoKu25]

Hi Melanie,

Thanks for the reply. 

 An object can be passed from LV to TS as an Object reference and  be sent back to LV  again but it's properties can't be read. Is that right?

Xcontrol sounds a bit complicated at the moment.  

Is there a way to start a VI when the execution is suspended at a breakpoint without even stepping into it.

I was thinking, I could start a Asynchronous VI that pops a window and displays a list of objects-in-memory in a list and clicking on an object would display the properties. 

P.S. I have a requirement that the TS developer, after setting a breakpoint and the execution suspends waiting to be stepped into, should see the objects in memory and it's properties in TestStand without stepping into the VI and this functionality should occur only during debugging. I doubt if this could be done solely in TS

[MelanieE]

Hi GoKu25,

yes, you are right. It is not possible to view the properties of an object, even not from VIs that are not class members. So even the last suggestion won't work that way. If you want to take a look into object properties, the module looking into it must be class member due to encapulation.

Best,

Melanie