Automation Open: the specified object can not be creatable

[jey]

Hi,

When i try interfacing TestStand with labView 7.1,the Acrivex Automation open  is throwing the error mentioned above.

The object its refering is "Sequence Context" of Test Stand.I could set other properties of TestStand from LabView 7.1 FDS,

only if  this object is created .Why is it do?.

[Caseyw]

Hello Jeyaseelan,

I would be glad to help you with this issue, and I think a good starting point would be for you to describe exactly what you are trying to do so that I can suggest solutions that fit your application. Are you attempting to call a LabVIEW VI from TestStand? Are you creating a custom operator interface?

In the most common use case for TestStand / LabVIEW interaction, you can pass the Sequence Context into your LabVIEW VI via the connector pane and then programatically perform a test and pass the results back to TestStand. You can also directly interface with the Sequence Context in LabVIEW via ActiveX calls. I think you are getting an error here because you are trying to create your own Sequence Context object rather than using a Sequence Context that was passed into your subVI from TestStand.

I look forward to your response, and I am sure that we can work together to figure this out and get your program up and running. Have a great day Jeyaseelan!

Regards,

Casey Weltzin
Applications Engineer
National Instruments

[jey]

Hi Casesy,

Thanks for your positive response.

In this application I should run a labView VI in testStand as a step that in turn  should update  ,input parametrs of other VI's(steps) for doing Numeric test and loading some file globals.

This will be Similar to the property loader of TS which reads Excel Sheet and update the variables .I have to replicate the same without using property loader.

AS you mentioned,When i pass Sequence Context object as input to VI and try running the sequence file to set some TS variales like "Local.Var1"etc,i am getting the following error.

"Unknown System error in ObjTSup.vi. ObjTSup.vi Proxy caller".

This VI is same as the  one mentioned in "Using LabView with Test Stand"referance  book  Chapter -using ActiveX for changing the static and dynamic properties of TS".Kindly let me know why this is happening and how to solve it.

With regards,

[Caseyw]

Hi Jeyaseelan,

Thank you for providing some additional information, this will definitely help me to narrow in on the issue. Which version of TestStand are you currently using? I would recommend that you start in TestStand, and create an Action step using the LabVIEW adapter. Next, right click on your step and select "Specify Module", then choose "Create VI".

This process should automatically create a template VI that you can use to access the TestStand Sequence Context from LabVIEW. In the newly created VI, you can use the Set Property Value or Get Property Value subVIs located on the functions palette under TestStand in order to write or read various TestStand local variables.

I hope this helps. Please let me know if you need any further information (or if this does not seem to work for you), and I would be glad to help you in any way possible. Have a great day!

Regards,

Casey Weltzin

Applications Engineer

National Instruments

[jey]

Hi Casey,

As suggested i have tried using Sequence Context as input and Set property VI for

changing a local variable  in TestStand.The step runs without any error but the variable value is not changed.

When i try to read "Step.Error.Msg "frpm Get Propery VI the result is same ;that is the Get Property VI is not returning

any value. Why is it so?. I am using LV 7.1 PDS and TS-3.1.

Can i use the same method for inserting Numeric limits for test steps in a TS sequence file. and updating File globals?

Kindly let me know why the above VI is not changing the value.Thanks for your help.

With regards,

[Dennis_Knutson]

You ask 'why the above VI is not changing the value' but you did not post the VI you wrote. To change a local variable, it should look something like the image below. The only function required is the TestStand - Set Property Value.

[jey]

Hi,

With this VI i could update the local variable.Now the requirement is to update the numeric limits of diferent subsequence

numeric steps.First, the VI has to find the subsequence  and the step by their names from a loader file ,then it has to update the low limit

and high limit.KIndly pass on information regarding this.Thanks Casey and Dennis for the support you'd given.

With regards

[Caseyw]

Hello,

Do you need to update the limits inside a VI, or would it be ok for you to do this in TestStand? There is a "Property Loader" step in TestStand that should do exactly what you want. Please let me know if you would like to go the LabVIEW route and I can explain that method as well.

Regards,

Casey Weltzin

Applications Engineer

National Instruments

[jey]

Hi Casey,

It is very useful if you can explain the labView approach.Since i have to read an external file to update the numeric limits,it is better to keep in VIs.Kindly let me know if i can find the subsequence names as well he step names because the step limits to be updated after finding the particular step in a particular subsequence.Thanks

[Caseyw]

Hi Jeyaseelan,

To load your steps limits from a LabVIEW VI, I would recommend taking the following steps:

1) Start from TestStand, and create a new "Action" step type named something like "Load Limits". Right click on the newly created step and select "Specify Module", then "Create VI".

2) Within your VI, load test limits from a file format of your choosing (ASCII should be the simplest). The Read From Spreadsheet File subVI should work great for this.

3) Next, you need to look up specific steps in your sequence and programatically change the limits. Right click on the Sequence Context input to your VI, and select Create >> Property >> Sequence. On the "Sequence" output of that property node, right click once again and select Create >> Method >> Get Step by Name. Enter the appropriate step name and group.

4)  Finally, right click on the "step" output of the previous invoke node, and select Create >> Method >> AsPropertyObject. Right click on the property object, and click Create >> Method >> SetValNumber. For the lookup string parameter, enter "limits.low" or "limits.high". The options should be set to 0, and the newvalue input should contain your limit value (obtained from text file).

After this, you can definitely customize the VI to meet your needs. For example, you could automatically go through every step in your sequence and detect which ones are numeric limit tests, then set the limits of those tests using data from a text file.

I hope this helps! Please let me know if you need any more information and I would be glad to assist you further. Have a great day!

Regards,

Casey Weltzin
Applications Engineer
National Instruments