Re : Re: labview waveform data type in teststand

[krikrists]

Hello,

I'm using TestStand 3.1 with Labview 8.0 and I'm doing generation and acquisition in the labview module. My problem is: I'm trying in my labview VI to acquire a data as a digital waveform data type and I wanna save that in a TestStand variable by using the TestStand Box :"Set property value". First of all I'm wondering if it's possible. and if yes how can I do that.

It might be possible because in TestStand 3.1 you can create a variable of Labview digitalwaveform type.

Thanks in advance for your help

[AllenP]

You can do this by passing the data back through the connector pane.  You can then use the Labview Digital Waveform type in TestStand.  If you cannot use the connector pane to pass the information back, you must get the individual components to pass back to TestStand and use the API methods for each component.

One thing to note is that TestStand 3.1 does not support LabVIEW 8.0.  Some parts may work correctly, but you may run into future problems using this combination.  You will not be able to use the TestStand Deployment Utility to deploy LabVIEW 8.0 VIs from TestStand 3.1.  TestStand 3.5 supports LabVIEW 8.0.

Allen P.
NI

[krikrists]

I don't quite understand what you mean by me passing the data through the connector pane. I attached a print screen with this mail. As you can see for some variable as numble of sample read, error sample number... I save them in a TestStand FileGlobal by using the "set property value" box of the TestStand palette.

Is there anyways to do that with the acquired data which is a Waveform data type? if it is what you answered then I didn't get what you asked me to do.

Thank you for your help.

[AllenP]

Based on the design of your VI, you really don't need to call any of the TestStand Set Property VIs.  These VIs are only needed if you need to send it to a variable that is set at run time, you need to send values while the VI is running, or you are not using a code module to set the values.  They were also more neccesary in TestStand 2.0 when you couldn't use LabVIEW's connector pane.  You just need to create an indicator for every value you wish to send back to TestStand.  Go to the Front Panel, and right-click the icon on the upper-right corner of the VI, and choose "Show Connector".  You can wire the indicator that you wish to pass back to TestStand to a node on the connector pane.  The VI you sent has only 6 panes, but you can also choose a larger pane to pass more parameters back.  When you configure your VI using Specify Module inside of TestStand, you can choose to send each of the parameters to a Local or Global variable by typing the lookup string, such as FileGlobals.X.

Hope this helps!

Allen P.
NI

[Mackemann]

Hi Allen,

    lookng for an answer to my problem I've read this forum thread. Following, we have done an acquisition with LV 7.1 and "DAQmx Read.vi" function that returns an array of Waveforms. We want to pass this waveform values to TS 3.1, afterwards we will read it from an Step Type that it will make the waveform analysis. We use the Property Object SetValVariant and it returns an error (see picture). Before executing this we have connected also this Waveform to the output connector pane in order than que we insert the LV Action in TS we can save this waveform in the variable we need. Until this point everything seems to work OK.

    As this waveform is not a standard variable such string, numeric, array and so on, we create a Custom Data Type (see picture) from the Specify Module. This should make both data coming form LV and TS compatible, but it doesn't work. Some idea how to solve this problem?

Thanks,

Angel

[Dennis_Knutson]

I have no problem creating an action step that returns an array of waveforms to TestStand. Here's a sequence and VI. I don't understand the comment about the property object or what you could possibly be using that for. As already mentioned, you just need the connector pane.

[Mackemann]

Hi Dennis,

   the example you propose works ok, but this was not our real problem. I attach you a picture with the "Property Object" that returns us the error. We'd like to save directly the Waveform Data in the "Location Result" variable.

Thanks.

[AllenP]

The SetValVariant method is useful for passing arrays to TestStand, but will not work for other data types, such as the Waveform Data Type.  If you do not want to connect the Waveform to the Connector Pane, you will have to extract the various parts of the waveform, and call SetValXXX on these components.

Allen P.
NI

[Mackemann]

Hi Allen,

   is this the unique method? Would it be possible to do this in a PostStep or PostExpression?

Angel

[Dennis_Knutson]

I don't understand the reasoning behind use the TestStand API to set the value of the waveform array but you can do everything in the step. You don't need a post expression.