SignalExpress User-Defined Steps with LabVIEW 8.x VIs that Include DAQmx

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SignalExpress User-Defined Steps with LabVIEW 8.x VIs that Include DAQmx

Primary Software: LabVIEW Signal Express>>Development System
Primary Software Version: 1.1.1
Primary Software Fixed Version: N/A
Secondary Software: LabVIEW Development Systems>>Base Package

Problem:
I am using a LabVIEW 8.x VI that contains DAQmx function calls as a user-defined step in SignalExpress. When adding my VI as a user-defined step, a "Failure Opening VI" error is returned in SignalExpress. Why is this occurring?

Solution:
For a VI built in LabVIEW 8.x containing DAQmx function calls to work within SignalExpress as a user-defined step, it must be saved as a reentrant VI within an LLB file. In addition to your VI, that LLB file must also contain the DAQmx functions contained in the vi.lib directory. To serve as an example, the following steps define how to create a LabVIEW 8.0 VI that performs an analog output task to be used in SignalExpress as a user-defined step:

Create a new blank project in LabVIEW 8.0. In the Project Explorer window, right click on My Computer and select New»VI.
Add a DAQ Assistant Express VI on the block diagram configured to perform an analog output task.
Identify the control on the connector panel of the VI. Open the VI's front panel and right-click on its icon in the upper-right portion of the window. Select "Show Connector", which will display the VI's default connector pane. Associate the empty connector pane terminal with the control on the front panel:
1. Hold the cursor over the connector pane terminal that you would like to associate with a front panel object and left-click it (best programming practice dictates that you always try to keep inputs on the left side of the connector pane and outputs on the right).
2. The connector pane terminal that you are operating on should now be filled black.
3. Now hold your cursor over the control that you would like to associate with the blackened connector terminal and left-click it.
4. The connector pane terminal that was filled black should now be filled with the color corresponding to the data type of the control/indicator with which you associated it, and this indicates that the connector terminal has now successfully been created.
Configure the VI for reentrant execution by going to File»VI Properties and selecting the Execution Category.
Save the project and VI. Right click on Build Specifications in the Project Explorer window and select New»Source Distribution.
In the Source Distribution Properties dialog box, go to the Distribution Settings page. Select the Packaging Option "Single Destination" and uncheck "Exclude vi.lib". Modify the Distribution destination directory such that the final destination location ends with a *.LLB extension, and select "Yes" at the prompt. An example would be C:\Documents\AnalogOutput.LLB

Note: In LabVIEW 8.2, the "Exclude vi.lib" is found in the Additional Exclusions page, not the Distribution Settings page.
Click the Build button. The source distribution will contain your VI as well as all the DAQmx VIs in a single LLB file. Open SignalExpress and use the VI contained within the LLB file as a user-defined step.