Choosing between Express VIs and Advanced I/O VIs (myRIO Module)

LabVIEW 2013 for myRIO Module Help

Edition Date: June 2013

Part Number: 373925A-01

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The LabVIEW for myRIO Module provides Express VIs and Advanced I/O VIs for you to create NI myRIO applications.

Use the Express VIs to access each type of I/O channel on the NI myRIO. You use the Express VIs for most of your applications because the Express VIs provide interactive configurability for you to determine settings for each type of I/O channel. You can configure an Express VI by setting options in the configuration dialog box that appears when you add the Express VI to the block diagram. You can double-click the Express VI to reopen the configuration dialog box. You also can configure the Express VI by wiring values to terminals of the Express VI on the block diagram.

Use the Advanced I/O VIs if you want more control over the allocating and releasing of I/O channels on the NI myRIO.

Understanding the Underlying Code of Express VIs

In the configuration dialog box of a myRIO Express VI, you can click View Code to view the underlying code of the Express VI. The code of a myRIO Express VI consists of the Advanced I/O VIs and other LabVIEW VIs.

Notice that the code of myRIO Express VIs uses Smart Open VIs instead of the Open VIs to open references to I/O channels on the NI myRIO. Smart Open VIs can open an I/O reference the first time they run and then save the reference in memory. The use of Smart Open VIs ensures that the myRIO Express VIs can run efficiently in loops because you do not need to open references to I/O channels for each iteration.

You can copy the code of a myRIO Express VI to a new block diagram and start programming with the Advanced I/O VIs. After you copy the code, replace the Smart Open VI with an Open VI because the Open VIs can open an I/O reference and pass the reference around to all other places where you need to access the I/O channel. You also need to add a Close VI to close I/O references after data operation. The following figure shows an example of modifying the code copied from the Analog Input Express VI.

Related Information

Express VIs


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