Table Of Contents

Programming Options

    Last Modified: May 14, 2018

    You can use LabVIEW RT Express VIs, LabVIEW RT Low Level VIs, and LabVIEW FPGA I/O nodes to program the Analog Input channels.

    LabVIEW RT Express VIs

    Use the Express VIs to interactively configure the settings for the I/O channels. When you place an Express VI on the block diagram or double-click an Express VI, a configuration dialog box appears. Use this configuration dialog box to configure the Express VI. You can also configure the Express VI by wiring values to the terminals of the Express VI on the block diagram. Find the Express VIs on the Academic I/O»Control I/O subpalette on the Functions palette, as shown in the following figure:

    LabVIEW RT Low Level VIs

    Use the Low Level VIs to have more control over allocating and releasing I/O channels. For example, you can use the Low Level VIs to open or close certain channels and change the channel configuration at run time. Find the Low Level VIs on the Low Level palette, as shown in the following figure:

    Select Help»Show Context Help or press <Ctrl-H> to display the Context Help window, from where you learn the basic information about each of the Express VIs and Low Level VIs. To learn more details about the VIs, refer to the LabVIEW ELVIS III Toolkit Help by clicking Detailed help at the bottom of the Context Help window, shown as follows:

    LabVIEW FPGA I/O Nodes

    Use the FPGA I/O nodes from the FPGA palette to access the Analog Input channels on the NI ELVIS III. You can also use the FPGA I/O property nodes if needed. Channels from both banks on the NI ELVIS III can be used in a single FPGA I/O node. The I/O banks are denoted as connectors in the software. The following figure shows a VI that uses FPGA I/O nodes to read inputs from AI channels 0 to 1 on Bank A and Bank B.

    The FPGA palette does not provide any devoted FPGA I/O nodes for specific protocols such as PWM and Encoder. To access these protocols, use the LabVIEW RT VIs instead.

    Refer to the FPGA I/O Functions section of the LabVIEW FPGA Module Help for detailed information about using the FPGA I/O nodes to perform operations on FPGA targets. Refer to the NI ELVIS III section in the NI Compact RIO Device Drivers Help to learn what terminals and I/O methods and properties you can access for the NI ELVIS III. You can access these help files by selecting Help»LabVIEW Help in LabVIEW, or search for their online versions on

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