Solution
FPGA I/O elements are a part of the LabVIEW project. The 9870/9871 modules do not have FPGA I/O elements in the project and therefore do not support direct interaction with the I/O pins due to the RS-232, RS-485 or RS-422 protocol being used. Because of this, they cannot be selected in an I/O constant or control. To configure the I/O Method or Property Node for the 9870/9871 ports, complete the following:
- Add an FPGA Method I/O Node (FPGA I/O Panel) to the block diagram.
- Right-click the node, and choose the module and port from the Select Item menu.
- Select the method you need to use.