© National Instruments Corporation2-1LabVIEW LEGO MINDSTORMS NXT Module2Extensions to LabVIEWThe NXT firmware supports various I/O devices for which LabVIEW has no built-in interfaces. Examples include motor outputs, sensor inputs, and the NXT display. To support these devices, the module provides extensions to LabVIEW in the form of five classes of generic reference numbers, or refnums, and an associated set of properties and/or methods with each class of refnums. Each property or method loosely corresponds to a particular piece of the I/O interface provided by the NXT bytecode interpreter.The module provides the following five classes of generic refnums:•NXTInput•NXTOutput•NXTOutputMulti •NXTSyscall•NXTDynamicSyscallThe module palettes provide type definition controls of each new refnum class.You can use the NXTInput, NXTOutput, and NXTOutputMulti refnums with Property Nodes to expose the interfaces to input and output devices. Connect any of these refnums to a Property Node, and then resize the Property Node to expose as many properties as you need to read or write.Each Property Node must include an input to specify the physical port(s) to access. Refer to the specific Port or PortList property descriptions for more information on each port. Each additional Property Node line corresponds to some configuration field, such as device mode or measured value, for the specified port(s).You use the NXTSyscall and NXTDynamicSyscall refnums with Invoke Nodes to expose system-level methods for access to various other features of the NXT firmware. Use the NXTSyscall refnum with methods that the LabVIEW LEGO MINDSTORMS NXT Module provides. Use the NXTDynamicSyscall refnum with custom methods that you create.