Within your embedded network, some frames may use a feature called data multiplexing (also known as mode-dependent messages). The frame specifies a single signal called the data multiplexer. A specific range of bits within the multiplexed frame is designated to contain subframes. Each subframe contains a distinct set of signals, referred to as dynamic signals. When a frame is transmitted on the network, the data multiplexer signal value selects the subframe. For example, if the data multiplexer is 0, a subframe with dynamic signals A and B may exist in the last bytes; if the data multiplexer is 1, a subframe with dynamic signals C and D may exist in the same last bytes.

Use the XNET Subframe I/O name to access properties for a specific subframe.

User Interface

The XNET Subframe I/O name is not intended for use on VI front panels or as a diagram constant. This I/O name class is returned as the value of the following properties:

  • XNET Frame Mux:Subframes
  • XNET Signal Mux:Subframe

String Use

NI-XNET determines the XNET Subframe I/O name string syntax internally. This syntax may change in future versions, so string display or formation is not recommended.

You can use the XNET Frame I/O name string as follows:

  • Open Refnum: LabVIEW can open the XNET Subframe I/O name automatically. Wire the I/O name to a property node or VI, and the refnum is opened prior to the first use.

Refnum Use

You can use the XNET Frame I/O name refnum as follows:

  • XNET Subframe Property Node: The XNET Subframe property node provides the information such as the data multiplexer value for the subframe and the list of dynamic signals within the subframe.
  • XNET Database Create (Dynamic Signal) VI: If you are creating a new database, call this VI to create a new XNET Signal within the frame. This instance creates a dynamic signal contained within the subframe. To create a static signal that exists in all frame values, call the XNET Database Create (Signal) VI using the parent XNET Frame (not the subframe).