Use sessions, clusters, and frames to set up your NI-XNET interfaces.

Note Refer to the NI-XNET Hardware and Software Help that installs with your hardware for more detailed documentation about NI-XNET interfaces.

Sessions

An NI-XNET session represents a connection between your NI CAN, FlexRay, or LIN hardware and hardware products on the external network. Sessions include the following configuration components:
  • Port—A port in NI-XNET refers to the physical connector on an NI hardware device.
  • Interface—An interface represents the software CAN, FlexRay, or LIN connector on an NI hardware device. Use the interface name as an alias for your ports so you can avoiding changing your application if the physical hardware configuration changes.
  • XNET Database—An XNET database is a standardized file that describes embedded communication. XNET database file formats include CANdb (.dbc) for CAN, FIBEX (.xml) for FlexRay, and LIN Description File (.ldf) for LIN. For the NI-XNET interface to communicate with hardware products on the external network, NI-XNET must understand the communication in the actual embedded system.

    You can edit NI-XNET databases directly from VeriStand by launching the NI-XNET Database Editor from System Explorer.

  • Session Mode—A session mode specifies the data type (signals or frames), direction (input or output), and how your application and network transfer data. VeriStand supports the following NI-XNET session modes:
    • Signal Input Single-Point
    • Signal Output Single-Point
    • Frame Input Single-Point
    • Frame Output Single-Point
    • Frame Input Stream
    Note Refer to the NI-XNET Hardware and Software Help that installs with your hardware for more information about session modes.

Clusters

A cluster is a description of a single network, such as a CAN bus, within an XNET database. For importing frames, each port in VeriStand is associated with a single cluster within an XNET database. A cluster can contain an arbitrary number of frames.

Frames

A frame is a message that transmits across an embedded network. In VeriStand, frames are either inputs (incoming frames) or outputs (outgoing frames), and are classified according to their transmission characteristics. For example, event-triggered frames transmit only when a specific event occurs. Frames also contain information such as ID numbers and timing data that you can access through Frame Information channels in VeriStand.

You can import frames into VeriStand in either signal or raw data format. Signal format frames contain signals and raw data format frames contain channels. These terms refer to the basic data exchange unit on the network.

The specific format and characteristics of frames vary based on the communication protocol you use. Refer to the NI-XNET Hardware and Software Help for detailed information about frame formats.