NI VSTs are capable of sending and receiving signals through the front panel connectors and the PXI trigger bus. Signals are routed between a source and destination via a path through the PXI trigger bus; there are two broad categories of routes.

The front panel connectors provide connectivity for input and output signals as well as for the control lines that send and receive clocks, triggers, and events. You can use the PXI trigger bus to send and receive events, triggers, and Sample and Reference Clocks.

Signals can be routed to and from the supported front panel connectors of your instrument. All signal routing operations can be characterized by a source and a destination. The possible signal routes for your instrument depend on the instrument, the PXI chassis, and the occupied PXI chassis slot.

When a signal is exported to a PXI trigger bus line from an instrument, only instruments in the same PXI chassis segment recognize the signal from that PXI trigger bus line. To route the signal to instruments in a different PXI chassis segment, you must establish a dynamic route or static route.

  • Dynamic route—Signal route that is specified by only the route endpoints. The actual route is determined automatically in software and is reserved and unreserved based on the based on the driver session using that route. Closing the driver session using a dynamic route releases that route.

    NI recommends using dynamic reservations and routing whenever possible.

  • Static route—Signal route that you create manually. You can implement static reservation of trigger lines in MAX through the Triggers tab.

    • Refer to your chassis documentation to determine the PXI trigger bus segments of your chassis.

    Terminal Names and Terminal Name Syntax

    A terminal name is a unique identifier that refers to a physical terminal in your system; a terminal name is fully qualified if it is an unambiguous reference to a specific terminal.

    To guarantee the uniqueness of a terminal name across multiple instruments, terminal names begin with a forward slash, followed by the name of the instrument as configured in NI Measurement & Automation Explorer (MAX), such as PXI1Slot2. A forward slash and the name of the terminal, such as PFI1, follow the instrument identifier.

    For example, the fully qualified terminal name for PFI1 on PXI1Slot2 is /PXI1Slot2/PFI1.

    Creating Dynamic Routes

    With PXI chassis that support them, dynamic routes simplify signal routing through a system by automatically choosing, allocating, and deallocating the route.

    To create a dynamic route, specify a fully qualified terminal name for the source or destination signal in your programming environment.

    Creating Static Routes in MAX

    Static routes are a way to manually designate a route on the PXI trigger bus between a specific signal source and a specific signal destination.

    Note NI recommends using dynamic reservations and routing whenever possible. If your application contains too many static routes between PXI trigger buses of your chassis, you may not be able to establish dynamic routes across chassis segments. Refer to your chassis documentation to determine the allowed number of static routes between the PXI trigger buses of your chassis.

    Complete the following steps to create static routes in MAX.

    1. Launch MAX by navigating to Start » All Programs » National Instruments » NI MAX or by clicking the NI MAX desktop icon.
    2. Expand Devices and Interfaces.
      Note If you are using a remote real-time target, expand Remote Systems, find and expand your remote real-time target, and then expand Devices and Interfaces.
    3. Select your chassis.
      The settings of your chassis are displayed on the right of the MAX window.
    4. Click the Trigger tab below the settings view.
      A table in the Triggers view shows the PXI trigger bus segments of your chassis.
    5. Configure the static route that you wish to make.
    6. Save the changes.