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XNET Stop (G Dataflow)

Last Modified: November 2, 2017

Stops communication for the specified XNET session.

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session in

The session to stop. This session is selected from the LabVIEW project or returned from XNET Create Session.

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scope

An input that describes the impact of this operation on the underlying state models for the session and its interface.

Normal (0) The session is stopped. If this is the last session stopped on the interface, the interface is also stopped. If any other sessions are running on the interface, this call is treated just like the Session Only scope, to avoid disruption of communication on the other sessions.

This is the default value for scope if it is unwired.

Session Only (1) The session is placed in the Stopped state . If the interface was in the Started or Running state before this node is called, the interface remains in that state and communication continues, but data from this session does not transfer. This scope generally is not necessary, as the Normal scope only stops the interface if there are no other running sessions. This operation sends the command to stop the session, but does not wait for the session to be stopped. It is ideal for a real-time application where performance is critical.
Interface Only (2) The underlying interface is placed in the Stopped state . This prevents all communication on the bus, for all sessions. This allows you to modify certain properties that require the interface to be stopped (for example, CAN baud rate). All sessions remain in the Started state. To have multiple sessions stop at exactly the same time, first stop the interface with the Interface Only scope and then stop each session with either the Normal or Session Only scope.
Session Only Blocking (3) The session is placed in the Stopped state . If the interface was in the Started or Running state before this node is called, the interface remains in that state and communication continues, but data from this session does not transfer. This scope generally is not necessary, as the Normal scope stops the interface only if there are no other running sessions. This operation waits for the session to stop before completing.
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error in

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Default: No error

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session out

An output that is the same as session in, provided for use with subsequent nodes.

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error out

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Description

Because the session is stopped automatically when cleared (closed), this node is optional.

For each physical interface, the NI-XNET hardware is divided into two logical units:

  • Sessions: You can create one or more sessions, each of which contains frames or signals to be transmitted (or received) on the bus.
  • Interface: The interface physically connects to the bus and transmits (or receives) data for the sessions.

You can stop each logical unit separately. When a session is stopped, all contained frames or signals are placed in a state where they are no longer ready to communicate. When the interface is stopped, it no longer takes data from sessions to communicate with other nodes on the bus.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Supported

Web Server: Not supported in VIs that run in a web application


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