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XNET Flush (G Dataflow)

Last Modified: November 2, 2017

Flushes (empties) all XNET session queues.

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session in

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

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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

With the exception of single-point modes, all sessions use queues to store frames. For input modes, the queues store frame values (or corresponding signal values) that have been received, but not obtained by calling XNET Read. For output sessions, the queues store frame values provided to XNET Write, but not transmitted successfully.

XNET Start and XNET Stop have no effect on these queues. Use XNET Flush to discard all values in the session's queues.

For example, if you call XNET Write to write three frames, then immediately call XNET Stop, then call XNET Start a few seconds later, the three frames transmit. If you call XNET Flush between XNET Stop and XNET Start, no frames transmit.

As another example, if you receive three frames, then call XNET Stop, the three frames remains in the queue. If you call XNET Start a few seconds later, then call XNET Read, you obtain the three frames received earlier, potentially followed by other frames received after calling XNET Start. If you call XNET Flush between XNET Stop and XNET Start, XNET Read returns only frames received after the calling XNET Start.

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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