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IviSwtch Configure Scan List [SCN] (G Dataflow)

Last Modified: September 7, 2018

Configures the switch module for scanning.

Use the IviSwtch Configure Scan Trigger [SCN] VI to configure the scan trigger. Use the IviSwtch Initiate Scan [SCN] VI to start the scan. If the switch module is currently scanning through the scan list, this function returns IVISWTCH_ERROR_SCAN_IN_PROGRESS (0xBFFA2006) without configuring the scan list. If the given scan list string contains incorrect syntax, this function returns IVISWTCH_ERROR_INVALID_SCAN_LIST (0xBFFA2002). If the given scan list string is empty, this function returns IVISWTCH_ERROR_EMPTY_SCAN_LIST (0xBFFA2004).

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Note  

This VI is part of the IviSwtchScanner [SCN] extension group.

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instrument handle

The instrument handle that you obtain from the IviSwtch Initialize Node. The handle identifies a particular instrument session.

Default: None

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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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scan list

String that specifies channel connections and trigger conditions for scanning. Pass the scan list you want the instrument to use. The driver uses this value to set the IviSwtch>>Scanning Configuration>>Scan List [SCN] property. After you call the IviSwtch Initiate Scan [SCN] Node, the instrument makes or breaks connections and waits for triggers according to the instructions in the scan list.

Scan List Special Characters

To create a path between two channels, use '->' (a dash followed by a '>' sign) between the two channel names.

Example: "CH1->CH2" instructs the switch to make a path from channel CH1 to channel CH2.

To break or clear a path, use a '~' (tilde) as a prefix before the path.

Example: "~CH1->CH2" instructs the switch to break the path from channel CH1 to channel CH2.

To wait for a trigger event, use a ';' (semicolon) as a separator between paths.

Example: "CH1->CH2;CH3->CH4" instructs the switch to make the path from channel CH1 to channel CH2, wait for a trigger, and then make the path from CH3 to CH4.

To tell the switch module to create multiple paths simultaneously, use a ',' (comma) character as a separator between the paths.

Example: "A->B;CH1->CH2,CH3->CH4" instructs the scanner to make the path between channels A and B, wait for a trigger, and then simultaneously make the paths between channels CH1 and CH2 and between channels CH3 and CH4.

Interchangeability

Users who want to achieve interchangeability should use a virtual channel name. The virtual channel name should be sufficiently specific to the test system such that it is unlikely to conflict with a physical channel name.

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scan mode

Pass the scan mode you want the instrument to use. The driver sets the IviSwtch>>Scanning Configuration>>Scan Mode [SCN] property to this value. The scan mode specifies how the instrument breaks existing connections when scanning.

Defined Values

IVISWTCH_VAL_NONE (0) The instrument takes no action on existing connections.

IVISWTCH_VAL_BREAK_BEFORE_MAKE (1) The instrument breaks an existing connection before creating a new one. This is useful if you want to prevent two channels from connecting together in the transitional period.

IVISWTCH_VAL_BREAK_AFTER_MAKE (2) The instrument breaks an existing connection after creating a new one. This is useful if you want to prevent damage from occurring on inductive elements of a circuit that cannot stand rapid changes in the current flow.

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instrument handle out

The instrument handle that you obtain from the IviSwtch Initialize Node. The handle identifies a particular instrument session.

Default: None

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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.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

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


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