Force Variable VI

NI Scan Engine VIs

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Force Variable VI

Owning Palette: Forcing VIs

Installed With: RT Module

Forces an I/O variable or I/O alias to assume forced value until you disable forcing, reboot the target, or force the variable to assume a new forced value.

Details  Example

 Place on the block diagram  Find on the Functions palette
variable path (URL) specifies the path to the I/O variable or I/O alias. The path can be absolute or relative. The format of the variable path is \\<TargetName>\<ModuleName>\<VariableName>. You can view the variable path for an I/O variable in the Context Help window when you hover over the I/O variable node on the block diagram.
forced value is the value for the I/O variable or I/O alias to assume while forcing is enabled on the target and the enable forcing input of this VI is TRUE. To ensure data integrity, you must wire a value of the same data type as the I/O variable. To verify the data type of an I/O variable, right-click the I/O variable in the Project Explorer window and select Properties to display the Shared Variable Properties dialog box.
error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use exception control to treat what is normally an error as no error or to treat a warning as an error. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.
status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.
code is the error or warning code. The default is 0. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.
error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error.
status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.
code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.

Force Variable Details

To perform batch forcing on a set of I/O variables, disable forcing on the target, force each I/O variable, then enable forcing on the target.

Example

Refer to the Programmatic Forcing.lvproj in the labview\examples\scanengine directory for an example of using the Force Variable VI.

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