You are here: NI Home > Support > Product Reference > Manuals > LabVIEW FPGA Module 8.2 Help

Allows you to call a compiled FPGA VI as a subVI from a host VI. Use the Call VI function to communicate with front panel objects in the FPGA VI. The Call VI function downloads the FPGA VI to the FPGA target unless the FPGA VI already has been downloaded to the target. Some FPGA targets might not support the Call VI function. Refer to the specific FPGA target hardware documentation for information about support of the Call VI function. Details  

	FPGA VI Reference In is the reference to the FPGA VI running on the FPGA target. Right-click the Call VI function and select FPGA VI Reference Input from the shortcut menu to access this parameter. You must open a reference to the FPGA VI to use this parameter.
	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 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.
	FPGA VI Reference Out returns a reference to the FPGA VI running on the FPGA target. Right-click the Call VI function and select FPGA VI Reference Input from the shortcut menu to access this parameter.
	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.

Call VI Details

To specify the FPGA VI to call, right-click the function on the block diagram and select Select VI from the shortcut menu. You also can select a compiled bitfile. Right-click the Call VI function and select Select Bitfile from the shortcut menu. Right-click the Call VI function and select Terminals Visible from the shortcut menu to display the terminals of the FPGA VI instead of the icon.

The Call VI function is similar to the Call By Reference Node. When the Call VI function runs, LabVIEW writes all the inputs to the FPGA VI. The FPGA VI then runs to completion. LabVIEW then returns all outputs from the FPGA VI.

Do not use the Call VI function for an FPGA VI that does not terminate.

You must compile the FPGA VI before the Call VI function can download or run the VI on the FPGA target.