Read/Write Control

Reads a value from or writes a value to a control or indicator in the VI running on the NI-IMAQ I/O device. Details  

	FPGA VI Reference In is the reference to the VI running on the NI-IMAQ I/O device.
	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 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. The default is an empty string.
	FPGA VI Reference Out returns a reference to the VI running on the NI-IMAQ I/O device.
	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 indicator on the front panel 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.

Read/Write Control Details

You can use the Read/Write Control to read whole clusters or an individual element of a cluster. If you need to read multiple elements of a cluster, read the whole cluster. You can write to a whole cluster, but you cannot write to individual elements of a cluster. When you run the host VI, the Read/Write Control reads and writes controls and indicators in the order they appear in the Read/Write Control on the block diagram.

Refer to NI-IMAQ I/O Controls for a list of parameters you can set with this control.