Read Return Data Buffer

NI-Motion VI

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Read Return Data Buffer

Reads the Return Data Buffer.

Device Compatibility

Device	Compatibility
7330	Y
7340	Y
7344	Y
7350	Y
7390	Y
NI SoftMotion Controller for CANopen—Accelnet	N
NI SoftMotion Controller for CANopen—Xenus	N

Board ID is a unique number assigned by Measurement & Automation Explorer (MAX) used to send and receive commands and data to or from a specific NI motion controller.

error in (no error) describes error conditions that occur before this VI runs. The default input of this cluster is no error. If an error already occurred, this VI returns the value of error in in error out. The VI runs normally only if no incoming error exists. Otherwise, the VI passes the error in value to error out. The error in cluster contains the following parameters:

	status is TRUE if an error occurred before this VI was called, or FALSE if not. If status is TRUE, code is a nonzero error code. If status is FALSE, code is zero or a warning code.
	code is a number identifying an error or warning. If status is TRUE, code is a nonzero error code. If status is FALSE, code is zero or a warning code. Use the error handler VIs to look up the meaning of this code and display the corresponding error message.
	source is a string that indicates the origin of the error, if any. Typically, source is the name of the VI in which the error occurred.

Word Count is the number of 16-bit words in the command packet.

Data Out is the data read from the return data buffer.

Bd ID Out is provided for flow control. You can string together NI-Motion VIs by wiring the Bd ID Out terminal of one VI to the Board ID terminal of the next VI.

error out contains error information. If error in indicates an error, error out contains the same error information. Otherwise, it describes the error status that this VI produces.

	status is TRUE if an error occurred, or FALSE if not. If status is TRUE, code is a nonzero error code. If status is FALSE, code is zero or a warning code.
	code is a number identifying an error or warning. If status is TRUE, code is a nonzero error code. If status is FALSE, code is zero or a warning code. Use the error handler VIs to look up the meaning of this code and display the corresponding error message.
	source is a string that indicates the origin of the error, if any. Typically, source is the name of the VI in which the error occurred.

Resource ID Out is the device number being returned by the controller.

Command ID Out is the command ID being returned by the controller.

Using This VI

You can use the Read Return Data Buffer VI to read the RDB.

Refer to the motion controller documentation for more information about low-level communications protocols and return data packets.

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