Master Axis Encoder or ADC is the axis (1 through 15) trajectory generator, encoder (0x21 through 0x2F), or ADC channel (0x51 through 0x5F) to use as the master for this slave axis. A zero (0) value means no master is assigned (default). Note  Axis and Master Axis, Encoder, or ADC cannot be the same because an axis cannot be its own master.
	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.
	Axis is the slave axis to control.
	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.
	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.
	Resource Output is the Axis, Vector Space, ADC, or Encoder you wired into the VI. Use Resource Output to pass the resource to another VI and/or to display information about the device.
	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.

Using This VI

The Configure Gear Master VI assigns a master axis, encoder, or ADC channel to the slave axis selected. Any number of slave axes can have the same master, but each slave axis can have only one master. A slave axis may also serve as master axis for any number of slave axes.

You must call the Configure Gear Master VI prior to enabling master-slave gearing with the Enable Gearing VI. Typically, the source for the master position is an independent encoder, an ADC channel, or the feedback resource of an enabled axis. In each case, you assign the resource, not the axis, as the master. The gear master, which can be an axis, encoder, or ADC, must be enabled before you can use this VI. Use the Enable Axes, Enable Encoders, or Enable ADCs VIs to enable the gear master.

When an axis is assigned as the master, its trajectory generator output (not its feedback position) is used as the master position command. This mode of operation can eliminate the following error skew between the master and slave axes and is especially useful in gantry applications. The master axis can operate in any mode (including as a slave to another master).

Master-slave functionality of slave axes is in addition to their normal mode of operation. This allows a point-to-point move to be superimposed upon the slave while the slave axis is in motion due to being geared to its master. This functionality is useful for registration and reference offset moves. Refer to the Gearing section of the NI-Motion Help for information about using superimposed moves/registration applications. Also, refer to the Rotating Knife section of the NI-Motion Help for example code that includes superimposed moves.

Refer to the Load Gear Ratio and Enable Gearing VIs for more information about master-slave gearing.

Remarks

This section includes information about how the behavior of this VI differs among the controllers that support it.

NI SoftMotion Controller Considerations

The following list includes considerations you must make when you are using this VI with the NI SoftMotion Controller:

• The NI SoftMotion Controller does not support using analog feedback as the gear master (analog gearing).