Enable Breakpoint Output Enables a position breakpoint on an axis or encoder. Details

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

	Enable Breakpoint indicates whether to enable or disable the breakpoint output. Values are True or False.
	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 or Encoder is the axis or encoder to control. You can load Breakpoint Position on encoders mapped to axes 1 through 6 or directly on encoders 0x21 through 0x24.
	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

This VI enables or disables the breakpoint with configuration set by the Configure Breakpoint VI. For single breakpoints, you must re-enable if you want another breakpoint. Buffered and periodic breakpoints only need to be enabled once. When an enabled breakpoint is reached, a breakpoint event occurs. You can use the Read Breakpoint Status VI to see if a breakpoint has occurred.

You can enable only one breakpoint per encoder or axis at a time. When an enabled breakpoint is reached, the breakpoint is automatically disabled. You must explicitly re-enable the breakpoint to use it again. If you need to disable a previously enabled breakpoint, run this VI with Enable Breakpoint set to False.

Note  Enabled breakpoints are also automatically disabled when you execute a Reset Position or Reset Encoder Position VI on the corresponding axis.

Breakpoints are fully functional on independent encoders that are not mapped to axes. In this case, you enable breakpoints directly on the encoder resource.

Note  If you use modulus breakpoints or enable the same breakpoint repeatedly at low velocity (< 50 counts/sec), you may get a breakpoint output immediately after you re-enable it, because the position may not have changed from the last breakpoint. To avoid this problem, use MAX or the Set u32 VI to change the breakpoint window. The breakpoint window is a buffer around the breakpoint position in which a breakpoint is not enabled while the current position remains inside the buffer.

Note  All breakpoints can be affected by jitter in the motion system. For example, if you have breakpoint positions very close to each other, the jitter in the motion system could cause the position to change enough to reach the breakpoint when a breakpoint is not intended. Increase the value of the breakpoint window using Set u32 to compensate for system jitter.

Note  Enabling a high-speed capture when a breakpoint is enabled may cause the breakpoint to be missed. If you are using a breakpoint on the same axis on which you are performing the high-speed capture, ensure that both the breakpoint and the high-speed capture are configured and enabled before starting the move.