Read Breakpoint Status

NI-Motion VI

Read Breakpoint Status

Reads the breakpoint status for all axes or encoders.

Note Note  You cannot use this VI to read the status of buffered breakpoints. Use Check Buffer to get the status of the buffer.

Details

Device Compatibility

DeviceCompatibility
7330
Y
7340
Y
7344
Y
7350
Y
7390
Y
NI SoftMotion Controller for CANopen—Accelnet
N
NI SoftMotion Controller for CANopen—Xenus
N
Breakpoint Type (Position) is a reserved input that must be set to Position Breakpoint (0).
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 control or encoder control selector. For multi-axis status, use 0 (zero). For multi-encoder status, use 0x20.
Ret Vect indicates the destination for the return data generated by this VI. Available return vectors include return data to the host (0xFF), return data to a variable (0x01 through 0x78), return data to an indirect variable (0x81 through 0xF8), and do not return data (0). Refer to Input and Return Vectors for more detailed information.
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.
Breakpoint Status is the bitmap of breakpoint status for all axes or all encoders.
Note  The breakpoint status does not reflect the voltage level of the breakpoint output.

When reading breakpoint status for axes (Axis or Encoder = 0) or encoders (Axis or Encoder = 0x20):

Axis or Encoder 1—If true, breakpoint occurred. If false, breakpoint pending or disabled.
Axis or Encoder 2—If true, breakpoint occurred. If false, breakpoint pending or disabled.
Axis or Encoder 3—If true, breakpoint occurred. If false, breakpoint pending or disabled.
Axis or Encoder 4—If true, breakpoint occurred. If false, breakpoint pending or disabled.
Axis or Encoder 5—If true, breakpoint occurred. If false, breakpoint pending or disabled.
Axis or Encoder 6—If true, breakpoint occurred. If false, breakpoint pending or disabled.
Axis or Encoder 7—If true, breakpoint occurred. If false, breakpoint pending or disabled.
Axis or Encoder 8—If true, breakpoint occurred. If false, breakpoint pending or disabled.
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 allows you to see if a breakpoint has occurred or is pending. When you enable a breakpoint, the corresponding status bit is reset to indicate that the breakpoint is pending. For single breakpoints, this status is set when a breakpoint occurs. Periodic breakpoints only set the breakpoint status after the first breakpoint has occurred, and the status remains asserted across the subsequent breakpoints. When the breakpoint position is reached, its status bit is set to True (1).

Example

Executing the Read Breakpoint Status VI with Axis or Encoder = 0x20 and Breakpoint Type = 0 returns Breakpoint Status, which corresponds to the following bitmap.

Axis/
Encoder 1   
Axis/
Encoder 2  
Axis/
Encoder 3   
Axis/
Encoder 4   
Axis/
Encoder 5   
Axis/
Encoder 6
Axis/
Encoder 7   
Axis/
Encoder 8   
True  False  False  True  False  False  False  False 

On encoders 1 and 4, breakpoints have occurred, but on encoders 2 and 3, breakpoints are pending or were never enabled.

Note  Read Breakpoints Status returns the breakpoint status for either all axes or all encoders, based on which value is passed into Axis or Encoder.