Read High-Speed Capture StatusReads the high-speed position capture status for all axes or encoders.
| Device Compatibility
|
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:
|
|||||||||||||||||
High-Speed Capture Status
is the bitmap of capture status for all axes or all encoders.
When reading high-speed capture status for axes (Axis or Encoder = 0) or encoders (Axis or Encoder = 0x20), the axis status value are as follows:
|
|||||||||||||||||
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.
|
Using This VI
The Read High-Speed Capture Status VI allows you to see if a position capture has occurred or is pending. When configured as a single high-speed capture, the corresponding status bit is set when an input trigger becomes active, as configured in Configure High-Speed Capture. The status bit, along with the captured encoder position, is latched until the input trigger is re-enabled. When the position capture occurs, its status bit is set to True (1). Refer to the Read Captured Position VI for information about retrieving the captured position value.
Example
Executing the Read High-Speed Capture Status VI with Axis or Encoder = 0 returns High Speed Capture Status, as shown in the following table.
Axis 1 | Axis 2 | Axis 3 | Axis 4 | Axis 5 | Axis 6 | Axis 7 | Axis 8 |
False | True | True | False | False | False | False | False |
On encoders mapped to axes 2 and 3, high-speed captures have occurred, but all other captures are pending or were never enabled.
Remarks
This section includes information about how the behavior of this VI differs among the controllers that support it.
NI 73xx Controller Considerations
The following list includes considerations you must make when you are using this VI with a 73xx motion controller:
- The high-speed capture circuitry is also used during Find Index execution. When an index is found successfully, the capture status for the corresponding encoder and axis is set to True as a side effect.
- Executing the Find Reference Index VI automatically leaves the corresponding high-speed capture input disabled after the index is found.