Rockwell Automation Publication 2080-UM002L-EN-E - November 2021
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Chapter 7 Motion Control
Immediate Hardware Stop
This type of Immediate Stop is controlled by the hardware. If a Hard Stop on a
Hard Limit switch is enabled, and the Hard Limit has been reached, the PTO
pulse for the axis will be cut off immediately by the controller. The stop
response has no delay (less than 1 μs).
Immediate Soft Stop
The maximum possible response delay for this type of stop could be as much as
the Motion Engine Execution time interval. This type of stop is applicable in
the following scenarios:
•
During motion, when axis PTO Pulse Limit is reached;
•
One Hard Limit is enabled for an axis, but Hard Stop on Hard Limit
switch is configured as Off. If the Emergency Stop is configured as
Immediate Software Stop, during motion, when the Hard Limit switch is
detected;
•
One Soft Limit is enabled for an axis and the axis has been homed. If the
emergency stop is configured as Immediate Soft Stop, during motion,
when the Soft Limit reach is detected;
•
The Emergency Stop is configured as Immediate Soft Stop. During
motion, MC_Stop function block is issued with Deceleration parameter
equal to 0.
Decelerating Soft Stop
Decelerating soft stop could be delayed as much as Motion Engine Execution
Time interval. This type of stop is applied in the following scenarios:
•
One Hard Limit is enabled for an axis, but Hard Stop on Hard Limit
switch is configured as Off. If the emergency stop is configured as
decelerating stop, during motion, when the Hard Limit switch is
detected;
•
One Soft Limit is enabled for an axis and the axis has been homed. If the
emergency stop is configured as decelerating stop, during motion, when
the soft limit reach is detected by firmware;
•
The Emergency Stop is configured as Decelerating Stop. During motion,
the MC_Stop function block is issued with deceleration parameter set
to 0.
•
During motion, MC_Stop function block is issued with Deceleration
parameter not set to 0.
