Reference Manual Owner's manual

Rockwell Automation Publication 750-RM001F-EN-P - February 2012 17
Safety Concept Chapter 1
Stop Category Definitions
The selection of a stop category for each stop function must be determined by a
risk assessment.
• Stop Category 0 is achieved with immediate removal of power to the
actuator, resulting in an uncontrolled coast to stop. Safe Torque Off
accomplishes a Stop Category 0 stop.
• Stop Category 1 is achieved with power available to the machine actuators
to achieve the stop. Power is removed from the actuators when the stop is
achieved.
• Stop Category 2 is a controlled stop with power available to the machine
actuators. The stop is followed by a holding position under power.
Refer to Safe Stop Mode
on page 61 for more information.
IMPORTANT
When designing the machine application, timing and distance should be
considered for a coast to stop (Stop Category 0 or Safe Torque Off). For more
information regarding stop categories, refer to EN 60204-1.