Rockwell Automation 2198-Hxxx Kinetix 5500 Servo Drives User Manual - Manual (Page 169)

Rockwell Automation Publication 2198-UM001D-EN-P - May 2014 169
Kinetix 5500 Safe Torque-off - Integrated Safety Chapter 10
Stop Category Definition
Stop category 0 as defined in EN 60204 or Safe Torque Off as defined by EN
61800-5-2 is achieved with immediate removal of motion producing power to
the actuator.
Performance Level (PL) and Safety Integrity Level (SIL)
For safety-related control systems, Performance Level (PL), according to EN ISO
13849, and SIL levels, according to EN 61508 and EN 62061, include a rating of
the systems ability to perform its safety functions. All of the safety-related
components of the control system must be included in both a risk assessment and
the determination of the achieved levels.
Refer to the EN ISO 13849, EN 61508, and EN 62061 standards for complete
information on requirements for PL and SIL determination.
Description of Operation The safe torque-off (STO) feature provides a method, with sufficiently low
probability of failure, to force the power-transistor control signals to a disabled
state. When the command to allow torque ceases from the GuardLogix
controller, all of the drive output-power transistors are released from the On-
state. This results in a condition where the motor is coasting. Disabling the power
transistor output does not provide mechanical isolation of the electrical output
that is required for some applications.
The 2198-H
xxx-ERS2 drive STO function response time is less than 10 ms.
Response time is the delay between the time the drive STO function receives the
integrated safety packet with an STO request and the time when motion
producing power is removed from the motor.
STO State Reset
The 2198-H
xxx-ERS2 servo drives support only manual restart to exit the STO
state. The transition from logic 0 to 1 of the SO.Reset tag is required after the
SO.SafeTorqueOff tag has transitioned from logic 0 to 1.
IMPORTANT In the event of a malfunction, the most likely stop category is category 0. When
designing the machine application, timing and distance must be considered
for a coast to stop. For more information regarding stop categories, refer to
EN 60204-1.
IMPORTANT Transition of the SO.SafeTorqueOff tag to logic 1 must always be executed
prior to transition of the SO.Reset tag to logic 1.