Overview Of The Safety Functions Integrated In The Drive - Siemens SINUMERIK 840D sl Function Manual

05.08
Acquiring
In order to connect sensors and actuators in a safety–related fashion, their process
signals must be connected–in for further processing.
Analyzing
The two drive CPUs independently execute the safety–related functions. The
CPUs cyclically and mutually compare their safety–related data and results (cross-
wise data comparison). A test can be carried out – initiated by the CPUs – to check
the shutdown paths and actuators (forced checking procedure).
Responding
When the integrated safety–related functions respond, the drive processors can
act on the connected actuators in a safety–related fashion in–line with the actual
situation. For example, the appropriate stop responses for the drives can be initi-
ated and/or the brakes activated.
2.3.1

Overview of the safety functions integrated in the drive

The safety–related functions are available in all of the operating modes and can
communicate with the process via safety–related input/output signals. These can
be implemented individually for each axis.
S Safe Torque Off (STO)
The drive pulses are cancelled and therefore the energy feed is safely and elec-
tronically disconnected
S Safe Brake Control (SBC)
The brake is directly controlled at the Motor Module Ô through two channels
and monitored
S Safe Stop 1 (SS1)
Braking along the OFF3 ramp, monitoring the stopping time and transition into
STO
© Siemens AG 2008 All Rights Reserved
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 05.2008 Edition
2.3 Safety technology integrated in the drive
Brief Description
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