Overview Of The Safety Functions Integrated In The System; System Features - Siemens Sinumerik 840D sl Function Manual

Brief description
2.2 Safety technology integrated in the system
Features of the two- -channel, diverse structure
A two--channel, diverse structure is characterized by the following features:
S Two--channel structure with at least 2 independent computers (i.e. computers
with different hardware and software).
S Crosswise result and data comparison with forced checking procedure for the
purpose of detecting internal errors even in functions that are not often used
(dormant errors).
S The computers can access data, reaction--free and decoupled at the shared
(common) interfaces (e.g. actual value input).
Detecting
The actual values of the individual axes are sensed by the sensor modules through
two channels and are provided to the drive and control.
In order to connect sensors and actuators in a safety--related fashion, their process
signals must be connected--in for further processing.
Evaluating
The safety--related functions are executed independently of one another by the
NCK--CPU, PLC--CPU and the drive CPUs. The CPUs cyclically and mutually com-
pare their safety--related data and results (crosswise data comparison). A test can
be carried out -- initiated by the CPUs -- to check the shutdown paths and actuators
(forced checking procedure).
Reacting
When the integrated safety--related functions respond, the drive processors, the
PLC processor and/or the NCK processor can act on the connected actuators in a
safety--related fashion in--line with the actual situation. For example, the appro-
priate stop responses for the drives can be initiated and the actuators shutdown via
the shutdown paths.
2.2.1

Overview of the safety functions integrated in the system

The safety--related functions are available in all of the operating modes and can
communicate with the process via safety--related input/output signals. They can be
implemented for each individual axis and spindle.
S Safe shutdown (stops)
When a monitoring function or a sensor responds (e.g. a light grid), the drives
are safely controlled down to standstill, optimally adapted to the actual opera-
ting state of the machine.
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
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