Combining or switching
s
afety functions
06 A machine can adopt various states or work in various operat‐
ing modes. Within this context, different safety measures may
be effective or different safety functions may be coupled
together. Measures must be implemented to ensure that the
required level of safety is always achieved. The process of
switching between operating modes, or the selection and
adjustment of different safety measures, is not allowed to
lead to a dangerous state.
Initiating a stop 10 A safety-related stop function places the machine in a safe
state on demand (e.g., if a person approaches). To reduce the
required stopping time, it may be advisable to implement a
stop function which complies with stop category 1 (IEC
60204-1-2-9). Additional safety functions may be necessary
to prevent an unexpected restart.
Emergency stop 99 Emergency stop is a supplementary protective measure; it is
no
t a primary means of reducing risk.
The safety level of this function must be defined
based on the risk assessment for the machine. In particular,
influencing environmental factors (e.g., vibrations, method of
actuation, etc.) must be considered.
4.1.3 Implementation of the safety functions
If the Safe Stationary Machine example application is used, the safety functions descri‐
bed be
low must be implemented:
Access protection with standstill monitoring
It is only possible to enter the hazardous area if the Flexi Soft safety controller has
detected that the machine is at a standstill. The safety locking device keeps the safety
door locked while the machine remains in motion.
Safety functions that must be implemented:
•
SF04: Temporarily preventing access
•
SF99 Emergency stop
Setup mode at limited speed
In c
ertain situations (setup, maintenance), the presence of people in the machine's
hazardous area cannot be avoided. In such situations the risk must be reduced by low‐
ering the speed of the machine and making sure that the machine can only move when
an enabling switch is actuated. The actual command that starts the machine must
come from an additional control switch.
The enabling switch must take the form of a three-position switch. Enabling is only
active in position 2. In positions 1 and 3, the drive receives a stop command from the
safety controller and stops the movement.
Following a valid start sequence, the machine speed is monitored by Drive Monitor FX3-
MOC0. If the monitor detects a speed that is higher than the permissible speed, the
safety controller switches off the drive.
Safety functions that must be implemented:
•
SF03: Disabling safety functions manually and for a limited time
•
SF05: Monitoring machine parameters
•
SF99 Emergency stop
Safe stop
A s
afe stop is used to shut down a drive in a controlled manner while monitoring the
stop.
4 P
ROJECT PLANNING
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O P E R A T I N G I N S T R U C T I O N S | Safe Stationary Machine 8020304/2017-07-26 | SICK
Subject to change without notice