Overview
1.8 Terms for fail-safe operation
Mobile Panels 2nd Generation
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Operating Instructions, 09/2018, A5E33876626-AC
Safety-related operator controls
A fail-safe Mobile Panel comes equipped with the two safety-related operator controls
"Emergency stop / stop button" and "Acknowledgment button". All other operator controls are
not safety-related operator controls.
Fail-safe operation
In a hardwired or PROFIsafe-based F-system, you operate the plant or a plant section in fail-
safe mode. In fail-safe mode, the safety-related operator controls emergency stop/stop
button and enabling buttons are active.
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For a hardwired F-system: Fail-safe mode runs via a fixed connection with a safety relay.
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In a PROFIsafe-based F-system: The HMI device in fail-safe mode detects the signals of
the "emergency stop / stop button" and "enabling button" safety-related operator controls;
communication with the F-system is performed via PROFIsafe.
When configuring the safety functions with the STEP 7 Safety Advanced optional
package, fail-safe operation according to SIL 3 or Performance Level e and Category 4 is
possible with an HMI device of the type KTPx00F Mobile.
The safety-related operator controls can be configured as fail-safe inputs in the safety
program.
Emergency stop, stop
The operator presses the emergency stop / stop button to activate either an emergency stop
or a stop.
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The emergency stop is an emergency action that is intended to stop a process or
movement entailing danger. All machines that are assigned to the trigger are immediately
brought to a safe state via the emergency stop.
●
The emergency stop / stop button of the HMI device brings about a safety-related stop of
the plant or machine in accordance with EN 60204-1, Section 9.2.5.3.
Whether the emergency stop / stop button causes an "emergency stop" or "stop" function
must be decided upon and configured on the basis of the risk assessment.
