Safety Functions Of The Enabling Button - Siemens Second Wind Function Manual

Storing the HMI device
Non-functional emergency stop button
If the HMI device is not integrated, the emergency stop button does not function.
To avoid confusion between effective and non-effective emergency stop buttons, only one
integrated HMI device should be freely accessible.
If the HMI device is not in use, it must be stored in an secure place.
See also
Emergency stop button (Page 20)
2.8

Safety functions of the enabling button

Introduction
The enabling mechanism is comprised of two enabling buttons mounted on both sides of the
HMI device.
Numerically controlled machines and systems are equipped with the operating modes
"Automatic mode" and "Special mode".
Safety is ensured in automatic mode by means of closed, isolating protective devices and/or
with functional non-isolating protective devices that block access.
In special mode, safety has to be ensured in a different manner than in automatic mode. In
special mode, the danger zones of the machine or system are entered, where controlled
movements have to be possible.
Special mode
A reduced speed on the machine or in the system has to be specified for special mode
based on the risk assessment. Movement of the machine should only be possible when the
enabling device is activated. The operator must have the necessary qualifications and be
acquainted with the details of the intended application.
Safety instructions
The safety-related aspects of the velocity reduction control and those for the enabling device
are designed in such a way that they satisfy the EN 954-1 safety category determined by the
risk analysis.
The operating principles of enabling devices are described in EN 60204. Through the
findings from accident investigations and the existence of technical solutions, the 3-stage
enabling button became state of the art. Positions 1 and 3 of the enabling button are Off
functions. Only the middle position allows the enabling function. EN 60204-1:1997 is
identical to IEC 60204-1, whereby the 3-stage enabling button is gaining international
importance.
Fail-safe operation of the Mobile Panel 277F IWLAN
Function Manual, 08/2008, 6AV6691-1FQ01-2AB0
WARNING
Safety instructions, standards and notes
2.8 Safety functions of the enabling button
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