Siemens SIMATIC IPC547D Operating Instructions Manual page 17

On/off button
Note
The on/off button is only effective if the power supply is switched on via the on/off switch at
the rear of the device.
NOTICE
On/off button has no function when "Power Failure Recovery" is active
Depending on the BIOS setup, "Power Failure Recovery" entry, the PC switches on
automatically or you must press the on/off button on the front. The BIOS setting only
becomes effective when the device is without mains voltage for at least 20 seconds.
Automatic startup may endanger the operation of the machine or plant, for example, after a
power failure. Take this into account when designing the plant.
The following figure shows the position of the on/off button at the front of the device.
CAUTION
Data loss
The device is restarted in the case of a hardware reset. Data in the main memory is
deleted. Data on the hard disk drive may be lost.
The device is damaged.
Perform a hardware reset only in the case of an emergency. Close all running programs.
Make sure that there is no more read or write access to drives and I/O.
SIMATIC IPC547D
Operating Instructions, 06/2011, A5E03473780-01
1.2 Design of the device
The on/off/reset buttons have three functions:
 Switch on the PC, 1 × press briefly
 Shut down the operating system and
switch off PC, 1 × press briefly
 Switch off PC without shutting down the
operating system, press for more than 4
seconds – hardware reset
Overview
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