Overview 
  1.2 Design of the device 
SIMATIC IPC547D 
Operating Instructions, 06/2011, A5E03473780-01 
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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. 
 
 
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 
 
 
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.