BECKHOFF C9900-G0xx - Manual (Page 7)

Foreword
C9900-G0xx 5
1.3 Basic safety measures
Before the Industrial PC is switched off, software that is running must be properly closed. Otherwise data
can get lost.
Attention
Switch off system components and disconnect the Control Panel from the
system
Before opening the housing, and whenever the control panel is not being used for
control purposes (such as during functional checks after a repair), all parts of the
equipment must first be switched off, after which the control panel is to be
disconnected from the equipment.
Disconnect the Control Panel by releasing the connectors at the back. System components that have
been switched off must be secured against being switched on again.
Attention
Do not exchange any parts when under power
When components are being fitted or removed, the supply voltage must be switched
off.
Assembly work can cause damage:
 if metal objects such as screws or tools fall onto operating circuit boards.
 if cables are connected or disconnected during operation.