Siemens PC 677B 用户手册

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页码 32
 
Connecting 
 
4.1 Connection elements and operator controls 
SIMATIC Panel PC 677B 
Operating Instructions (Compact), 06/2008, A5E02217246-01 
19
 
 
NOTICE 
 
On / Off switch 
The On / Off switch does not disconnect the device from the mains. When the switch is in 
the 0 position, the device is still connected to the auxiliary voltage. 
 
Connection components of the control unit 
 
USB connection control unit 
Pos  Name 
Description 
 
 
 
(1) 
USB  
1 connection  
USB 2.0 high current / 
500 mA 
under sealed cover  
(not available with every 
product variant). 
 
 
NOTICE 
 
Ensuring degree of protection P65 
When the sealed cover over the USB interface is removed in order to connect a USB 
component, the IP65 degree of protection for the device is no longer guaranteed. 
 
 
Note 
Use of USB devices 
• 
Wait at least ten seconds between removal and reconnection of USB devices. This also 
applies to control units with touch screen panels, especially for touch operation. 
• 
When using standard USB peripherals, bear in mind that their EMC immunity level is 
frequently designed for office applications only. These devices may be used for 
commissioning and servicing. However, only industry-standard devices are allowed for 
industrial operation. 
• 
Peripherals are developed and marketed by individual vendors. The respective 
manufacturers offer support for the peripherals. Moreover, the terms of liability of the 
individual vendors or suppliers apply here.