Siemens Simatic PC Panel PC 870 - Manual (Page 41)

Release 11/02 Connecting and Switching On the Panel PC 670/870
SIMATIC Panel PC 670/870 Start-Up Instructions 2–19
Note
When using standard USB peripheral devices, note that their electromagnetic
interference immunity is often only sufficient for office environments. For startup
and maintenance purposes, such devices are adequate. However, components
suitable for the industrial environment must be used for the process operation.
The USB peripheral devices (e.g. keyboard, printer) are developed and
marketed by individual vendors. Support for the USB periphery devices is
provided via the respective product supplier. The terms of liability of the
individual vendors or suppliers shall apply.
The following types of USB peripheral devices can be distinguished:
• low power USB components:
max. 100 mA current; e.g. mouse, keyboard,
• high power USB components:
max. 500 mA current; e.g. hard disk, floppy drive etc.
In the case of Panel PC 670/870 with power supply up to model edition C (refer
to rating plate Figure 1–3), the following applies:
• High power USB devices can only be used with the front USB port of the
Panel PC 670 if those devices have their own power supply or the devices
are connected via an external USB hub with a separate power supply.
• This restriction is not applicable for operating units with a power supply
from edition model D (refer to rating plate).