Siemens SIMATIC HMI IPC677C Operating Instructions Manual page 274

Glossary
Legacy USB support
Support of USB devices (e.g. mouse, keyboard) on the USB ports without driver.
License key
The license key represents the electronic license stamp of a license. Siemens provides the
license keys for protected software.
License key diskette
The license key diskette contains the authorizations or license keys required to enable
protected SIMATIC software.
Low-voltage directive
EC directive for product safety of products operated with low voltage (50 VAC to 1000 VAC,
70V to 1500 VDC) that are not governed by other directives. Compliance is confirmed by the
CE marking and the EC certificate of conformity.
Module
Modules are plug-in units for PLCs, programming devices or PCs. They are available as
central modules, interfaces, expansion modules or mass storage (mass storage modules),
for example.
Module bracket
The module bracket is used to fasten modules and ensure safe contact and transport.
Shocks and vibrations especially affect large, heavy modules. It is therefore recommended
to use the module bracket for this type of module. There are also short, compact and light
modules on the market. The module bracket was not designed for these modules because
the standard fastening is sufficient for them.
Motherboard
The motherboard is the core of the computer. Here, data are processed and stored, and
interfaces and device I/Os are controlled and managed.
PATA
An interface for hard disk drives and optical drives with parallel data transfer of up to 100
Mbps.
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SIMATIC HMI IPC677C
Operating Instructions, 04/2013, A5E02722710-04