Appendix
A.3 Glossary Definitions CU
SIMATIC Panel PC 577
Operating Instructions, Release 04/2006, A5E00798484-01
A-9
A.3
A.3
Glossary Definitions CU
Application
An application is a program which is put directly on the operating system MS-DOS or
windows. An application on the PC/PG, for example, is STEP 7.
Programmable controller
The programmable controllers of the SIMATIC S5 system consist of a central unit, one or
several CPUs, and other modules, e.g. input modules and output modules.
Automation system (AS)
A programmable logic controller (PLC), consisting of a central unit, a CPU, and various input
and output modules.
Baud
Unit of measurement for the transmission speed. The unit of measurement, Baud, defines
the number of transferred signal states per second. When only two states occur, one baud is
equivalent to a transmission rate of 1 bps.
Module
Modules are plug-in units for PLCs, programming devices or PCs. Modules exist, for
example, as central modules, power-ons, or as mass storage.
Boot diskette
A boot diskette is a bootstrap loader diskette, which has a boot sector that loads the
operating system from the diskette.
Booting
Start or restart of the computer. During the boot sequence, the operating system is loaded
from the system data carrier into RAM.
Cache
High-speed access buffer often used for interim storage (buffering) of requested data. The
computer has two cache levels, the 2 level.
