SIMATIC PC Panel PC 677/877, Control Unit
1
Operating Instructions, Edition 04/2005, A5E00407724-01
Glossary
A
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.
Automation device (AD)
The programmable automation devices (AD) 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.
B
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.
Boot diskette
A boot disk is a bootstrap loader diskette, which has a boot sector which loads the operating
system from the diskette.
Booting
The starting or restarting of the computer. During the boot sequence, the operating system is
loaded from the system data carrier into RAM.
C
Cache
High-speed access buffer often used for interim storage (buffering) of requested data. The
computer has two cache levels, the 2 level.
Chipset
Located on the motherboard, interconnects the processor with the RAM, the graphic
controller, the PCI bus, and the external interfaces.
Cold start
A start sequence which begins when the computer is turned on. During a cold start, the
operating system carries out basic hardware checks and then boots.
COM interface
The COM interface is a serial V.24 modem interface. The port is suitable for asynchronous
data transfer. As an alternative, connect printers with a serial interface.
Controller
Installed hardware and software which control the functions of specific internal or external
devices, e.g. the keyboard controller.
