Personal Computer User Manual

Abbreviations
C.1 Abbreviations
SIMATIC Rack PC IL 43
Operating Instructions, Edition 09/2005, A5E00432875-01
C-5
Abbreviation Term Definition
PATA Parallel ATA An interface for hard disk drives and optical
drives with parallel data transfer of up to 100
Mbps
PC Personal Computer
PCI Peripheral Component Interconnect High-speed expansion bus
PCMCIA Personal Computer Memory Card
International Association
Association consisting of approx. 450 member
companies of computer industry. Their focus is
set on providing worldwide standards for
miniaturization and flexible use of PC expansion
cards, and thus to provide a basic technology to
the market.
PE Protective Earth
PG Programming device Compact programming device which meets the
special requirements of industry. The PG is fully
equipped for programming SIMATIC PLCs.
PIC Programmable Interrupt Controller Programmable interrupt controller
POST Power On Self Test Self-test performed by the BIOS after the
computer is switched on. Performs a RAM test
and a graphic controller test, for example. The
system outputs audible signals (beep codes) if
the BIOS detects any errors; the relevant
message indicating cause of error is output on
the screen.
PS/2 Personal System 2 PC architecture introduced by IBM towards the
end of the 1980 decade; was originally designed
to replace the open system of the PC AT/XT
format.
PXE Preboot Execution Environment Software for running new PCs without hard disk
data via the network
RAID Redundant Array of Independent Disks Redundant hard disk array. Data storage system
which is used to store data alongside with the
error correction codes (e.g. parity bits) on at least
two hard disks, in order to increase system
reliability and performance. The hard disk array is
controlled by management programs and a hard
disk controller for error correction. The RAID
system is usually implemented in network
servers.
RAM Random Access Memory Main or work memory of a computer with direct
access, allowing read access to data and editing.
RI Ring Input Incoming call
ROM Read-Only Memory Semiconductor memory, can be also used for
storing non-volatile data and programs in the
manufacturing phase. Data stored on the ROM
chip are read-only, and can neither be erased nor
rewritten.
RS 485 Reconciliation Sublayer 485 Bi-directional bus system designed for up to 32
nodes
RTC Real Time Clock Real-time clock
RTS Reliable Transfer Service Request to send