Table of Contents
Advertisement
Packet writing
The CD-RW is used as a disk medium. The CD can then be read only by packet–writing
compatible software or has to be finalized. Finalization of a CD closes the CD within an
ISO9660 shell. You can still write to the CD-RW several times in spite of finalization. Not all
CD drives can read packet-written CDs . There are restrictions to using this method in
general data transfer.
PATA
Interface for hard disk drives and optical drives, with parallel data transmission rate up to 100
Mbps.
PC card
Trademark of the Personal Computer Memory Card International Association (PCMCIA).
Designation for auxiliary cards that conform with PCMCIA specifications. A PC card that has
roughly the size of a credit card can be plugged into a PCMCIA slot. Version 1 specifies
cards of Type I with a thickness of 3.3 millimeters, which are designed mainly for use as
external memory. Version 2 of the PCMCIA specification also defines cards of Type II with a
thickness of 5 mm and cards of Type III with a thickness of 10.5 mm. Type II cards can
realize devices such as modems, fax cards and network interface cards. Type III cards are
equipped with devices that require more space, for example wireless communication
modules, or rotary storage media such as hard disk drives, for example.
PC/104 / PC/104-Plus
Two bus architectures are especially fashionable today in the industrial world. PC/104 and
PC/104-
and logical layout of the two bus systems is identical with ISA (PC/104) and PCI (PC/104-
Plus
). Software cannot usually detect a difference between them and normal desktop bus
systems. Their advantage is the compact design and the resulting space they save.
PCMCIA
Association consisting of approx. 450 member companies of the computer industry whose
focus is set on providing worldwide standards for miniaturization and flexible use of PC
expansion cards in order to provide basic technologies to the market.
Pixel
PixElement (picture point). The pixel represents the smallest element that can be reproduced
on-screen or on a printer.
Plug&Play
Generally, a reference to the ability of a computer to automatically configure the system for
communication with peripheral devices (for example monitors, modems or printers). The
user can plug in a peripheral and "play" it at once without manually configuring the system. A
Plug&Play PC requires both a BIOS that supports Plug&Play and a Plug&Play expansion
card.
SIMATIC Rack PC 547B
Operating Instructions, 12/2007, A5E01127519-02
Plus
. Both are standard in single-board computers of the PC class. The electrical
Glossary
129
Advertisement
Table of Contents
