List of abbreviations
C.1 Abbreviations
SIMATIC Rack PC 847B
214
Operating Instructions, 06/2008, A5E02203168-01
Abbreviation
Term
Meaning
NAMUR
Normenarbeitsgemeinschaft for Mess- und
Regelungstechnik in der chemischen
Industrie (standardization body for
instrumentation and control technology in
the chemicals industry)
NC
Not Connected
Not connected
NCQ
Native Command Queuing
Automatic re-sorting of the file and disk access,
for increased performance
NEMA
National Electrical Manufacturers
Association
Syndicate of manufacturers of electrical
components in the USA
NMI
Non Maskable Interrupt
Interrupt the processor can not reject
NTFS
New Techniques File System
Secure file system for Windows versions (2000,
XP, Vista)
ODD
Optical Disk Drive
OPC
OLE for Process Control
Standardized interface for industrial processes
PATA
Parallel ATA
PC
Personal computer
PCI
Peripheral Component Interconnect
High-speed expansion bus
PCIe
Peripheral Component Interconnect
express
High-speed serial, differential full-duplex PtP
interface with high data rate.
PCMCIA
Personal Computer Memory Card
International Association
PI
Protective Earth
Protective conductor
PEG
PCI Express Graphics
PG
Programming device
PIC
Programmable Interrupt Controller
Programmable interrupt controller
POST
Power On Self Test
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
RAL
Restricted Access Location
Installation of device in operating facilities with
restricted access - for example, a locked
switchgear cabinet
RAM
Random Access Memory
RI
Ring Input
Incoming call
ROM
Read-Only Memory
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
RxD
Receive Data
Data transfer signal
SATA
Serial Advanced Technology Attachment
SCSI
Small Computer System Interface
SDRAM
Synchronous DRAM
SELV
Safety Extra Low Voltage
Safety extra low voltage