List of abbreviations
SIMATIC IPC477E
176
Operating Instructions, 11/2020, A5E37455003-AF
Abbreviation
Term
Meaning
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 Associa-
tion
Syndicate of manufacturers of electrical compo-
nents 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, 7)
NVRAM
Non Volatile Random Access Memory
Non-volatile data memory. Data memory is re-
tained without external power supply.
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 ex-
press
High-speed serial, differential full-duplex PtP in-
terface with high data rate.
PCMCIA
Personal Computer Memory Card Interna-
tional Association
PI
Protective Earth
Protective conductor
PEG
PCI Express Graphics
PG
Programming device
PIC
Programmable Interrupt Controller
Programmable interrupt controller
PIC-E
Peripheral Component Interconnect Ex-
press
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 switch-
gear 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
SLC
Second Level Cache