Siemens Simatic Field PG, Manual

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Glossary
Glossary-13
SIMATIC Field PG Manual
A5E00075760-04
R
RAM (Random Access Memory) is a volatile read/write memory in which every
memory location can be addressed individually and its contents changed. RAM is
used to store data and programs.
Restart
Warm start of a computer in operate state without switching off the power supply
(Ctrl + Alt + Del).
ROM (Read Only Memory) is a non-volatile memory in which every memory
location can be addressed individually. They contain factory set programs and data
that are not lost in the event of a power failure.
The RS-232 interface is a standardized interface for data transmission. Printers,
modems and other hardware modules can be connected to a RS-232 interface.
Real Time Clock
S
Small Computer System Interface. Interface for connecting SCSI devices (hard
disk drives, CD-ROM drives).
Data is transmitted one bit at a time via a serial interface (port); serial interfaces
are therefore slower than parallel interfaces.
Serial Port Adaptors D9/D25
This adapter is used to convert the COM1/V24/PLC interface of the SIMATIC PC
family to a common socket.
RAM
ROM
RS-232 Interface
RTC
SCSI Interface
Serial Interface