Siemens Simatic 620 - Manual (Page 206)

Glossary
Glossary-16
SIMATIC Box PC 620 Manual
A5E00131465-01
R
RAM
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.
Rechargeable Battery
Reachargeable battery is used as a power source for laptop and notebook
computers independent of external power supply. It also prevents the loss of data
as a result of power failure.
Restart
Warm start of a computer in operate state without switching off the power supply
(Ctrl + Alt + Del).
ROM
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.
RS-232 Interface
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.
RTC
Real Time Clock
S
SCSI Interface
Small Computer System Interface. Interface for connecting SCSI devices (hard
disk drives, CD-ROM drives).
Serial Interface
Data is transmitted one bit at a time via a serial interface (port); serial interfaces
are therefore slower than parallel interfaces.