Siemens 620 Manual De Usuario

Glossary-3

SIMATIC Box PC 620  Manual

A5E00131465-01

Duplicate of a program, storage medium or database. Created to backup or to

protect irreplaceable data of working copies as a precaution against corruption or

destruction. Some applications automatically create backup copies, while

managing both the current version as well as the previous version that is stored on

the hard disk drive.

The base memory is a part of the main memory. It is 640 Kbytes for all
programming devices. The size is entered in the SETUP menu under the entry
“System Memory” and is not changed even if the memory is extended.

In personal computers, batteries are used as an auxiliary source of power when
the main power is shut off, as a power source for laptop and notebook computers
(rechargeable batteries, such as nickel cadmium, nickel metal hydride, and lithium
ion, are used), and as a method to keep the internal clock and the circuitry
responsible for the part of RAM that stores important system information always
powered up.  Strictly speaking, only batteries that are not rechargeable are
classified as batteries.

Acronym for Basic Input/Output System. On PC-compatible computers, the set of

essential software routines that tests hardware at startup, starts the operating

system, and supports the transfer of data among hardware devices.

Boot disk that contains a boot sector and an initial loader for the operating system.

Start or restart of the PG. During the boot sequence the operating system is

transferred from the system drive into the main memory.

Loading operation which transfers the operating system to the main memory.

The speed (in bits per second) with which information is transmitted over a data
link.