Siemens SIMATIC IPC427C Operations Instructions download pdf (Page 173)

Glossary

SIMATIC IPC427C

Operating Instructions, 10/2010, A5E02414743-03

173

Module

Modules are plug-in units for PLCs, programming devices or PCs. They are available as

local modules, expansion modules, interfaces or mass storage (Mass storage module).

Motherboard

The motherboard is the core of the computer. Here, data are processed and stored, and

interfaces and device I/Os are controlled and managed.

NEC Class 2

The "NEC", National Electrical Code, is the USA collection of regulations that generally

correspond to German VDE 0100 standards. All USA standards governing the safety of

electrical equipment and corresponding "deviations" in IEC standards are based on NEC in

terms of their country-specific requirements.

NEC Class 2 specifies higher safety requirements for protection against electric shock and

National Fire Protection Association (NFPA) requirements for fire protection. Power supplies

operating within the range from 20 VDC to 30 VDC must be equipped with an internal current

limiting circuit which safely prevents output power higher than 100 VA.

Operating system

Generic term which describes all functions for controlling and monitoring user program

execution, distribution of system resources to the user programs and the operating mode in

cooperation with the hardware (for example Windows XP Professional).

Packet writing

The CD-RW is used as a disk medium. The CD can then be read only by packet–writing

compatible software or has to be finalized. Finalization of a CD closes the CD within an

ISO9660 shell. You can still write to the CD-RW several times in spite of finalization. Not all

CD drives can read packet-written CDs . There are restrictions to using this method in

general data transfer.

PATA

Interface for hard disk drives and optical drives, with parallel data transmission rate up to 100

Mbps.

PC card

Trademark of the Personal Computer Memory Card International Association (PCMCIA).

Designation for auxiliary cards that conform with PCMCIA specifications. A PC card that has

roughly the size of a credit card can be plugged into a PCMCIA slot. Version 1 specifies

cards of Type I with a thickness of 3.3 millimeters, which are designed mainly for use as

external memory. Version 2 of the PCMCIA specification also defines cards of Type II with a

thickness of 5 mm and cards of Type III with a thickness of 10.5 mm. Type II cards can

realize devices such as modems, fax cards and network interface cards. Type III cards are

equipped with devices that require more space, for example wireless communications

modules, or rotary storage media such as hard disk drives, for example.

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Siemens SIMATIC IPC427C Operations Instructions Page 173