Multi-Tech ISIHI-2S Especificaciones descargar pdf (Pagina 178)

178 MultiModemISI Hybrid Series, ISIHI-2S/2U

Glossary

a square envelope or cartridge. A disk drive holds the

floppy disk through the hole in its center and spins it within

its envelope. It can be used over and over again. Contrast

with hard disk.

flow controlThe process of regulating the speed at which

data enters or leaves a serial port. Software flow control is

implemented by communications software or by the user

sending predefined characters or packets which are

recognized as pause and resume indicators. Hardware flow

control is achieved by using the RTS (request to send) and

the CTS (clear to send) control lines of the RS-232 inter-

face.

footprintThe desk or floor space that a piece of hardware

occupies. Also referred to as real estate.

foregroundThe application program currently running on,

and in control of, the PC screen and keyboard. The area of

the screen that occupies the active window. Compare with

background.

format1. The way text is set up on a page. 2. To prepare a

disk for holding information. Formatting a disk can delete

all information on it. 3. The way information is structured

in a file, often specific to one application or protocol.

frequencyA characteristic of an electrical or electronic

signal which describes the periodic recurrence of cycles.

Frequency is inversely proportional to the wavelength or

pulse width of the signal.

FSK (frequency shift keying)A technology that establishes

two frequencies used to represent binary values. This was

the earliest type of modulation used by 300bps modems.

full-duplexMethod of transmitting and receiving data

simultaneously over a single pair of wires. Compare with

half-duplex.

gatewayA workstation that serves as a protocol converter

(translator) between two or more dissimilar networks,

providing incompatible systems.

half-duplexTransmission of data in both directions, but

only one direction at a time. Compare with full-duplex.

handshakingA process that two modems go through at the

time of call setup to establish synchronization over the data

communications link. It is a synchronization and negotia-

tion process, accomplished by the exchange of predefined,

mutually recognized control codes.

hard diskA metal disk covered with magnetic recording

material. Some can hold up to several gigabytes of informa-

tion. Contrast with floppy disk.

hardwareThe equipment that makes up your computer

system, including the keyboard, mouse, disk drives, and

monitor.

hexadecimalA base 16 numbering system used to represent

binary values. Hex uses the numbers 09 and the letters A

f; usually notated by an h (as in 4CF h, read as four charley

fox, hex). The result is that one hex digit represents a four-

bit value.

hostThe computer that is designated as retaining informa-

tion or processing power to service the needs of other

computers or terminal. Mainframes and mid-range comput-

ers are hosts, as well as PCs with powerful microproces-

sors. Often a PC on a LAN will be set up as a host to

provide LAN access for remote users.

I/O addressesLocations within the I/O address space of

your computer used by a device, such as an expansion card,

a serial port, or an internal modem. The address is used for

communication between software and a device.

initializeTo begin anew and establish start-up parameters.

This typically involves clearing all or some part of the

devices memory or disk space.

interfaceA common meeting ground supplied by hardware

or software to facilitate a compatible connection and

operation between two devices or programs. For example,

when two PCs are connected they use a common interface

across the physical connectors so that the signals being sent

and received are accurately interpreted. With software, an

interface is a module created to be written to. That is, if two

programs are written to the same interface, they can be

successfully linked together.

IPX (Internet Packet Exchange)A data transport protocol

developed by Novell used to route messages from one node

to another. Application programs that manage their own

client/server or peer-to-peer communications in a Novell

network can access IPX directly. IPX does not guarantee

the delivery of a message. Compare with SPX.

IRQ level (interrupt request level)The notification a

processor receives when another portion of the computers

hardware requires its attention. IRQs are numbered so that

the device issuing the IRQ can be identified, and so IRQs

can be prioritized.

ISA (Industry Standards Architecture, pronounced ice a)

The classic 8- or 16-bit architecture introduced with IBMs

PC-AT computer. Due to speed constraints, IBM introduced

a restructured Micro Channel Architecture with a 32-bit bus

and increased addressing capabilities.

ISDN (Integrated Services Digital Network)International

telecommunications standard for transmitting voice, video,

and data over a digital communications line.

ISI (intelligent serial interface)Multi-Techs multiport

serial card with an on-board processor and 50K or RAM

for data buffering. The ISI does more than provide addi-

tional serial ports; it enhances serial port performance with

the data buffering, and it holds the data it receives until an

entire block can be transferred to the processor. This allows

the computers processor to be interrupted less often, so it

can perform more efficiently.

jobThe unit of work being processed by the computer.

1 2 ... 173 174 175 176 177 178 179 180 181 182 183 ... 187 188

Comentarios a estos manuales

Sin comentarios

Multi-Tech ISIHI-2S Especificaciones Pagina 178

Comentarios a estos manuales

Relacionado con productos y manuales para Redes Multi-Tech ISIHI-2S