User guide

Glossary - 3

FHSS (Frequency Hopping Spread Spectrum). A method of transmitting radio signals by rapidly switching a carrier

among many frequency channels, using a pseudorandom sequence known to both transmitter and receiver.

Hz. Hertz; A unit of frequency equal to one cycle per second.

Host Computer. A computer that serves other terminals in a network, providing such services as computation,

database access, supervisory programs and network control.

IEC. International Electrotechnical Commission. This international agency regulates laser safety by specifying various

laser operation classes based on power output during operation.

IEC (825) Class 1. This is the lowest power IEC laser classification. Conformity is ensured through a software restriction

of 120 seconds of laser operation within any 1000 second window and an automatic laser shutdown if the scanner's

oscillating mirror fails.

IEEE Address. See MAC Address.

Input/Output Ports. I/O ports are primarily dedicated to passing information into or out of the terminal’s memory. MC40

mobile computers include USB ports.

Internet Protocol Address. See IP.

I/O Ports. The connection between two devices, defined by common physical characteristics, signal characteristics, and

signal meanings. Types of interfaces include RS-232 and USB.

IP. Internet Protocol. The IP part of the TCP/IP communications protocol. IP implements the network layer (layer 3) of

the protocol, which contains a network address and is used to route a message to a different network or subnetwork.

IP accepts “packets” from the layer 4 transport protocol (TCP or UDP), adds its own header to it and delivers a

“datagram” to the layer 2 data link protocol. It may also break the packet into fragments to support the maximum

transmission unit (MTU) of the network.

IP Address. (Internet Protocol address) The address of a computer attached to an IP network. Every client and server

station must have a unique IP address. A 32-bit address used by a computer on a IP network. Client workstations

have either a permanent address or one that is dynamically assigned to them each session. IP addresses are written

as four sets of numbers separated by periods; for example, 204.171.64.2.

IPX/SPX. Internet Package Exchange/Sequential Packet Exchange. A communications protocol for Novell. IPX is

Novell’s Layer 3 protocol, similar to XNS and IP, and used in NetWare networks. SPX is Novell's version of the Xerox

SPP protocol.

ISM. Industry Scientific and Medical