Technical data

340 • Glossary

WAGO-I/O-SYSTEM 750

BACnet/IP Controller

Gateway

Device for connecting two different networks, performs the translation be-

tween differing protocols.

Hardware

Electronic, electric and mechanical components of a module.

Header

A portion of the data packet, containing information such as the receiver's

address information.

Host

Originally used to describe a central mainframe computer accessed from

other systems. The services provided by the subscriber can be called up by

means of local and remote request. Today, host can also refer to computers

that provide certain services from a central location (such as UNIX hosts on

the Internet).

HTML (Hypertext Markup Language)

HTML is the descriptive language for documents on the World Wide Web. It

contains language elements for the design of hypertext documents.

HTTP (Hyper Text Transfer Protocol)

Client/Server TCP/IP protocol, which is used on the Internet or Intranets for

exchange of HTML documents. It normally uses Port 80.

Hub

A device, which allows communication between several network users via

Twisted pair cable. Its topology is star-shaped.

HVAC (Heating, Ventilation and Air Conditioning)

HVAC is a special sector of building automation services.