Communications Protocols
Protocols are the set of rules that define a format to communicate data
between network devices and other networks. Protocols may address the rate
or speed of the communications transmission, the mode, the error detection
and the encoding and decoding of data. Protocols can be implemented by
hardware, software, or a combination of the two.
Many years ago data processing was done solely on mainframe computers
or other centralized computers. These systems had proprietary communica-
tions between the user’s “dumb” terminal and the mainframe equipment, both
of which were manufactured by the same company. For example, one could
not take a user’s terminal manufactured by IBM Corporation and use it on
a system made by Digital Equipment Corporation.
Today’s data networks use PCs and devices from multiple manufacturers.
Different PCs can be networked, notonly because they have processing
power and storage that the “dumb” terminals did not have but more impor-
tantly, because they communicate through a common, open communications
protocol. The technology systems in a smart building have adopted and
are migrating to the common network protocols used in data networks
(Fig. 2.8).
Figure 2.8 Ethernet connection.
20 Smart Building Systems for Architects, Owners, and Builders