Security and safety control systems - Intelligent Buildings and Building Automation - page 238

D D D D A A … D D A A

more loops

Control
panel

Panel

D D A A D D … A A D D

Figure 11.10 An addressable fire alarm panel using bus topology at detector level
(D: fire detector, A: actuation device) .

D D A

D A D

Control
panel

more loops

D A D

D A D

Figure 11.11 An addressable fire alarm panel using ring topology at detector level
(D: fire detector, A: actuation device) .

scanning frequency of systems in practice, however, is usually much higher
than this minimum requirement.
Large buildings may need to use a large number of fire alarm panels to be
integrated via a higher-level automation network. A single KNX/EIB system
allows a maximum 225 detector loops at the field level. A single domain of
LonTalk allows a maximum 255 detector loops at the field level. These are
equivalent to a maximum of 7,200 and 8,160 detectors or actuation devices,
respectively, sufficient even for very large building installations.
Traditional addressable fire alarm systems use proprietary protocols. There