minor differences in the BAS standard: (1) a “horizontal connection point,” which
is similar to telecommunications “consolidation points” or zone cabling, and
(2) a “coverage area” as opposed to telecommunications “work area” (Fig. 2.3).
Despite minor differences, these two standards allow for a single structured
cabling system for a building. Until the recent standard on BAS cabling was
developed, building automation systems were cabled separately using different
cable types and cable pathways.
In addition, these systems have traditionally used hardwired connections of
cables from the BAS equipment to the devices unlike the ubiquitous twisted-
pair RJ-45 connections of the telecommunications network world. This is cur-
rently evolving to increased use of standard cable infrastructure based on
unshielded twisted-pair copper and fiber optic cables.
It should be noted that twisted-pair copper and fiber optic cables are used
extensively in these networks but not all end devices warrant the use of such
cables. For example, twisted-pair cables may be used to connect a PC to a
network but would not be used to connect a mouse or keyboard to the PC.
Similar situations exist with other end devices in other smart building systems.
Twisted-Pair Copper Cable
The core of a twisted-pair copper cable (Fig. 2.4) is made up of two insulated
copper cables twisted together into a “pair.” Four pairs are jacketed together
BAS Channel
Maximum Horizontal
Distance = 90 m
Horizontal Cable
BAS
Outlet
Horizontal
Connection
BAS BAS Patch Panel Point
Controller/
Outstation
BAS
Device
BAS
Device
Horizontal Cable
90 m max
Figure 2.3 Cabling configurations for BAS using structured cable.
The Foundations of a Smart Building 13