Contemporary Control Systems QuickLink Active Hubs - Manual (Page 4)

FIELD CONNECTIONS
The QL is available with two transceiver options. Each transceiver, which
is matched to a particular cable type, is identified by a three-character suffix
appended to the model numbers. The capabilities of each transceiver
differs. The QL is equipped with either the -CXS or -TPS option, however,
support for systems with either -CXB or -TPB is possible.
-CXS Coaxial Star
In a coaxial star system, NIMs and hubs are interconnected in a point-to-
point fashion using coaxial cable. A NIM can connect to one other NIM or
can connect to a
n unused port on a hub. Hub-to-hub connections are allowed.
In a two-node system, simply connect the two -CXS NIMs together using
RG-62/u coaxial cable. The length of cable cannot exceed 2000 feet.
If more than two NIMs are used on a network, either an active or passive
hub is required. With passive hubs, a maximum of four NIMs can be
interconnected. Unused ports on the passive hub must be terminated with a
93 ohm (nominal) resistor. The maximum length between a passive hub port
and a NIM is 100 feet.
Active hubs provide overall better performance than passive hubs since
greater distances can be achieved along with a degree of isolation. Connect
each NIM to a port on the hub using RG-62/u coaxial cable. This length of
cable cannot exceed 2000 feet nor can the length of cable between two
cascaded hubs exceed 2000 feet. However, up to ten hubs can be cascaded
,
thereby providing an overall cable length of 22,000 feet. Unused ports on
active hubs need not be terminated.
Figure 3 — Point-to-point connections
are required between -CXS NIMs and hubs.
TD990300-0I
H
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