Rockwell Automation Allen-Bradley ControlNet 1786 Series, Installation Instructions Manual

Page: 35 / 74

Publication CNET-IN002A-EN-P - December 2001
Plan a ControlNet Coax Media System 2-19
•
maximum trunk-cable length of high-flex RG6F trunk cable =
666m (2187ft), with 2 taps
•
75
Ω
terminators are required on both ends
•
one tap with an unconnected drop cable may be installed for
maintenance purposes
•
use BNC bullet connectors at future tap locations
•
do not mix redundant and non-redundant nodes
•
use dummy loads (1786-TCAP) for all other unconnected drop
cables
•
avoid high noise environments when routing cables
Link Planning
•
maximum of 99 nodes (excluding repeaters)
•
repeaters require a tap but are not counted as nodes — they are
included in the number of devices allowed per segment (48)
•
repeaters may be installed at any tap location along a segment
•
there can only be one path between any two points on a link
•
the configuration of both sides of a redundant segment must be
the same
•
The total difference in length between the two trunk cables of a
redundant-cable link goes down as the number of repeaters
increases. See the illustration on page 2-13.