Rockwell Automation 1786-series ControlNet Coax Media Planning and Installation Guide - Manual (Page 40)

40 Publication CNET-IN002B-EN-P - June 2010
Chapter 2 Plan a ControlNet Coax Media System
Review the Plan,
Order Components Now that you are ready to order components, use the checklists to make sure
that your system plan follows these guidelines. Refer to the table on
page 41 to
select components.
IMPORTANT
The ControlNet cable is isolated from earth and must be
protected from inadvertent ground connections.
Segment Planning
All connections to the trunk cable require a tap.
Taps can be installed at any location on the trunk cable.
Tap drop-cable length must not be changed. Bend radius is 1.5 in.
Maximum number of taps = 48, with 250 m (820 ft) of standard RG-6 trunk cable.
Maximum number of taps = 48, with 111 m (365.2 ft) of RG6F high-flex trunk cable.
Maximum trunk-cable length of standard RG-6 trunk cable = 1000 m (3280 ft),
with two taps.
Maximum trunk-cable length of high-flex RG6F trunk cable = 443 m (1455 ft),
with two taps.
75
Ω
terminating resistors are required on both ends of each segment.
One tap with an unconnected drop cable may be installed for maintenance purposes.
Use dummy loads (catalog number 1786-TCAP) for all other unconnected drop cables.
Use BNC bullet connectors at future tap locations.
Do not mix redundant and non-redundant nodes.
Avoid high-noise environments when routing cables; see the MICE concept
in IEC 61918.
Link Planning
Maximum is 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.
Only one path can be between any two points on a link.
The configuration of both sides of a redundant segment must be the same.