Rockwell Automation 1797-Series ControlNet Ex Media Plannng Installation Manual - Manual (Page 39)

Publication CNET-IN003A-EN-P - January 2006
Plan a ControlNet Ex Media System 2-17
Order Components Now that you are ready to begin ordering components, use these
guidelines to help you select components.
General Planning
The ControlNet Ex cable system is isolated from earth and must be
protected from inadvertent ground connections.
Plan a Segment
Refer to this list when you plan a segment.
•
All connections to the trunk cable require a tap
•
Taps may be installed at any location on the trunk cable
•
Tap drop-cable length must not be changed
•
Maximum number of taps = 48, with 250 m (820 ft) of standard
RG-6 trunk cable
•
Maximum trunk cable length of RG-6 trunk cable = 1000 m
(3280 ft), with 2 taps
•
75
Ω
trunk 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 ControlNet Ex tap terminators (1797-TCAP) for all other
unconnected drop cables
•
Avoid high noise environments when routing cables
•
A supplied ferrite toroid should be used on the ControlNet Ex
trunk as it enters and leaves control cabinets