Installation Guide Manual

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 23
Get Started with the ControlNet Network Fiber Media System Chapter 1
Install Repeaters in a Combination of Series And Parallel
You can install repeaters in a combination of series and parallel connections. For
mixed topologies (series and parallel) the maximum number of repeaters in series
between any two nodes is 20.
• If you configure your network by using repeaters in combination of series
and parallel, you need to count the repeaters in series on the worst-case
path between any two nodes.
• There can be only one path between any two nodes on a ControlNet
network link. Multiple repeater connections between two segments are
not allowed.
Figure 7 - Repeaters in a Combination of Series and Parallel
In this network example, the maximum number of repeaters that a message will
travel through is 5. The path is as follows: Node 1 to Node 4 travels through
repeaters D, F, C, B, A. Repeaters D and E are in parallel, so you must consider
the path of Node 2 to Node 4 through repeaters E, F, C, B, A. This secondary
path is dependant on the fiber and coax lengths of Segment 1 and Segment 2,
including Segment 7.
31509-M
Coax Segment 7
Repeaters D, E and F are
installed in parallel
Repeater D
Coax Segment 1 Coax Segment 2 Coax Segment 3
Repeater E Repeater F
Node 1 Node 2 Node 3
Repeater A Repeater B Repeater C
Coax Segment 4 Coax Segment 6
Node 4 Node 6
Repeaters A, B, and C are installed in series and connected
to the repeaters in parallel on segment 7 via Repeater F
Node 5
Coax Segment 5
Fiber Cable 1
Fiber Cable 2
Fiber
Cable 3
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See Important on page 16