Rockwell Automation 1786-series ControlNet Coax Media Planning and Installation Guide User Manual

Page 32

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32

Publication CNET-IN002B-EN-P - June 2010

Chapter 2 Plan a ControlNet Coax Media System

Redundant Media Example

Each node on a redundant-cable link must support redundant coax
connections and be connected to both trunk cables at all times. Any nodes
connected to only one side of a redundant-cable link will result in media errors
on the unconnected trunk cable.

A node supporting redundant trunk-cable connections will function even if
trunk cable A is connected to the B connector on the node and vice-versa.
This makes cable fault indications (on the hardware or in software) difficult to
interpret and makes locating a bad cable segment very difficult, so be certain to
properly label the trunk and taps with the provided channel A and
channel B labels.

20135-M

1788-RPA

1788-RPCD

CH1

CH2

1788-RPA

1788-RPCD

CH1

CH2

1

2

3

3

3

4

5

5

6

6

6

6

4

1

3

3

3

3

3

1

2

Item

Description

1

Segment (trunk sections and taps between terminating resistors)

2

Trunk cable A

3

Terminating resistor

4

Trunk cable B

5

Repeater

6

Node supporting redundant media

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