Rockwell Automation Allen-Bradley ControlNet 1734-ACNR User Manual page 180

C-18 Determine Your ControlNet Media Requirements
Publication CNET-UM001C-EN-P - November 2005
Observe these guidelines when planning a redundant media system in a
hazardous area.
• Route the two trunk cables (trunk cable A and trunk cable B) differently
to reduce the chance of both cables being damaged at the same time.
• 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.
• Install the cable system so that the trunk cables at any physical device
location can be easily identified and labeled with the appropriate icon or
letter. Each redundant ControlNet device is labeled so you can connect
it to the corresponding trunk cable.
• Both trunk cables (trunk cable A and trunk cable B) of a
redundant-cable link must have identical configurations. Each segment
must contain the same number of taps, nodes and repeaters. Connect
nodes and repeaters in the same relative sequence on both trunk cables.
• Each side of a redundant-cable link may contain different lengths of
cable. The total difference in length between the two trunk cables of a
redundant-cable link must not exceed 800m (2640 ft).