Rockwell Automation 5720 DriveLogix System - Manual (Page 216)

Publication 20D-UM002C-EN-P - November 2003
10-6 Communicating with Devices on a DH-485 Link
The maximum node address should be the same for all devices on a DH-485
network for optimal operation.
The best network performance occurs when node addresses start at 0 and are
assigned in sequential order. The controller defaults to node address 1
(controllers cannot be node 0). Initiators, such as personal computers, should
be assigned the lowest numbered addresses to minimize the time required to
initialize the network.
Installing a DH-485
Network A DH-485 network consists of a number of cable segments daisy-chained
together. The total length of the cable segments cannot exceed 1219 m (4000
ft).
When cutting cable segments, make them long enough to route them from one
link coupler to the next with sufficient slack to prevent strain on the
connector. Allow enough extra cable to prevent chafing and kinking in the
cable.
IMPORTANT
Use shielded, twisted-pair cable - either Belden 3106A or Belden 9842. A
daisy-chained network is recommended. Star connections are not recommended