Rockwell Automation 1756-DH485 ControlLogix DH-485 Communication Module User Manual - Manual (Page 39)

Publication 1756-UM532A-EN-P - May 2006
Use Data Highway 485 Network 3-7
The message originates on the source network. The destination network is the
message’s target network. This applies to all source and destination networks,
including DH-485, ControlNet, EtherNet/IP, and a ControlLogix chassis
backplane.
Routing Tables in Remote DH-485 Messaging
The 1756-DH485 module contains a routing table that you define for your
application. The routing table contains information used to steer Remote
DH-485 Messages through the system to remote nodes located on separate
networks. By using the routing table, the 1756-DH485 module lets existing
devices, such as an SLC controller, to use DH-485 Remote Addressing for
messaging.
You must use RSLinx software to configure your routing table. Refer to Use
RSLinx Software to Create a Routing Table on page 4-2, for more information.
IMPORTANT
For remote DH-485 messaging, the ControlLogix chassis
backplane should be considered a separate, independent
network. Therefore, a system of 1 DH-485 network and
one ControlLogix chassis is a two-link system.
The ControlLogix chassis backplane is required to be a
separate, independent link for DH-485 messaging if there
is more than one message target ControlLogix controller in
a ControlLogix chassis.