Rockwell Automation 1756-DHRIO_DHRIOXT ControlLogix Data Highway Plus-Remote I/O Communication Interface Module - Manual (Page 71)

Rockwell Automation Publication 1756-UM514C-EN-P - June 2014 71
Messaging Between PLC-5 and SLC 5/04 Controllers Chapter 5
Configure the Module Switches
In this application, Channel B on the 1756-DHRIO and 1756-DHRIOXT
modules must be set for DH+.
Configure a Routing Table for the 1756-DHRIO Modules
Use RSLinx to configure a routing table for the 1756-DHRIO and
1756-DHRIOXT modules. The following figure shows the routing table for this
example.
TIP Because the 1756-DHRIO and 1756-DHRIOXT modules are in the same
chassis, you must configure only one of the two routing tables and apply it
to the modules.