Rockwell Automation 1756-DHRIO_DHRIOXT ControlLogix Data Highway Plus-Remote I/O Communication Interface Module - Manual (Page 15)

Rockwell Automation Publication 1756-UM514C-EN-P - June 2014 15
About the Module Chapter 1
Remote I/O
When a channel on the module is configured for Remote I/O, the module acts as
a scanner for the remote I/O network. The ControlLogix controller
communicates to the module’s remote I/O scanner to send and receive the I/O
on the remote I/O network.
The figure shows an example system.
41276
ControlLogix
Chassis
1756-DHRIO ControlLogix Controller
1771-ASB
1746-ASB
PLC-5/20 in Adapter Mode
1794-FLEX I/O
Remote I/O