Planning for modbus master, Physical connections for modbus rtu -10 – Rockwell Automation AADvance Controller Configuration Guide User Manual
Page 196

9-10
Document: 553633
ICSTT-RM405f-EN-P
Issue 07
Configuration Guide (AADvance Controller)
Maximum number of messages
400
Planning for Modbus Master
You have to complete three activities to use the AADvance controller as a Modbus
master:
Make the physical connections from the controller to the slave devices.
Configure the characteristics of the serial ports (Modbus RTU only).
Set up the project for Modbus master, and configure the application.
There are no interdependencies between these activities, and you can do them in any
order, but you have to complete all three.
Physical Connections for Modbus RTU
Modbus master RTU communications use the serial ports on the 9100 processor base
unit. There are two fundamental topologies possible:
Point to point
Point to multipoint (multi-drop)
Each of these topologies can use a full-duplex, 4-wire (plus signal ground) connection
or a half-duplex, 2-wire (plus signal ground) connection.