Nematron Pointe Controller - Manual (Page 220)

Chapter 8: Networked Operations Pointe Controller User Guide
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8.2 Networking via Modbus Data Mapping
As a control node in a scalable network, the Pointe Controller performs dedicated
real-time local control, while maintaining communications with the designated
supervisory computer. Total system deployment, configuration, project
coordination, and data logging can be implemented from any authorized
network workstation.
The Pointe Controller can be configured to communicate with supervisory
computers and operator terminals via the industry-standard Modbus protocol. To
do this, you must first enable the Modbus driver and then map the
Logic Memory
variables used in PointeControl to the appropriate Modbus addresses. When your
project is downloaded to and run on the Pointe Controller unit, Modbus
communication is started automatically and the unit shares the mapped data over
its serial and/or Ethernet connection.
If you intend to configure Modbus mapping, you should be familiar with the
Modbus protocol and the different
Modbus data types , as defined by Modicon /
Schneider Electric. You should also have a basic understanding of PLC memory
addressing.
NOTE: The Pointe Controller is designed to work as a Modbus slave device,
regardless of whether serial or Ethernet communication is enabled. Anything that
attaches to the Pointe Controller unit via Ethernet is automatically the Modbus
master device and therefore responsible for initiating requests to the controller.