Rockwell Automation 2080-LC20-20QBBR Micro820 20-point Programmable Controllers User Manual - Manual (Page 46)

38 Rockwell Automation Publication 2080-UM005A-EN-E - December 2013
Chapter 5 Communication Connections
single master to communicate with a maximum of 247 slave devices. Micro800
controllers support Modbus RTU Master and Modbus RTU Slave protocol. For
more information on configuring your Micro800 controller for Modbus
protocol, refer to the Connected Components Workbench Online Help. For
more information about the Modbus protocol, refer to the Modbus Protocol
Specifications (available from
http://www.modbus.org ).
See Modbus Mapping for Micro800 on page 249 for information on Modbus
mapping. To configure the Serial port as Modbus RTU, see Configure Modbus
RTU on page 45 .
Modbus/TCP Client/Server
The Modbus/TCP Client/Server communication protocol uses the same
Modbus mapping features as Modbus RTU, but instead of the Serial port, it is
supported over Ethernet. Modbus/TCP Server takes on Modbus Slave features
on Ethernet.
The Micro820 controller supports up to 16 simultaneous Modbus TCP Client
connections and 16 simultaneous Modbus TCP Server connections.
No protocol configuration is required other than configuring the Modbus
mapping table. For information on Modbus mapping, see
Modbus Mapping for
Micro800 on page 249 .
CIP Symbolic Client/Server
CIP Symbolic is supported by any CIP compliant interface including Ethernet
(EtherNet/IP) and Serial Port (CIP Serial). This protocol allows HMIs to easily
connect to the Micro820 controller.
CIP Serial, supported on the Micro820 controller, makes use of DF1 Full Duplex
protocol, which provides point-to-point connection between two devices.
The Micro800 controllers support the protocol through RS232 connection to
external devices, such as computers running RSLinx Classic software, PanelView
Component terminals (firmware revisions 1.70 and above), or other controllers
that support CIP Serial over DF1 Full-Duplex, such as ControlLogix and
CompactLogix controllers that have embedded serial ports.
TIP
Use MSG_MODBUS instruction to send Modbus messages over
serial port.
TIP
Use MSG_MODBUS2 instruction to send Modbus TCP message over
Ethernet port.