Modbus rtu, Modbus/tcp client/server, Cip symbolic client/server – Rockwell Automation 2080-LC50 Micro830 and Micro850 Programmable Controllers User Manual User Manual
Page 56
42
Rockwell Automation Publication 2080-UM002F-EN-E - December 2013
Chapter 5 Communication Connections
Modbus RTU
Modbus is a half-duplex, master-slave communications protocol. The Modbus
network master reads and writes bits and registers. Modbus protocol allows a
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
).
See
Modbus Mapping for Micro800 on page 175
for information on Modbus
mapping. To configure the Serial port as Modbus RTU, see
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 Micro850 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
.
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 Micro830/Micro850 controller.
Micro850 controllers support up to 16 simultaneous EtherNet/IP Client
connections and 16 simultaneous EtherNet/IP Server connections.
CIP Serial, supported on both Micro830 and Micro850 controllers, makes use of
DF1 Full Duplex protocol, which provides point-to-point connection between
two devices.
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.