Rockwell Automation 1766-Lxxxx MicroLogix 1400 Programmable Controllers User Manual - Manual (Page 235)

Rockwell Automation Publication 1766-UM001H-EN-P - May 2014 195
Connecting to Networks via RS-232/RS-485 Interface Appendix E
Typical 3-Node Network
Modbus Communication
Protocol Modbus is a Half-Duplex, master-slave communications protocol. The Modbus
network master reads and writes coils and registers. Modbus protocol allows a
single master to communicate with a maximum of 247 slave devices. MicroLogix
1400 controllers support Modbus RTU Master and Modbus RTU Slave
protocol.
For more information on configuring your MicroLogix 1400 controller for
Modbus protocol, refer to the MicroLogix 1400 Programmable Controllers
Instruction Set Reference Manual, publication 1766-RM001. For more
information about the Modbus protocol, see the Modbus Protocol Specifications
(available from
http://www.modbus.org ).
ASCII ASCII provides connection to other ASCII devices, such as bar code readers,
weigh scales, serial printers, and other intelligent devices.
You can use ASCII by configuring the RS-232/485 port, channel 0 and the
RS-232 port, Channel 2 for the ASCII driver. Refer to the MicroLogix 1400
Programmable Controllers Instruction Set Reference Manual, publication
1766-RM001 for detailed configuration information.
Distributed Network
Protocol (DNP3) For more information on configuring your MicroLogix 1400 controller for
Distributed Network Protocol, see Channel Configuration for DNP3 Slave on
page 197. For more information about Distributed Network Protocol, see the
Distributed Network Protocol Specifications, available from
http://www.dnp.org .
TERM A B COM SHLD CHS GND
TX
TX PWR
TX
DC SOURCE
CABLE
EXTERNAL
A-B PanelView
PanelView 550
MicroLogix 1400
1761-CBL-AM00
or 1761-CBL-HM02
1747-CP3 or
1761-CBL-AC00
RJ45 port 1761-CBL-AS09
or 1761-CBL-AS03
CH0
44599
TIP This 3-node network is not expandable.