Modbus communication protocol, Ascii, Modbus communication protocol ascii – Rockwell Automation 1763 MicroLogix 1100 Programmable Controllers User Manual User Manual
Page 214
Publication 1763-UM001D-EN-P - March 2011
212 Connecting to Networks via RS-232/RS-485 Interface
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 1100 controllers support Modbus RTU Master and Modbus RTU
Slave protocol.
For more information on configuring your MicroLogix 1100 controller for
Modbus protocol, refer to the MicroLogix 1100 Programmable Controllers
Instruction Set Reference Manual, publication 1763-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 for ASCII
driver. Refer to the MicroLogix 1100 Programmable Controllers Instruction
Set Reference Manual, publication 1763-RM001 for detailed configuration
information.
A-B
PanelView
TERM
A
B
COM
SHLD
CHS GND
TX
TX
PWR
TX
DC SOURCE
CABLE
EXTERNAL
PanelView 550
MicroLogix 1100
1761-CBL-AM00
or 1761-CBL-HM02
1747-CP3 or 1761-CBL-AC00
RJ45 port
1761-CBL-AS09
or 1761-CBL-AS03
AIC+
TIP
This 3-node network is not expandable.