Rockwell Automation 1769-L23E-QB1B_L23E-QBFC1B_L23-QBFC1B CompactLogix Packaged Controllers Quick Start and User Manual - Manual (Page 166)

166 Publication IASIMP-QS010B-EN-P - October 2009
Chapter 2 Network Communication
Serial Communication Each of the CompactLogix packaged controllers has a built-in RS-232 port.
• 1769-L23E-QB1B and 1769-L23E-QBFC1B CompactLogix packaged
controllers have one built-in RS-232 port. By default, that port is
channel 0 on these controllers.
• The 1769-L23-QBFC1B CompactLogix controller has two RS-232
ports that are able to use either DF1 or ASCII protocols.
You can configure the serial port of the controllers for several modes. This
table list the modes available and describes what functionality each mode
offers.
IMPORTANT
Limit the length of serial (RS-232) cables to 15.2 m (50 ft).
CompactLogix Serial Port Configuration
Mode Functions
DF1 Point-to-Point Communication between the controller and one other DF1-protocol-compatible device. This mode is typically used
when downloading and uploading a program to the controller and is the default mode that the serial port operates
in.
Default parameters include:
•
Baud Rate: 19,200
•
Data Bits: 8
•
Parity: None
•
Stop Bits: 1
•
Control Line: No Handshake
•
RTS send Delay: 0
•
RTS Off Delay: 0
DF1 Master Control polling and message transmission between the master and slave nodes.
•
The master/slave network includes one controller configured as the master node and as many as 254 slave
nodes. Link slave nodes by using modems or line drivers.
•
A master/slave network can have node numbers from 0…254. Each node must have a unique node address.
Also, at least two nodes must exist to define your link as a network (one master and one slave station are the
two nodes).
DF1 Slave Use a controller as a slave station in a master/slave serial communication network.
•
When there are multiple slave stations on the network, link slave stations by using modems or line drivers to
the master. When you have a single slave station on the network, you do not need a modem to connect the
slave station to the master. You can configure the control parameters for no handshaking. You can connect
2…255 nodes to a single link. In DF1 Slave mode, a controller uses DF1 half-duplex protocol.
•
One node is designated as the master and it controls which node has access to the link. All the other nodes are
slave stations and must wait for permission from the master before transmitting.
DF1 Radio Modem Compatible with SLC 500 and MicroLogix 1500 controllers, this mode supports:
•
Master and Slave modes.
•
Store and Forward mode.