58 Rockwell Automation Publication 1766-UM001O-EN-P - September 2021
Chapter 4          Communication Connections
Default Communication 
Configuration
The MicroLogix 1400 communication Channel 0 has the following default 
communication configuration. 
See Chapter 5
 for more information on using the LCD Display.
See Appendix E
 for more information on communicating.
Use the Communications 
Toggle Functionality
The Communications Toggle Functionality can be operated using the LCD 
display on the controller, as shown in Figure 45.
Use the Communications Toggle Functionality to change from the user-
defined communication configuration to the default communications mode 
and back on Channel 0. The Default Communications (DCOMM) indicator on 
the LCD display operates to show when the controller is in the default 
communications mode. Hold down the OK key more than 5 seconds to toggle 
the communication mode on the Main Menu screen.
Figure 45 - Main Menu Screen
For Channel 0, the default configuration is present when:
• The controller is powered-up for the first time.
• The communications toggle functionality specifies default communications (specified 
using the LCD Display. The DCOMM indicator on the LCD Display is on, that is, lit in solid 
rectangle).
• An OS upgrade is completed.
Table 6 - DF1 Full-Duplex Default Configuration Parameters
Parameter Default
Baud Rate 19.2 Kbps
Parity None
Source ID (Node Address) 1
Control Line No handshaking
Error Detection CRC
Embedded Responses Auto detect
Duplicate Packet (Message) Detect Enabled
ACK Timeout counts 50
NAK retries 3
ENQ retries 3
Stop Bits 1
Data Bits 8
The Communication Toggle Functionality only affects the communication configuration 
of Channel 0.
C
OM
M
0
C
OM
M
 1
DCO
MM
B
AT.
 
L
O
U
-
DI
SP
C
OM
M
 
2