Serial communications devices – Rockwell Automation 999 IMC S Class Compact Motion Controller (Cat. No. 4100-999-122) User Manual
Page 57
 
Installation and Hookup
4-15
Publication 999-122 - January 1997
Serial Communications 
Devices
The IMC-S/23x provides two optically-isolated serial ports called 
Serial Port A and Serial Port B. These ports are accessible through the 
9-pin AT-compatible DB-9 connectors on the front panel. Both front 
panel connectors are pinned out identically, so connection to either port 
is the same. 
Serial port A is used for communicating with the GML development 
system and serial port B is used for a serial operator interface device 
for setup and actual machine operation if DH-485 is not used. When 
DH-485 is used, serial port B on the motion controller is used for 
DH-485 communication and the normal built-in operator interface 
functions of the IMC S Class are unavailable. When DH-485 is used, 
do not make any connections to serial port B on the motion controller.
Serial Communication Protocol
When configured for RS-232 or RS-422, both serial ports communicate 
using the standard ASCII character codes at a user selectable baud rate. 
As shipped from the factory, both serial ports are configured for a baud 
rate of 9600. Configure serial communications devices for the serial 
protocol defined below for proper operation with the IMC-S/23x:
!
ATTENTION: Do not connect anything to Serial 
Port B if you are using DH-485.
IMC-S/23x Default Serial Communication Protocol
Parameter
Value
Baud Rate
Start Bits
Stop Bits
Word Length
Parity
XON/XOFF
9600 (others may also be specified)
1
1
8 (7 Data Bits plus Parity)
Ignored
(May be Even, Odd, Mark, or Space) 
ON