Allen-Bradley 2080-LC20-20QBB User Manual page 14

Chapter 1 Hardware Overview
4
Embedded RS232/RS485 Serial Port Combo
The Micro820 controller supports an embedded non-isolated RS232/RS485
combo communications port. Only one port (RS232 or RS485) can work at any
given time. The baud rate of this port supports up to 38.4 K.
The communication port uses a 6-pin 3.5 mm terminal block with pin definition
shown in the following table.
IMPORTANT Serial port cables should not exceed 3 m length.
RS232/RS485 Serial Port Pin Definition
Pin
D+ G Tx
1 2 3 4 5 6
D- Rx G
1
2
3
4
5
6
The communication port (both RS232 and RS485) are non-isolated. The signal
ground of the port is not isolated to the logic ground of the controller.
The RS232 port supports connection to the Micro800 Remote LCD module
(2080-REMLCD).
REMLCD to Micro820 Serial Port Terminal Block Wiring
REMLCD Serial Port
Terminal Block
Signal Pin
number
RS232 TX 1 <-------->
RS232 RX 2 <-------->
RS232 G 3 <-------->
Definition
RS485+
RS485-
GND
RS232 input (receiver)
RS232 output (driver)
GND
Micro820 Serial Port
Terminal Block
Pin Signal
number
4 RX RS232
5 TX RS232
6 G RS232
Rockwell Automation Publication 2080-UM005E-EN-E - March 2018
RS485 RS232
Example Example
RS485+ (not used)
RS485- (not used)
GND GND
(not used) RxD
(not used) TxD
GND GND