22 Rockwell Automation Publication 2080-UM002N-EN-E - November 2022
Chapter 1          Hardware Overview
Embedded Ethernet Support
For Micro850 and Micro870 controllers, a 10/100 Base-T Port (with embedded green and yellow 
LED indicators) is available for connection to an Ethernet network through any standard RJ-45 
Ethernet cable. The LED indicators serve as indicators for transmit and receive status.
 
Micro850 and Micro870 controllers support Ethernet crossover cables (2711P-CBL-EX04).
Ethernet Status Indication
Micro850 and Micro870 controllers also support two LEDs for EtherNet/IP™ to indicate the 
following:
• Module status 
•Network status
See Troubleshooting
 on page 307 for descriptions of Module and Network status indicators. 
Yellow LED
Green LED
RJ-45 connector
RJ-45 Ethernet Port Pin Mapping
Contact 
Number
Signal Direction Primary Function
1TX+OUTTransmit data +
2TX-OUTTransmit data -
3RX+IN
Differential Ethernet receive 
data +
4Terminated
5Terminated
6RX-IN
Differential Ethernet receive 
data -
7Terminated
8Terminated
Shield Chassis ground
The yellow status LED indicates 
Link (solid yellow) or No Link (off).
The green status LED indicates 
activity (blinking green) or no 
activity (off).