Quick Start Manual
Installation Guide for the Model EN516 Ethernet Hub
4-2 Troubleshooting
• Defective connectors are being used.
For further information on pin assignment and cable specifications, refer to Appendix B, “Cabling 
Specifications,” and Appendix C, “Connector Pin Assignments.”
Link/Rx LED for the RJ-45 Ports
The green Link/Rx LED on each RJ-45 port turns on when a link is established successfully 
between the hub and a PC or other device. It is off when there is no data link and/or the cable is not 
connected. If the Link/Rx LED is not on after cabling has been installed, check for a bad cable, 
cable pairs that are not correctly wired, or loose connectors. Also check to see whether or not there 
is power for both the hub and the Ethernet transceiver on the connected PC or other device.
The green Link/Rx LED indicator blinks when there is data reception on the port.
AUI Rx LED and BNC Rx LED for the AUI and BNC Ports
The green AUI Rx LED and BNC Rx LED blink when there is data reception on the AUI or BNC 
port.
Partition LED for the RJ-45 Ports
The yellow Partition LED on each of the RJ-45 ports turns on when the port is being partitioned 
after 32 continuous collisions are detected on the connected segment. After the first good packet 
without a collision is received, the yellow Partition LED on the RJ-45 port turns off, and the port is 
reconnected.
Partition LED for the BNC Port
The yellow Partition LED indicator turns on when the BNC port has been partitioned after 32 
continuous collisions are detected on the BNC port. After the first good packet without a collision 
is received, the yellow Partition LED on the BNC port turns off, and the port is reconnected.
The BNC port is partitioned when there are one or more of the following conditions:
• No coaxial cable connected to the BNC port
• Faulty cable or connectors
• Excessive collisions on the connected segment










