LINK LEDs find Cable Problems

SynqNet supports the 100BT industry standard LINK LED to assist in cabling systems. This is the same LINK functionality that is supported by the network card on a desktop workstation. Each 100BT receiver monitors the network for a valid receive signal, and turns ON the LINK LED when a valid signal is detected. Checking for a LINK LED ON at both ends of one cable confirms valid communication across the cable in both directions.

NOTE: The LINK LED does NOT need actual packet traffic to be turned ON. As long as there is a valid link connection, the LINK LED will be turned ON.

The LINK LEDs can also be used to check cables when a system is assembled. There will be two LEDs near each SynqNet connector. One is the LINK LED; the other is either CYCLIC or REPEATER. As each cable is attached, the LINK LEDs at both ends should go ON. When the nodes are undiscovered (for example, after power on), CYCLIC will be BLINKing, and REPEATER will be OFF. Therefore after installing a cable, there will be exactly one LED ON near each connector. If the LINK LED does not go ON, check that the cable connects an IN port to an OUT port. Check that the cable is NOT a crossover pinout. Check that both nodes are powered on.

The LINK LEDs can also be used to find a cable that has failed. First, perform a safe shutdown of the network. Then inspect the LEDs at the connectors. There should be exactly one LED ON near each cable connector (the second LED will be BLINKing or OFF as discussed above).