
FDDI Management
LER Cutoff
The Link Error Rate (LER) Cutoff field displays the threshold at which a connection is flagged as faulty and the port is disabled by Station Management (SMT). SMT automatically
LEM Count
The Link Error Monitor (LEM) Count field displays the number of times each port’s Link Error Monitor detects a link error. A link error occurs when a port’s line state goes from Idle to Unknown and remains there for at least 80 ns, or when the line state goes from Active to Unknown and remains there for at least 320 ns. A growing LEM Count usually indicates a physical problem with the connectors or the cable between a port and the node at the other end of its cable segment. If you can wiggle the cable and watch the LEM Count increase, you know you have a faulty cable or connector. Dirt or film on the connector cable ends can also add to the LEM count.
The lower portion of the window provides the fields you need to configure the alarms:
1.In the Port List Box, select the port or ports for which you would like to edit the alarm thresholds. You can select or
2.In the Alarm Type field, select the alarm variable for which you would like to configure a new threshold: LER Alarm or LER Cutoff.
3.Enter your desired alarm threshold in the Threshold field. The default LER Alarm threshold is 8, and the default LER Cutoff threshold is 7; the allowable range for both is
4.Click on to save your changes. If you wish to configure both LER
Alarm and LER Cutoff thresholds, be sure to click on before switching from one to the other, or the changes you made to the first alarm will be lost.
Alarm Configuration |