Troubleshooting Line Error Active alarms

The following alarm is displayed in Alarm Monitoring: "Line Error Active." When this is displayed, the following troubleshooting steps should be taken.

1) Identify the device reporting the Line Error Active and then repair/replace it.

2) If the device proves itself fully functional, verify that all wires on that cable run are securely connected with no exposed wire and no frayed connections.

3) If multiple devices are running from the same power supply and the supply is close to full load, inrush current may be placing an undue load on the power supply, causing a device to fluctuate on and off line. (Check to see if the problem coincides with a door strike opening.)

4) The resistance ranges defining foreign voltage are set through the EOL, and can be adjusted.

Line Error Active is an introduction of foreign voltage, or resistance, on a monitored line (but it does more). A simple example of this fault would be several isolated lines becoming bared of insulation at the same point and touching each other. A malicious example of this would be someone trying to hide the true status of a point by attempted duplication of the line's actual voltage, or resistance. In addition to the foreign voltage/resistance condition, Line Error Active is also tied to a non settling voltage condition. This condition is reported if the circuit does not settle into a stable state within approximately 200 milliseconds, and can even be reported on a non-supervised circuit. An example of this fault would be an oxidized door contact, and the problem would almost always be on the OPEN to CLOSE transition. Think of this condition as too many bounces on the transition. When a Line Error Active appears on a non-supervised circuit, this is the cause; locate the device (Door Contact, REX switch, Float Switch, etc.) on this line and replace it.

Contact the Lenel Technical Support group for further clarification and assistance.

This article was published in the Volume VI Lenel Technical Support Bulletin.