General

The MX-ONE Service Node has a built in alarm log and alarm handling facility. Checking the alarm log should usually be the first step when trying to isolate a fault, malfunction or incorrect configuration.

It is good to make a habit of checking the alarm log often, as the alarm log might indicate service actions that are needed in order to avoid malfunction. The alarm log is distributed. The log is held in the program unit AL (Alarm Log).

There is also a program unit called ALDP (ALarm Device Program). ALDP handles actions configured for alarms and alarm input/output (see chapter Alarm Input/Output).

Every alarm has a code, a domain, and a severity. The combination of a code and a domain identifies the alarm type and gives the alarm name (which is shown when listing alarms). The severity of the alarm can be from 4 (most critical) to 0 (alarm condition was detected, but does not exist any more, or it has been suppressed). The alarms can also have (and usually have) other optional information that assist in finding the cause of the alarm.

Every alarm instance is uniquely identified by its handle. The handle is a number that is automatically assigned to an alarm when it is stored in the alarm log.

A program unit that detects a fault or malfunction and sends an alarm is said to “raise” the alarm. When the alarm condition no longer exists the program unit will “clear” the alarm. A “cleared” alarm will remain in the alarm log, but with a severity of 0. When a system administrator removes an alarm from the log, it is said to “erase” or “reset” the alarm.

With the use of an SNMP agent, alarm information can be propagated to external systems. See the operational directions for MX-ONE SERVICE NODE SNMP SUPPORT AND ALARM NOTIFICATION.