Cisco Systems Cisco 12008 manual Connecting an External Alarm Monitoring Facility

Connecting an External Alarm Monitoring Facility

The alarm signals sent to this DB-25 connector correspond to those sent to the system alarm LEDs on the CSC faceplate (see Figure 3-16). Thus, a critical, major, or minor alarm condition detected in the router can trigger a simultaneous fault indication in some or all of the following ways:

•System alarm LEDs—The three system alarm LEDs on the CSC faceplate constitute the standard method of alarm notification in the router.

These LEDs indicate router status at all times, but you must directly observe these LEDs to become aware of a router alarm condition. Thus, these LEDs provide only a passive alarm notification capability.

•External alarm monitoring facility—By equipping your router with a telco-style external alarm monitoring facility, you can provide a more overt indication of router status.

For example, the same alarm signal that illuminates one of the three system alarm LEDs on the CSC faceplate for a critical, major, or minor alarm condition is also sent to the DB-25 connector by means of an associated alarm relay in the CSC.

An external alarm monitoring facility uses this signal to activate a visible alarm (such as a flashing light) or an audible alarm (such as a Klaxon) that immediately alerts site personnel to the existence of a router alarm condition.

Installing a Cisco 12008 3-35