ADC EMU-830 Manuel D’Utilisation

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The EMU-830 constantly monitors each of the DSL cards for alarm conditions. When so configured, the EMU-830 
provides autonomous dial-out reporting of alarms to remote management stations and printers (see 

). The EMU-830 List 6A monitors the external 2 MHz clock supplied to the 

The alarm status is reported in several ways: alarm LEDs, alarm relays, terminal screens, SNMP traps, and dial-out 
reporting. DSL card alarms can be specified as major, minor, or disabled. Shelf alarms can be specified as major, 
minor, critical, or disabled. A major alarm is asserted when an alarm condition occurs in a card or shelf that is 
specified as major. A minor alarm is asserted when an alarm condition occurs in an DSL card or shelf that is 
specified as minor. Only shelf alarms can be classified as critical. A critical alarm is asserted when any shelf alarm 
occurs that is specified as critical. Use the TAO Main menu to login to an DSL circuit to configure the DSL card 
alarms (see

).

Six alarm relays are provided for use with external alarm indicators such as lights or buzzers. Each relay is a form C 
type which provides three contacts: Common, Normally Open, and Normally Closed. An alarm relay diagram is 
shown in 

The six alarm relays are:

1.

Critical Visual

2.

Critical Audible

3.

Major Visual

4.

Major Audible

5.

Minor Visual

6.

Minor Audible

Additionally, a System ID relay is activated when any minor, major, or critical alarm is active in the shelf. 

The Critical Visual and Critical Audible alarm relays and the System ID relay operate in the fail-safe mode. That is, 
when power is lost to the EMU-830, the Common contact connects to the Normally Open contact.

The ACO (Alarm Cut-Off) function is used to retire active alarms by resetting the minor, major, and critical alarm 
relays (both visual and audible). The Shelf Alarms menu (

) can be used to program which alarm relays 

will and will not be retired when ACO is engaged. ACO can be activated by pressing the front panel ACO switch or 
by connecting the external ACO input (pin 25 of the Alarm connector on a shelf) to ground. ACO is deactivated when 
there are no alarms or when a new alarm occurs.

When connected through a modem to a dedicated telephone line, the EMU-830 can dial-out to a remote 
management station or printer to autonomously report DSL card and shelf alarms. For the EMU-830 to perform this 
function, you must first configure the EMU Modem Parameters, set the severity of the Shelf Alarms, and enable the 
Remote Alarm Reporting option (see 

 through 

Normally Closed

Normally Open

Common