Service manual

B-2
Introduction
B
Alarm handling
◆
Introduction
Alarm reporting To monitor long-term stability for changes in the operational parameters (audio sig-
nal loss, network frame loss, AIS etc.), the S
TELLAR
is equipped with an alarm
reporting facility.
There are several reasons for an alarm condition: External events detected by the
S
TELLAR
hardware or, in very rare cases, hardware or software malfunction. To give
network supervisory designers enough flexibility to handle their task, the S
TELLAR
offers several alarm reporting strategies:
• Alarm status reported by relays.
• Alarm status reported by LEDs.
• Alarm status reported by ROSA messages.
Definitions The following terms are used in this section:
Alarm sequences, LEDs
and relays
The BARCO codecs have two alarm LEDs, one button with a LED and 5 relays that
are used to indicate alarms. The LEDs and relays can be used in three different alarm
sequences depending on your needs.
Sequence 1 originates from the British Telecom requirements, and sequence 2 origi-
nates from the Deutsche Telecom requirements. Sequence 3 is a mapping where the
two alarm LEDs and the five alarm relays are used to signal alarm.
For information on how to select the alarm sequence suitable for your needs, see
Which alarm sequence do I select?,p.B-8.
Alarms and ROSA
messages
All events can be assigned both to an alarm relay category and to a message. You can
disable the alarm relay or the message.
Note! Be careful not to assign information messages to alarm relays/LEDs
since once they go active they never go inactive again.
The delay you can set to filter out brief alarm conditions applies both to messages
and relay control.
Term Explanation
Event A change of state in the S
TELLAR
, or a codec response to a user
interaction. A change of state could be that the input has autoswitched
or that there is input loss. The user interaction could be a command
sent to the S
TELLAR
using the command line feature in ROSA. Such
changes are reported to ROSA as messages, and if desired they can be
reported by relays and LEDs as alarms.
Message Every event in the S
TELLAR
is reported by ROSA as a message. All
messages are displayed in the ROSA message list unless disabled.
Alarm Some of the events are of such a severity that you also want an alarm
relay to be pulled, and for the major alarms (A and B) a LED on the
front panel to light.