Rev. B
2-11
HMXMC001013
31-Mar-06
2.22 ALARM DISPLAY GROUPING
When an alarm state occurs, it is usually prompted to the attention of the system
operators via a flashing text message displayed on one (or more) of the video monitors.
Note:
Usually only particular monitors are used to
display the alarm text messages. To achieve this, ALARM
DISPLAY GROUPING is used.
Every alarm is allocated to one of one hundred (0 99) alarm display groups. During
commissioning, external alarm inputs are allocated to particular alarm display groups.
Note:
Camera fail alarms, PTZ site fail and PTZ site
tamper alarms are always assigned to the default alarm
display group (1).
Now that all possible alarms have been assigned to an alarm display group, the video
output channels (monitors etc.) must be programmed as to which alarm display groups
can display their text messages on which video output channels.
Any combination of alarm display groups (1 99) can be allocated to each video
output channel. Therefore, the one alarm display group could display their text
messages on one monitor, or several monitors simultaneously.
Note:
Alarm display group (0) can NEVER be displayed.
So, any alarm assigned to alarm display group (0) will
never display a text message on any video output
channel. The alarm will still execute its macro sequence.
2.23 THE ALARM STACK
Whenever an alarm becomes active, it is placed onto the alarm stack. If several alarms
become active at the same time, they will all be placed onto the alarm stack in the order
that they occurred.
The purpose of the alarm stack is to cycle between the currently active alarms, re-
displaying their particular text messages and re-executing their particular macro
sequences.
The alarm stack will pause for a pre-defined period between each active alarm recorded
on the stack. The effect is to simulate the various alarm active states over and over
again, similar to the way a video scan sequence would scan several video sources,
allowing time for the operator to observe each alarm.
When the macro sequences for each active alarm have been programmed with
automatic video switching control commands, the alarm stack can create a very
comprehensive and automatic alarm management system within the video system itself.