Halytech
hydroSpider2 User’s Manual v1.23
Page 61
5.10.5
Alarm Acknowledgement
Alarms have two basic
activation states
: active and inactive. An alarm is active when its alarm
condition is met, and is inactive when the alarm condition is not met.
In addition to its activation state, alarms also track whether they have been
acknowledged
since
their last activation. Acknowledging an alarm basically indicates that this instance of alarm activation
has been handled and that you now wish to receive alerts for future activations.
Alarms can be acknowledged a number of ways:
Web interface
: the user can access the hydroSpider with a browser, go to the
Alarms
page,
and click on the alarm they wish to acknowledge. See 4.3 - Alarms: Status of Current Alarms.
Auto Acknowledgement
: the hydroSpider can automatically acknowledge the alarm after an
amount of time. Using auto acknowledgement effectively means that an alarm will send out
alerts/reports at most once per auto acknowledgement period.
5.10.6
Alarm Triggering
Triggering refers to the alarm sending out its alerts and reports. Both the activation state and the
acknowledgement state are used to determine whether an alarm will
trigger
and send its
alerts/reports. After an alarm triggers, the alarm will not re-trigger until both of the following have
occurred (in any order):
The alarm has been acknowledged AND
The alarm goes inactive and then active again
This means that an alarm can go active an inactive numerous times, but new alerts/reports will not
be sent until that alarm is acknowledged. This is important because it prevents the alarm from
sending out spurious alerts and reports in the event that its activation state is fluctuating
meaninglessly (eg: the case of a float switch tripping continuously due to tiny changes in water level
around its desired level).
5.10.7
Alarm control activation and deactivation
Alarms can be used to control external systems by assigning them a
control action
such as turning
Switched Power Out
on or off.
The control action is usually performed whenever the alarm enters the active state, regardless of
whether it has been acknowledged, unless the “Once until alarm acknowledged and reactivated”
option has been selected – see the second example below.
As an example, take the scenario where the water level in a tank needs to be maintained at a
particular level. This can be achieved by setting up the hydroSpider to monitor the tank’s water level,
and then setting up two alarms:
Alarm 1: this alarm’s job is to turn on the pump when the water level gets too low.
To achieve this, the alarm is configured to activate when the water level falls below the
tank’s low level, and is assigned a control action (eg: Switched Power Out ON Continuously)
which is wired to trigger the pump to turn on.
Alarm 2: this alarm’s job is to turn off the pump when the water level gets too high.
To achieve this, the alarm is configured to activate when the water level rises above the
tank’s high level, and is assigned a control action (eg: Switched Power OFF Continuously)
which is wired to trigger the pump to turn off.
