Note: If you wish to override the built-in low and or high alarms for an analog status tag, please refer to Overriding Built-in Alarms.

The Low Alarm Setpoint field enables you to enter the lowest value that this tag's value will be permitted to attain, after which a low alarm will be triggered.  The source for this field may be either a constant, the result of an expression, or the value of a tag.

Please see the topic: Constant, Expression or Tag for more information on selecting between these three choices.

If noise in the system causes a value to fluctuate above and below the setpoint, the alarm will repeatedly switch between active and inactive status.  By using the deadband, you can dampen out these fluctuations by setting an amount by which the tag’s value must rise above the low alarm setpoint before it is considered to no longer be active.  The deadband is used only for changing a current alarm’s active status. It does not affect the setpoint.

Spikes in value below the setpoint may cause transient alarms.  By setting a low alarm delay, you can specify that if the tag’s value rises above the setpoint, it must remain above for a given length of time before the alarm condition is considered to no longer be active 

If required, refer to the topic: Constant, Expression or Tag for more information on selecting between these three choices.

The Low Alarm Priority drop-down list enables you to select the priority of the low alarm that will be triggered for this tag if its value drops below the value defined for the Low Alarm Setpoint. The available priorities are:

•    0 – Event

•    1 – Critical Alarm

•    2 – High Alarm

•    3 – Warning Alarm

•    4 – Notice Alarm

If you have defined your own alarm priority tags, those will also be available for selection.

The Disable Low Alarm field enables you to specify whether the low alarm for this tag is disabled or enabled. Disabling of alarms is typically used in situations where you wish to avoid false alarms. For example, in the event that routine maintenance is being performed on the equipment represented by this tag, or when you are aware that another interruption in communications will occur for a period of time; in such situations, the alarm can be disabled until the maintenance is complete and communications are reestablished.

A value of 0 (or any tag or expression that returns 0) means that the alarm has not been disabled. Any value other than 0 in this field indicates that the alarm has been disabled.

The value accepted by the Disable Low Alarm field can be provided via any of a constant, an expression, or a tag.  Please see the topic: Constant, Expression or Tag for help selecting which to use.

These work in exactly the same way as the low alarm setpoint, low alarm priority and disable low alarm fields, except that they are used to create an alarm that will be triggered when the tag's value goes above a given setpoint.

If the configuration variable AlarmPopupsEnable is set to 1, then setting either the Low Alarm Popup Enable or the High Alarm Popup Enable, will result in a pop-up dialog being displayed whenever the respective alarm is triggered.  It is strongly suggested that this feature be used sparingly.

The Sound field enables you to identify what sound will be played when this alarm is triggered. The Sound field can be set to blank, 0, 1, or to the name of a .WAV sound file to be played.

If the Sound field is set to 0, no sound will be played when this alarm is triggered.

If the Sound field is set to blank or 1, an alarm sound whose properties are configured on the associated alarm priority tag will be played (see Alarm).

If the Sound field identifies the name of a .WAV sound file, it will override any alarm sound configured for the associated alarm priority tag. When specifying a sound file, you must enter its name and extension (e.g. MySound.wav). The specified sound file must be a .WAV file, and must be stored in the application directory. If the specified sound file is not found, the alarm will revert to using tones as specified in the associated alarm priority tag.