Using CitectSCADA > Configuring and Processing Alarms > Time-stamped Analog Alarms > Time-stamped Analog Alarm Properties

Time-stamped Analog Alarm Properties

Time-stamped Analog Alarms have the following properties:

Alarm Tag

The name of the alarm. The name needs to be unique to the cluster. Alarm Tag names need to adhere to the Tag name syntax. If the name is not unique or is not syntactically correct it may not be recognized. If you have many tags, use a naming convention (see Using structured tag names). This makes it easier to find and debug your tags.

Note: Where Cluster Name is left blank, the name needs to be unique to every defined cluster.

Cluster Name

The name of the cluster that runs this alarm. If the Cluster Name is not set, then this alarm will run on every defined cluster.

Alarm Name

The name of the physical device associated with the alarm. This property is optional. It is only used when details of the alarm are displayed on the screen or logged to a device.

Variable Tag

The analog variable (tag) that triggers the alarm.

Setpoint

An analog variable tag or base value that determines if a deviation alarm is to be triggered. This property is optional. If you do not specify a setpoint, it will default to 0 (zero).

High High

The value used as the triggering condition for a high high alarm. The high high alarm becomes active when the value of the variable tag exceeds this value for the duration of the high high delay period. The active alarm has an ON time of when the tag exceeded the high high value.

Because a high alarm needs to precede a high high alarm, when the high high alarm is triggered it replaces the high alarm. If you want an analog alarm to display more than one state on the alarm page at the same time, configure a separate alarm for each state. (Each alarm would monitor the same tag.)

High High Delay

The delay period for High High Alarms. The alarm will only activate if its triggering condition is met for the duration of this period.

This property is optional. If you do not set a value, the high high alarm will be activated as soon as the tag exceeds the high high value.

Note: The delay period needs to be entered in the format HH:MM:SS (hours:minutes:seconds). The value needs to be between 0 seconds (00:00:00) and 24 hours (24:00:00).

High

The value used as the triggering condition for a high alarm. The high alarm becomes active when the value of the variable tag exceeds this value for the duration of the high delay period. The active alarm has an ON time of when the tag exceeded the high value.

High Delay

The delay period for high alarms. The alarm will only activate if its triggering condition is met for the duration of this period.

This property is optional. If you do not set a value, the high alarm will be activated as soon as the tag exceeds the high value.

Note: The delay period needs to be entered in the format HH:MM:SS (hours:minutes:seconds). The value needs to be between 0 seconds (00:00:00) and 24 hours (24:00:00).

When a tag value increases from high to high high within the high delay period, the delay timer is reset. The high high alarm is only activated if the value remains in the high high range for the delay period.

When the value increases from high to high high after the high delay period has expired, a high alarm is activated and then the delay period for the high high alarm begins.

If the tag value exceeds the high high value and then falls below it before the high high delay period expires, at the time it falls, the high alarm is triggered immediately. It has an ON time of when the tag value exceeded the high high value.

These points also apply to tag values travelling between Low and Low Low ranges.

Low

The value used as the triggering condition for a Low Alarm. A Low Alarm becomes active when the value of the Variable Tag drops below this value and remains there for the duration of the Low Delay period. The active alarm has an ON time of when the tag fell below the Low value.

Low Delay

The delay period for Low Alarms. The alarm will only activate if its triggering condition is met for the duration of this period.

This property is optional. If you do not set a value, the Low Alarm is activated as soon as the tag drops below the Low value.

Note: The delay period needs to be entered in the format HH:MM:SS (Hours:Minutes:Seconds). The value needs to be between 0 seconds (00:00:00) and 24 hours (24:00:00).

Low Low

The value used as the triggering condition for a Low Low Alarm. A Low Low Alarm becomes active when the value of the Variable Tag drops below this value and remains there for the duration of the Low Low Delay period. The active alarm has an ON time of when the tag fell below the Low Low value.

Because a Low Alarm needs to precede a Low Low Alarm, when the Low Low Alarm is triggered it replaces the Low Alarm. If you want an analog alarm to display more than one state on the alarm page at the same time, configure a separate alarm for each state. (Each alarm would monitor the same tag.)

Low Low Delay

The delay period for Low Low Alarms. The alarm will only activate if its triggering condition is met for the duration of this period.

This property is optional. If you do not set a value, the Low Low Alarm is activated as soon as the tag drops below the Low Low value.

Note: The delay period needs to be entered in the format HH:MM:SS (Hours:Minutes:Seconds). The value needs to be between 0 seconds (00:00:00) and 24 hours (24:00:00).

Deviation

The value used as the triggering condition for a Deviation Alarm. A Deviation Alarm is activated when the value of the Variable Tag remains outside the deviation range (determined by the Setpoint) for the duration of the Deviation Delay period.

This property is optional. If you do not specify a deviation, no Deviation Alarm is activated.

Deviation Delay

The delay period for Deviation Alarms. The alarm will only activate if its triggering condition is met for the duration of this period.

This property is optional. If you do not set a value, the Deviation Alarm is activated as soon as the Variable Tag falls outside the deviation range.

Note: The delay period needs to be entered in the format HH:MM:SS (Hours:Minutes:Seconds). The value needs to be between 0 seconds (00:00:00) and 24 hours (24:00:00).

Rate

By dividing this value by the alarm period, the "maximum rate" at which the value of the variable tag can change is determined. At each Scan Time, the value of the tag is checked. If its rate of change is greater than the maximum rate, a Rate of Change Alarm is triggered.

For example, to minimize the chance that a tank will fill too quickly you might configure a rate of change alarm, using a Rate of 300 liters, an [Alarm]Period of 60 seconds, and an [Alarm]ScanTime of 1 second. This means that the maximum allowable rate of change for the tank level is 5 l/sec (300 liters/60 seconds). The actual rate of change is calculated at each ScanTime; that is, every second it checks the current level of the tank and compares it to the level recorded a second earlier. If the actual rate of change is, say, 8 l/sec, a Rate of Change Alarm is triggered immediately.

This property is optional. If you do not specify a value, no Rate of Change Alarm is activated.

Deadband

The value that Variable Tag need to return to before the Alarm becomes inactive.

Format

The display format of the value (of the variable) when it is displayed on a graphics page, written to a file or passed to a function (that expects a string).

This property is optional. If you do not specify a format, the format defaults to the format specified for Variable tag.

Category

The alarm category number or label. This property is optional. If you do not specify a category, the alarm defaults to Category 0.

Help

The name of the graphics page that displays when the AlarmHelp() function is called by a user-defined command. This property is optional. If you don’t specify a help page, no action occurs when the AlarmHelp() function is called.

Comment

Any useful comment.

Extended forms fields

The following fields are implemented with extended forms (press F2).

Privilege

The privilege necessary by an operator to acknowledge or disable the alarm.

Note: If you assign an acknowledgment privilege to an alarm, do not assign a privilege to the command(s) that acknowledge the alarm. If you do assign a different privilege to the commands, then an operator needs to have both privileges to acknowledge the command.

Area

The area to which the alarm belongs. If an operator does not have access to an area, the alarm is not visible on the alarm display. For example, if you enter Area 1 here, operators need to have access to Area 1 (plus any necessary privileges) to acknowledge or disable this alarm.

Custom Filter1...Custom Filter8

A user-defined string for filtering active alarms (maximum 64 characters).

Used in a custom Cicode query function as search criteria, the custom alarm filter enables operators to identify and display a sub-set of active alarms.

Note:
• The custom filters are visible only when the Digital Alarms form is open in Extended mode.
• The fields are not case sensitive, and can contain 'A'..'Z', 'a'..'z', '0'..'9', and the underscore '_'.
• A custom filter cannot start with a digit.

Paging

A read/write property that indicates whether the alarm will be paged. When the value is 1 (TRUE) the alarm will be paged. The default value is 0 (FALSE). See Alarm Paging Properties. This property can be read using alarm tag browsing and read or modified when tag properties are enabled using the tag name "myCluster.myAlarm.paging".

Paging Group

A read only text string that indicates the paging group to which the alarm belongs. Maximum length is 80 characters. See your third-party paging system documentation for information on how to use this Paging Group string. This property can be read using alarm tag browsing or when tag properties are enabled read using the tagname "myCluster.myAlarm.paginggroup". For example, assign the value of PagingGroup to a variable:

myString = myCluster.Alarm_1.paginggroup

See Also