Add a Time Stamped Alarm

Equipment

The name of the equipment associated with the time stamped alarm. Select a name from the drop-down list of existing equipment definitions, or enter a name.

There is a limit of 254 characters across the Equipment and Item Name fields, including any separating periods (.).

Item Name

The name of the item with which the alarm is associated.

Items form part of an equipment hierarchy. They can be used to associate tags, alarms and trends with a particular attribute of a physical piece of equipment (see Items).

There is a limit of 254 characters across the Equipment and Item Name, including any separating periods (.).

If you leave this field blank, the last 63 characters of the Alarm Tag field will be used for the Item Name. Be aware that the Alarm Tag allows 79 characters, while Tag Item has a maximum of 63 characters. This may result in compiler errors if the combination of '<Equipment>.<TagItem>' is not unique.

Note: When defining an item name, avoid using the reserved words. If you use any of these, an error message will display when you compile your project.

Alarm Tag

The name of the alarm tag. The name needs to be unique to the cluster and adhere to Tag Name Syntax rules.

If your project includes a large number of tags, a naming convention can be helpful when searching and debugging tags (see Structured Tag Names).

Alarm Name

A meaningful description of the alarm, for example, a name that includes the physical device associated with the alarm. The name is used when details of the alarm are displayed on the screen or logged to a device. This field does not support variable data.

Cluster Name

The name of the cluster that runs the alarm. This field needs to be defined if your project has more than one cluster.

You can leave this field blank in a multi-cluster system if cluster replication is enabled (see the parameter [General]ClusterReplication).

Category

The alarm category to which the alarm is assigned, defined as either a category number or a label (see Categorize Alarms).

If not specified, the category defaults to category 0.

Alarm Desc

A meaningful description of the alarm condition. This description is used when details of the alarm are displayed on screen or logged to a device.

This field can support variable data (by enclosing an expression in braces). For example:

Line Broken Alarm at Line Speed {LineSpeed1}

See Add Variable Data to Alarm Messages.

Timer Expr.

The variable tag or Cicode expression that represents the counter (or millisecond timer) configured in the I/O Device. The counter needs to be configured and maintained by the program in the I/O Device; it is read only when the alarm is triggered.

You can use one of three types of counter or timer to record the triggering of time-stamped alarms:

Continuous counter - A continuous counter is read in the unit to determine the sequence in which the alarms are triggered. The alarms are sorted based on the value of the counter when the alarm was triggered (the exact time is not recorded). Program the counter (in the unit) to count continually to its limit, reset, and again count to its limit.

Millisecond counter - If your unit supports a millisecond counter, program a counter (in the unit) to count (in milliseconds) for 24 hours, and then reset (at midnight). The value of this timer variable (in the unit) is read to determine the exact time when the alarm was triggered.

LONGBCB timer - Using a LONGBCD timer, you can log the exact time when a Time-stamped alarm becomes active. This variable is read, along with the alarm tag when the alarm activates. You need to program the LONGBCD variable in the following format with the range specified as hexadecimal numbers, excluding numbers containing alphabetic characters:

1st BYTE - Hours - 00-23 (most significant byte)

2nd BYTE - Minutes - 00-59

3rd BYTE - Seconds - 00-59

4th BYTE - 100th/sec - 00-99 (least significant byte)

Use 'Timer' to handshake with the PLC code: The PLC is informed that it has read the timer register and now the PLC can overwrite the last value. For example, with the following code saved in a Cicode file:

INT
FUNCTION
AlarmTimerReset(INT iTimer, STRING sTimerTrigger)
TagWrite(sTimerTrigger, 0);
//Reset the trigger
RETURN iTimer;
//Return the timer value to the alarm system
END

Example:

Where:

Variable Tag is AlmTrigger1 AND Timer is AlarmTimerReset(AlmTimer1, "AlmTrigger1")

In this example AlmTimer1 is the PLC register that stores the alarm time, and AlmTrigger1 is the alarm trigger bit.

When AlmTrigger1 is set to 1, the alarm is triggered, and the Cicode function is called. On calling the function, the AlmTimer1 register is read. The function resets the trigger bit (handshaking), and the value of AlmTimer1 is returned.

Note: AlarmTimerReset() is a user function that does not exist in Plant SCADA.

Timer Group

This field is only applicable if the parameter [Alarm]HresType is set to 1 (continuous counter).

It allows you to group alarms so that the alarm server can keep track of the counter sequence for each group independently. This may be useful if your system requires multiple alarm count sequences (to support multiple devices).

Help (Optional)

The name of the graphics page that displays when the AlarmHelp() function is called by a user-defined command. If not specified no action occurs when the AlarmHelp() function is called.

Comment

Any useful comment.

Variable Tag

The variable tag that triggers the alarm.

Custom 1 to Custom 8

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 subset of active alarms.

Note:

• Custom filters are visible only when the MultiDigital Alarm 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). 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

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, operator need to have access to Area 1 (plus any necessary privileges) to acknowledge or disable this alarm.

The area and privilege fields defined here needs to be designed to work in conjunction. A privilege defined on a button (say) will ignore the alarm defined area.

Privilege

Privilege necessary by an operator to acknowledge or disable the alarm.

If you assign an acknowledgment privilege to an alarm, you should also check the privilege that is assigned to the command(s) that acknowledge the alarm. If you assign a different privilege to the commands, an operator needs to have both privileges to acknowledge the command. More importantly, the area defined here may be ignored.

Historize

This field enables you to automatically historize and publish the specified time-stamped alarm in CitectHistorian.

If you set this field to "TRUE", the variable will be included in an automated configuration process within the Historian environment. If you set the field to "FALSE" (or leave it blank), the variable will not be included.

See Integration with Historian.

Project

The project in which the alarm is configured.