EventTag

(PK) (FK) TagName

TagNameType
(nvarchar(256)) NOT NULL

The unique name of the tag within the AVEVA Historian system. TagName is a foreign key from the Tag table.

(FK) DetectorTypeKey

int NULL

The unique identifier of a particular type of detector. Event tags and detectors are linked by means of this key. The event system relies on the following values, which are added during installation: 1 = System; 2 = External event; 3 = Generic SQL; 4 = Analog specific value; 5 = Discrete specific value; 6 = Time-based (schedule). DetectorTypeKey is a foreign key from the DetectorType table.

(FK) ActionTypeKey

int NULL

The unique identifier for a particular type of action. Event tags and actions are linked by this key. The event subsystem relies on the following values, which are added during installation: 1 = No action; 2 = Generic SQL; 3 = Snapshot; 4 = E-mail; 5 = Deadband; 6 = Summary. ActionTypeKey is a foreign key from the ActionType table.

ScanRate

int NULL

The interval, in milliseconds, at which the system checks to see if the event conditions specified by the detector occurred. This value must be greater than or equal to 500 milliseconds, and less than or equal to 1 hour (3600000 ms).

TimeDeadband

int NOT NULL

The minimum time, in milliseconds, between stored events. If more than one event occurs during the deadband, only the most recent will be stored. The system will not store another event until the specified time has elapsed. A time deadband of 0 indicates that the system will store all events. Reserved for future use.

Logged

bit NOT NULL

Used to specify whether or not to log events for this tag into the EventHistory table. Event logging can only be turned off if no associated actions are configured. 0 = Not logged; 1 = Logged. The default is 1.

Status

tinyint NOT NULL

The flag used by the event system at system startup and during runtime to determine if the event tag has been modified. 0 = Posted. Any changes have been detected and effected by the system. 1 = New. An event tag has been inserted, but is not yet executing. 2 = Modification. An event tag has been updated, but the older one is already executing. 98 = Disabled. 99 = Disabling requested. The event tag does not execute, even though the definition still exists in the schema. Note that there may be a delay of up to 30 seconds before a change in an event tag is seen by the running system.

PostDetectorDelay

int NOT NULL

The amount of time, in milliseconds, that must elapse after an event is detected before the event action can be executed.

UseThreadPool

bit NOT NULL

Used to specify how system threads are used to process events. 1 = All events are handled by a single thread and a single logon to the SQL Server; 0 = Each event uses a separate system thread and logon. This will allow the event subsystem to manage the scan rates of each detector component concurrently. (Reserved for future use.)

DetectorString

nvarchar(1500) NULL

The script that contains the criteria for event detection. Detector scripts are executed on the local AVEVA Historian.

ActionString

nvarchar(1500) NULL

The script that specifies the event action. Action scripts run on the local AVEVA Historian.

Priority

tinyint NOT NULL

The priority level for the action, either critical or normal. The priority level determines the sorting queue to which the action will be sent. The critical queue is used for highly important events. If a system overload condition occurs, events that are given a critical priority will always be processed first. Events that are given a normal priority will be processed after any critical events and may possibly be dropped (that is, not performed) on an overloaded system. 0 = Normal; 1 = Critical. The default is 0.

Edge

tinyint NOT NULL

The "edge" for the event detection. 0 = Trailing; 1 = Leading; 2 = Both; 3 = None; 4 = Time Detector; 5 = External Detector.