Common Core Tag

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Introduction

The Common Core Tag serves as a common base for all other types of Tag.

Configuration Properties

The configuration properties of the Common Core Tag relate to its identification and its user rights:

Property Type Version Description
DriverName WSTRING 1.0 The name of the driver providing this tag.
Name WSTRING 1.0 The name of the tag within its folder.
ParentFolder WSTRING 3.74 The name of the folder that holds this tag.
TypeLabel WSTRING 1.0 A short description of the tag type.
TypeName WSTRING 1.0 The tag type name.
Description WSTRING 1.0 A description field where you can enter a description about the tag.
UserField1 WSTRING 1.0 A field where you can store application specific data.
UserField2 WSTRING 1.0 A field where you can store application specific data.
AlarmEventAreas WSTRING 4.2 A comma separated list of additional alarm and event areas this tag belongs to. For more information, see AlarmEventAreas Property below.
EventSeverity UINT 1.7 The severity of Event Log entries for state changes associated with this tag. A value of zero disables storage of state change events.
EventSeverityConfiguration UINT 3.25 The severity of Event Log entries for configuration changes associated with this tag. A value of zero disables storage of configuration change events.
EventSeverityOperator UINT 3.25 The severity of Event Log entries for operator actions associated with this tag. A value of zero disables storage of operator action events.
UserPrivileges DWORD 3.93 The privileges available to the current user for this tag. For more information, see UserPrivileges Property below.
UserRightsZone USINT 1.5 The security zone for the tag. For more information, see UserRightsZone Property below.

AlarmEventAreas Property

In Alarm and Event applications you can filter alarms and events by area. The folders that contain a tag are automatically alarm and event areas for the tag. The AlarmEventAreas property allows you to configure additional alarm and event areas.

For example, the tag "Flow Rate" in folder "Pump Room" in folder "Equipment" would have the full name:

Equipment.Pump Room.Flow Rate

This tag would automatically belong to these alarm and event areas:

If the AlarmEventAreas property was set to 'Flow Rates', the alarm and event areas for the tag would become:

You can configure multiple alarm and event areas using a comma to separate each alarm and event area. For example:

'Flow Rates', "Important Parameters"

The syntax of the AlarmEventAreas property is:

alarm-event-areas ::=
  [ alarm-event-area { , alarm-event-area }

alarm-event-area ::=
  identifier
  | single-quote-string
  | double-quote-string

See also Alarm Filter.

UserPrivileges Property

The UserPrivileges property is a bitmask of the privileges the user has for the tag.

BitMaskNameDescription
0 16#1 Refresh The user can request a data refresh.
1 16#2 Write The user can write to a data point tag.
2 16#4 Force The user force the value of a data point tag.
3 16#8 Acknowledge The user can acknowledge alarms.
4 16#10 DisableAlarm The user can disable and enable alarms.
5 16#20 DirectWrite The user can directly write to a device.
6 16#40 WriteFile The user can write a file to a device.
7 16#80 TuneAlarm The user can override, or restore, alarm limits.
8 16#100 Configure The user can configure the tag.

In an Operator Action, use this type of IF statement to check if a user has a certain privilege:

(* Check whether the user can write to the device... *)
IF (%"TagName.UserPrivileges" AND 16#2) <> 0 THEN

    (* The user can write to the device *)
    ....
END_IF

For more information see User Rights and Privileges.

UserRightsZone Property

The UserRightsZone property together with the User Rights define what each user can do with each tag. The UserRightsZone defines which security zone the tag belongs to. To change the rights assigned to users:

Data Properties

The Common Core Tag supports these data properties:

Property Type Description
Quality INT The quality of the data of this tag.
Timestamp DATE_AND_TIME The timestamp of the last update to the data of this tag.

Relationships to Other Tag Types

The Common Core Tag is used as a building block for these tag types:

Further Information

Glossary

For the meaning of terms used in Fernhill SCADA.