Importing/Exporting Tags

It is possible to export and import tags to/from an XML file format using the toolbar on the Tag Browser window. Simply click the Export button to export, or Import to load a previously exported file. Duplicate folders will be merged together, with new tags overwriting existing tags where there are duplications.

XML Structure

The basic structure of the xml file is as follows:

<Tags>

...

</Parameters>

</Alarm>

</Alarms>

</Permissions>

</Tag>

</Tags>

Tag Definition

Tags have three main attributes:

name - The name of the tag.

path - The folder path of the tag

type - The type of the tag (as in its function, not data type), which is one of the following values:

OPC

DB - Note: this is named this way for historical reasons. A "DB" tag is used to define Memory, Query, and Expression tags. The difference between these tags is defined by the presence and value of the "Expression" and "ExpressionType" properties (both being absent for memory tags).

Client

Folder

UDT_DEF - Type definition

UDT_INST - UDT Instance definition

EXTENSION - An override of a member defined in a parent type

Property Values

Tags (as well as sub elements, such as parameters and alarms) are defined by a collection of "Property" tags. The property generally consists of a name and value, though in some cases there might be additional attributes available.

Tag Properties

Property Name	Type	Values (if applicable)	Description
Value			The value of the tag, dependant on the data type.
DataType	Int	0 - Int1 1 - Int2 2 - Int4 3 - Int8 4 - Float4 5 - Float8 6 - Boolean 7 - String 8 - DateTime 9 - DataSet
Enabled	Booelan	true/false
AccessRights	Int	0 - Read Only 1 - Read/Write 2 - Custom	If custom, will be defined by a "permissions" tag.
OPCServer	String
OPCItemPath	String
OPCWriteBackServer	String		"Write back" target for expression tags.
OPCWriteBackItemPath	String
ScaleMode	Int	0 - Off 1 - Linear 2 - Square Root 3 - Exponential Filter
ScaleFactor	Float		For exponential filter
RawLow	Float		Defines scale range
RawHigh	Float
ScaledLow	Float
ScaledHigh	Float
ClampMode	Int	0 - None 1 - Low 2 - High 3 - Both
Deadband	Float
DeadbandMode	Int	0 - Absolute 1 - Percentage
FormatString	String
EngUnit	String
EngLow	Float
EngHigh	Float
EngLimitMode	Int	0 - None 1 - Low 2 - High 3 - Both
Tooltip	String
Documentation	String
ExpressionType	Int	0 - None 1 - Expression 2 - SQL Query
DriverName	String		Used for external tags
ScanClass	String
HistoryEnabled	Boolean	true/false
PrimaryHistoryProvider	String		The history provider to use if storing history
HistoricalDeadband	Float
HistoricalDeadbandMode	Int	0 - Absolute 1 - Percentage
HistoricalScanclass	String
InterpolationMode	Int	0 - Discrete 2 - Analog (deadband) 3 - Analog (compressed)	How values are interpolated. 2 exists for backwards compatibility (and is equivalent to 1), but only 0 or 3 should be used in the future.
HistoryTimestampSource	Int	0 - System 1 - Value
HistoryMaxAgeMode	Int	0 - Unlimited 1 - Limited
HistoryMaxAge	Int		Max cycles between storage.
UDTParentType	String		The path to the parent UDT type. Used by sub-types and instances.

Alarm Properties

Property Name	Type	Values (if applicable)	Description
Enabled	Boolean	true/false
Priority	String	Diagnostic, Low, Medium, High, Critical	May also be numeric, 0-4.
DisplayPath	String
ActivePipeline	String
ClearPipeline
Deadband	Float
DeadbandEvalMode	Integer	0 - Absolute 1 - Percentage
TimeOnDelaySeconds	Float		The "active delay"
TimeOffDelaySeconds	Float		The "clear delay"
TimestampSource	Int	0 - System 1 - Value
AckMode	Int	0 - Unused 1 - Auto 2 - Manual
Notes	String
AckNotesReqd	Boolean	true/false
ShelvingAllowed	Boolean	true/false
Mode	String	Equality Inequality AboveValue BelowValue BetweenValues OutsideValues OutOfEngRange BadQuality AnyChange Bit OnCondition
SetpointA			The setpoint, or the "low" setpoint for dual value modes.
SetpointB			The "high" setpoint for dual setpoint modes.
InclusiveA	Boolean
InclusiveB	Boolean
BitOnZero	Boolean		Used by the "Bit" condition, to indicate that 0 is "active"
BitPosition	Integer		Bit to use in "Bit" condition.
ActiveCondition	Boolean		The property that drives the "OnCondition" mode
AnyChange	Boolean		Whether or not to apply the "any change" behavior in applicable modes.

Binding Alarm Properties

The alarm properties can be bound to tags or expressions. To do this, set the "bindtype" attribute on the property to "Tag" or "Expression". The value will then either be a tag path (absolute or relative), or an expression.

User Defined Data Types (Complex Tags)

Complex tags are more or less defined like normal tags, but with a few important differences:

•	The tag type will be UDT_TYPE, UDT_INST, or EXTENSION.

•	The tag may contain nested tags, which will be the members.

•	Unless it is a top level type definition, the tag will have a "UDTParentType" property defined.

•	The tag may have a "Parameters" element, which will define the parameters. Each parameter will be a property, but the property may have a "type" attribute to define the type of the parameter. Valid types are "String", "Integer", and "Float".

•	Parameters are overridden by re-definition in sub-types. In other words, a <Parameters> element in a sub type with the same parameters names will override the parent parameters.

•	Member tag values are overridden by defining and "extension" tag in sub types.