Tag
- Last UpdatedMar 10, 2025
- 7 minute read
Contains one row for each tag in the system and includes the basic definition for the tag, such as the I/O Server that supplies the values.
|
Column |
Data Type |
Description |
|---|---|---|
|
(PK) TagName |
TagNameType |
The unique name of the tag within the AVEVA Historian system. |
|
(FK) IOServerKey |
int, NULL |
The unique numerical identifier for the I/O Server. IOServerKey is a foreign key from the IOServer table. |
|
(PK) (FK) StorageNodeKey |
int NOT NULL |
The unique numerical identifier for the storage node. StorageNodeKey is a foreign key from the StorageNode table. |
|
wwTagKey |
int, NOT NULL |
The unique numerical identifier of a tag within a single AVEVA Historian. |
|
(FK) TopicKey |
int, NULL |
The unique numerical identifier for the topic. TopicKey is a foreign key from the Topic table. |
|
Description |
nvarchar(512), NULL |
The description of the tag. |
|
AcquisitionType |
tinyint, NOT NULL |
The method by which the tag's value is acquired. If the tag value is acquired from an I/O Server, specify the name of the I/O Server, topic, and item. 0 = Not acquired; 1 = Acquired via an I/O Server; 2 = Acquired via HCAL or MDAS or a manual update; 3 = System driver. |
|
StorageType |
smallint, NOT NULL |
The type of storage defined for the tag. 0 = Not stored; 1 = Cyclic; 2 = Delta; 3 = Forced storage; 17 = The storage type has been changed from cyclic to "not stored." 18 = The storage type has been changed from delta to "not stored." 19 = The storage type has been changed from "forced" to "not stored." |
|
StorageRate |
int, NOT NULL |
The rate at which the tag is stored if the storage type is cyclic. The rate is in milliseconds. |
|
ItemName |
nvarchar(256), NULL |
The address string of the tag. |
|
(FK) TagType |
int, NOT NULL |
The type of tag. 1 = Analog; 2 = Discrete; 3 = String; 5 = Event, 7 = Summary tag (analog or state). TagType is a foreign key from the TagRef table. |
|
TimeDeadband |
int, NULL |
The minimum time, in milliseconds, between stored values for a single tag. Any value changes that occur within the time deadband are not stored. The time deadband applies to delta storage only. A time deadband of 0 indicates that the system will store the value of the tag each time it changes. |
|
DateCreated |
datetime(2) 7, NOT NULL |
The date that the tag was created. If not specified, this date will be automatically generated. |
|
CreatedBy |
nvarchar(256), NOT NULL |
The name of the user or application that created the tag. If not specified, this name will be automatically generated. |
|
(FK) |
tinyint, NOT NULL |
Used to specify which application or editing environment controls the tag definition. Tags imported from the InTouch HMI software use InTouch as the current editor. If modifications are made to an imported tag in the historian Configuration Editor, then the current editor for the tag is changed to AVEVA Historian. If a re-import is performed, any modifications made using the Configuration Editor are preserved. You can manually maintain InTouch as the current editor for re-importing; however, all changes made to the tag using the Configuration Editor are lost during the re-import. Tags (attributes) that are initially configured using AVEVA Application Server use the ArchestrA Integrated Development Environment (IDE) as the current editor. If you modify an Application Server tag using the historian Configuration Editor, then the current editor for the tag is changed to AVEVA Historian. However, the next time you redeploy the engine, the changes are not preserved. 0 = AVEVA Historian; 1 = InTouch; 2 = AVEVA Application Server. |
|
Status |
tinyint, NULL |
Automatically updated by the system if a change is made to the replication group:
|
|
ServerTimeStamp |
bit, NOT NULL |
Used to indicate whether local timestamping by the AVEVA Historian is used. 0 = The IDAS timestamp is used; 1 = The AVEVA Historian time is used for the timestamp. If a fast-changing tag is configured to use server timestamping, the packet of data that is sent to the storage subsystem may contain multiple data values with the same timestamp, which may affect data calculations, such as for swinging door storage. |
|
DeadbandType |
smallint, NOT NULL |
The type of delta storage deadband to be applied for the tag. This setting is only in effect if delta storage is configured for the tag. 1= Time and/or value deadband; 2 = Rate (swinging door) deadband. |
|
CEVersion |
tinyint, NOT NULL |
The version number used to track changes to the information in the Tag table. Any change to the data in a row will cause the version indicator to change. The Configuration Editor (and other client tools) can detect the changed version and reload the corresponding tag details. Changes to this column are not tracked by the modification tracking system. |
|
TagId |
uniqueidentifier NOT NULL |
The unique identifier for the tag. |
|
(FK) ChannelStatus |
tinyint, NOT NULL |
Used for tags from AVEVA Application Server 2012 R2 or later or the AVEVA Historian SDK 2012 R2 or later. Used to specify how disconnects between these sources and the AVEVA Historian are reflected in the data until the disconnect period can be backfilled with store-and-forward data, if store-and-forward is enabled. 1 = Enabled. NULL values are injected into the data stream for the disconnect period. For a trend, this means that a line gap appears during the period of NULL values. The tag remains in store-and-forward mode until the timestamps become greater than the startup time of the server or the time that the connection was restored. 0 = Disabled. NULL values are not injected and no gap is shown in client-side trends. The channel status value is ignored for tags that use classic storage. ChannelStatus is a foreign key from ChannelStatus table. |
|
AIHistory |
bit, NOT NULL |
Used to indicate whether data exists for a tag in both storage and classic storage. 0 = No data was previously collected by classic storage; 1 = The tag may have data previously collected by classic storage. |
|
ChangeVersion |
timestamp, NOT NULL |
Internal use only. |
|
(FK) |
uniqueidentifier, NOT NULL |
The unique identifier for the partition (shard). |
|
ServerTimeStamp |
bit, NOT NULL |
Used to indicate whether local timestamping by the AVEVA Historian is used. 0 = The IDAS timestamp is used; 1 = The AVEVA Historian time is used for the timestamp. If a fast-changing tag is configured to use server timestamping, the packet of data that is sent to the storage subsystem may contain multiple data values with the same timestamp, which may affect data calculations, such as for swinging door storage. |
|
(FK) |
int, NULL |
The unique numerical identifier of a TRUE/FALSE message pair that can be associated with a discrete tag. MessageKey is a foreign key from the Message table. |
|
(FK) |
int, NULL |
The unique numerical identifier of an engineering unit. EUKey is a foreign key from the EngineeringUnit table. |
|
MinEU |
float, NULL |
The minimum value of the tag, measured in engineering units. |
|
MaxEU |
float, NULL |
The maximum value of the tag, measured in engineering units. |
|
MinRaw |
float, NULL |
The minimum value of the raw acquired value. |
|
MaxRaw |
float, NULL |
The maximum value of the raw acquired value. |
|
Scaling |
int, NULL |
The type of algorithm used to scale raw values to engineering units. For linear scaling, the result is calculated using linear interpolation between the end points. 0 = None; 1 = Linear; 2 = Square Root. (Square root is reserved for future use). |
|
RawType |
int, NULL |
The numeric type for the raw value. 1 = Euro Float, an outdated data type (4 bytes); 2 = MS Float (4 bytes); 3 = Integer (2 or 4 bytes); 4 = MS Double (reserved for future use) (8 bytes). |
|
ValueDeadband |
float, NULL |
The percentage of the difference between the minimum and maximum engineering units for the tag. Any data values that change less than the specified deadband are not stored. The value deadband applies to delta storage only. A value of 0 indicates that a value deadband will not be applied. |
|
IntegerSize |
tinyint,, NULL |
The bit size of the analog tag. 12 = 12-bit; 15 = 15-bit; 16 = 16-bit; 32 = 32-bit; 64 = 64-bit (reserved for future use). |
|
SignedInteger |
bit, NULL |
Used to specify whether an integer is a signed number (positive or negative) or an unsigned number (positive only). 0 = Unsigned; 1 = Signed. |
|
RateDeadband |
float, NULL |
The percentage of deviation in the full-scale value range for an analog tag. The swinging door (rate) deadband applies to delta storage only. Time and/or value deadbands can be used in addition to the swinging door deadband. Any value greater than 0 can be used for the deadband. A value of 0 indicates that a swinging door deadband will not be applied. |
|
InterpolationType |
tinyint, NULL |
The interpolation type for retrieval. 0 = Stair-stepped interpolation; 1 = Linear interpolation (if applicable, based on the tag type); 254 = System default interpolation mode. The system default interpolation type is to use the system default for the analog type, either integer or real. The system default interpolation type for an analog type is determined by the setting of the InterpolationTypeInteger and InterpolationTypeReal system parameters. This setting impacts Interpolated, Average, and Integral retrieval modes. |
|
RolloverValue |
float, NULL |
The first value that causes the counter to "roll over." This rollover value is used by the "counter" retrieval mode. For example, a counter that counts from 0 to 9999, the counter rolls over back to 0 for the 10,000th value it receives. Therefore, set the rollover value to 10,000. |
|
MaxLength |
smallint, NULL |
The maximum number of characters for the string. Valid values are: 8, 16, 24, 32, 48, 64, 128, 131, 256, 512. |
|
DoubleByte |
tinyint, NULL |
Used to store the string as a double-byte string. 0 = Not stored as double-byte; 1 = Stored as double-byte. The default is 0. |
|
(FK) |
uniqueidentifer, NULL |
The unique identifier for the structure. StructureId is a foreign key from the StructureType table. |
|
SourceTag |
nvarchar(256), NULL |
The name of the source tag used for the replication tag. |
|
SourceServer |
nvarchar(255), NULL |
The name of the tier 1 server with the source tag. |
|
SourceTagId |
uniqueidentifer, NULL |
The unique identifier for the source tag. |