Create tag attribute files

TIP:
To perform these steps, you need to run the Rule Editor with administrative privileges.
By default, FactoryTalk Historian ME uses a tag attribute file named
FTHMETagDefault.xml
. It defines point attributes that will be assigned to the new points in the point creation process.
When you associate the tag attribute file with a rule file and use them to create points, all the points discovered with the rules from the rule file will take on the attributes defined in the tag attribute file.
Instead of using the default tag attribute file, you may create your own.
To create a tag attribute file
  1. Go to
    Start > All Programs > Rockwell Software > FactoryTalk Historian ME Rule Editor > Launch Rule Editor
    .
    TIP:
    If you have logged on to the computer without administrative privileges, hold down Shift while clicking
    Launch Rule Editor
    with the right mouse button, and then click
    Run as administrator
    . Follow the on-screen instructions to run the program with administrative privileges.
    The
    FactoryTalk Historian ME Rule Editor
     window appears.
  2. Click
    Tag Attributes File Management
    .
    The
    FactoryTalk Historian ME Tag Attribute File List
     dialog box appears.
  3. Click
    New
    .
    The
    FactoryTalk Historian Tag Attribute
     dialog box appears.
  4. In the
    File Name
     box, type a name for the file.
    The file name may only contain the following characters: @, ., -, _, a-z, A-Z, 0-9, and must not contain any spaces.
  5. In the
    Description
     box, type a description for the file.
    You can use up to 80 characters.
  6. In the
    Scan class
     list, select a scan class, and the scan type.
    For details on scan classes, see Use scan classes.
    For details on scan types, see Configure scan types.
  7. In the
    Descriptor
     box, type a basic description of the point.
    The description will be displayed in client applications and user reports.
    The descriptor defined here will be listed in the
    Extended Description
     attribute of the point. For example, you can use this text as a basis for a tag search or in a trend display. It may be up to 65,535 characters long. When this value is read, it is truncated to the first 26 characters. Some interfaces use the descriptor for tag configuration in an external system. For those cases, do not use quotes or wildcards.
  8. In the
    Eng Units
     box, specify the unit of measure in the string format.
    The string may be of any length. However, when it is read, it is truncated to the first 12 characters. Engineering unit strings are case-preserving and case-insensitive. The system trims leading and trailing blank spaces during the input.
    If you use a single quote (') in a string, precede it with a double quote ("). Similarly, if you use a double quote in a string, precede it with a single quote.
  9. In the
    Display digits
     box, specify the format of numeric values in the Historian web client and in reports.
    A value equal to or greater than zero indicates the number of digits to display to the right of the decimal point.
    A value lower than zero indicates the number of significant digits to display. The number of significant digits that will be used is determined by calculating the absolute value of the value set in the
    Display digits
     box.
    The following table shows how 23.45 would appear on the screen depending on the value format set in the
    Display digits
     box:
    When Display digits is set to
    The value on the screen appears as
    3
    23.450
    2
    23.45
    1
    23.5
    0
    23.
    -1
    2E+001
  10. Click the
    Archive
     tab.
  11. In the
    Typical value
     box, type a reasonable value for a point.
    For a numeric tag, it must be greater than or equal to the value of the
    Zero
     attribute, and lower than or equal to the sum of the
    Zero
     and
    Span
     attribute values.
    The typical value range is between 0 and 100.
    The typical value range for the points of type
    Digital
     is between 0 and 1.
  12. In the
    Zero
     box, type the lowest value possible.
    This attribute is required for all numeric data type points. It does not have to be the same as the instrument zero, but that is usually a logical choice.
    The zero value range is between 0 and 100.
  13. In the
    Span
     box, set the difference between the top and the bottom of the range.
    This attribute is required for all numeric data type points.
    For
    Float16
     point types, the
    Span
     value is used with the
    Zero
     value for scaling values in the archive. The
    Span
     property must be a positive value. If the value for a
    Float16
     point type is greater than the top of the range, it is recorded in the archive as
    Over Range
    .
    For other point types, the
    Zero
     and
    Span
     values do not affect the values recorded in the archive. The
    Span
     property is also used when defining a FactoryTalk Historian ProcessBook trend with a vertical scale of database. This attribute is not used for non-numeric points.
  14. Under
    Step
    , choose either of the following to define the interpolation of numeric archived values:
    The value of the
    Step
     attribute also affects the compression calculation. When it is set to
    On
    , a linear change of a value greater than or equal to the value of the
    Compression Deviation
     attribute passes compression. This is essentially the same as the exception reporting. When the value of the
    Step
     attribute is set to
    Off
    , the complete swinging door algorithm is applied.
    Choose this item
    To treat the archived value as
    On
    A discrete value.
    Adjacent archived values are not interpolated and an archived value is assumed constant until the next archived value.
    For example:
    • At 12:00:00, the value 101.0 is archived.
    • At 12:01:00, the value 102.0 is archived.
    A request for the value at 12:00:30 would return 101.0.
    In general, data coming from discrete measurements, such as sampled laboratory data, batch charge weight, etc., should be archived in points with the
    Step
     attribute set to
    On
    .
    Off
    A continuous signal.
    Adjacent archived values are linearly interpolated.
    For example:
    • At 12:00:00, the value 101.0 is archived.
    • At 12:01:00, the value 102.0 is archived.
    A request for the archive value at 12:00:30 would return 101.5.
    In general, data coming from continuous signals, such as signals from thermocouples, flow meters, etc., should be archived in points with the
    Step
    attribute set to
    Off
    .
    This is the default setting.
  15. Under
    Shutdown
    , choose either of the following to configure shutdown events for a point:
    Choose this item
    To do the following
    On
    Record shutdown events for a data point.
    FactoryTalk Historian ME will automatically add a shutdown event with the timestamp of the Historian ME server shutdown to a point. In some cases, it is useful to record to FactoryTalk Historian ME points when the archive was shut down to indicate a gap in the data collection.
    This is the default setting.
    Off
    Leave a data point without recording the shutdown events.
  16. Under
    Compressing
    , set the data compression configuration.
    FactoryTalk Historian ME uses compression specifications to filter the data passed from the snapshot subsystem to the archive subsystem. The snapshot subsystem stores the most recent value for each data point. This most recent value is called the snapshot for that point. The snapshot subsystem uses compression specifications to determine which of the values that it has received get saved in the archive subsystem. By filtering out data that you do not need, your archive storage gets more efficient.
    The compression affects
    Digital
     point types, since a new value is recorded only when the current value changes. For
    String
     point types, new points pass compression only when the value changes.
    Choose either of the following:
    Choose this item
    To
    On
    Turn the data compression on for all real-time points in the system.
    This is the default setting,
    Off
    Turn the data compression off for laboratory and manually entered points so that all values are archived.
    When the
    Compressing
     attribute is set to
    Off
    , all points are archived.
  17. Under
    Exception Deviation
    , configure which point values are sent to the server:
    FactoryTalk Historian ME uses exception specifications so that the interface sends the data you are interested in to the server, rather than sending a lot of data that is not meaningful. The process of using exception specification to control the flow of data from the interface to the server is called exception reporting. It takes place on the interface before the data is sent to the server.
    1. In the first text box, type a value for the exception deviation.
      The value defines how much a value of a point must change before it is considered a significant value and sent to the server.
      As a general rule, set the exception deviation slightly smaller than the precision of the instrument system.
      You can set the value in engineering units or as a percentage of the
      Span
       value.
    2. In the list, choose either of the following:
      • If you have set the
        Exception Deviation
         value in engineering units, choose
        Eng. Units
        .
      • If you have set the
        Exception Deviation
         value as a percentage, choose
        % of Span
        .
    3. In the
      Min Time
       boxes, specify how frequently the interface can report values to the server.
      For example, if you want the interface to wait full 10 minutes before reporting a new value to the server, set the attribute to 10 minutes.
      Usually, this attribute is set to 0.
    4. In the
      Max Time
       boxes, specify how long the interface can go without reporting a value to the server. As soon as the time limit set in this attribute elapses, the interface sends the next new value to the server regardless of whether the new value is different from the last reported value. This may result in sending duplicated data.
      For
      Digital
       or
      String
       point types, only the exception maximum and exception minimum attributes are important. The exception deviation value is ignored by the Historian module.
  18. Under
    Compression Deviation
    , configure which point values are sent to the archive.
    FactoryTalk Historian ME uses the compression configuration to specify which data is archived.
    1. In the first text box, type a value for the compression deviation.
      The value defines how much a value of a point must change before it is considered a significant value and sent to the archive.
      As a general rule, set the compression deviation to the precision of the data source or hardware (instrument). After collecting data for a while, go back and check the data for your most important tags and adjust the value of the attribute, if necessary.
      Set the value with care. If you set the value too low, too little compression is imposed on data and a lot of space is wasted in the archive. If you set the value too high, you may lose important data.
      You can set the value in engineering units or as a percentage of the
      Span
       value.
      For regular flows, pressures, and levels, you can set the compression deviation to 1% or 2% of the
      Span
       attribute value. For temperatures, use 1 or 2 degrees.
    2. In the list, choose either of the following:
      • If you have set the
        Compression Deviation
         value in engineering units, choose
        Eng. Units
        .
      • If you have set the
        Compression Deviation
         value as a percentage, choose
        % of Span
        .
    3. In the
      Min Time
       boxes, specify how frequently the data is archived.
      A point is archived if the time that elapsed since the last archiving equals to or is greater than the
      Min Time
       value, and the value of the point has changed by more than the value of the
      Exception Deviation
       attribute.
      For data points associated with interfaces that send exception reports, set this value to 0.
    4. In the
      Max Time
       boxes, specify the time break without archiving the data.
      A point is archived if the time that elapsed since the last archiving is greater than the
      Max Time
       value. As soon as the time limit set in this attribute elapses, the data is archived regardless of whether the new value is different from the last archived value. This may result in archiving duplicated data.
      The recommended value is one work shift (for example, 8 hours). Typically, you should set the same
      Max Time
       value to all the points in the system.
      For
      Digital
       or
      String
       point types, only the compression maximum and compression minimum attributes are important. The compression deviation value is ignored by the Historian module.
  19. Click
    OK
    .
  20. The file is listed in the
    FactoryTalk Historian Tag Attribute File List
     dialog box.
    Tag attribute files are stored in the same location as the point discovery rule files:
    C:\Users\<User Name>\Documents\Rockwell Automation\RuleEditor\
    The names of the custom tag attribute files are preceded with a
    TCFG_
     prefix.
  21. After the tag attribute file has been created, you must upload the file to FactoryTalk Historian ME. You must have administrator privileges to upload files.
Now you can upload your file to the Historian module. For details, see Upload files to the module.
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