Enter Tags and Aliases

When the I/O Module was added to the project the corresponding local tags were also added to project. All I/O tags are controller scoped.
TIP:
Select
File > New Component > Tag
 to create new tags using the
New Tag
 dialog .
If you create the new tag using this approach, choosing one of the data types AXIS, MOTION GROUP, MESSAGE, or PID,and a check box to open the configuration appears. Selecting this check box will open the properties configuration dialog that will lead you through the configuration of these data types.
Entering tags uses these items:
Item
Description
Tag Editor
The interface in Logix Designer that is used to create and manage tags. The background color of a cell indicates whether the cell is read only. A white background indicates that the cell is modifiable; gray indicates that the cell is read only.
Tag
A named area of the process-connected device or controller’s memory where data is stored. It is the basic mechanism for allocating memory, referencing data from logic, and monitoring data. Data stored in tags can be either:
  • Configuration - Designated by a :C in the tag name. Used to hold the module configuration.
  • Input - Designated by a :I in the tag name. Used to contain input data for the module.
  • Output - Designated by a :O in the tag name. Used to contain output data from the module.
Tags are of different types:
  • Base tags - The tag that defines where the memory is stored. Unless otherwise specified, all new tags are base tags. You can create base tags while the controller is online or offline if the new tag can be verified..
  • Alias tags - A tag that references memory defined by another tag. An alias tag may refer to another alias tag or a base tag. An alias tag may also refer to memory within another tag by referencing a member of a structure tag, or a bit within an integer tag or member. You can create alias tags while the controller is online or offline if the new tag can be verified.
  • Produced tags - A tag that a controller makes available for use by other controllers. Produced tags are always at controller scope.
  • Consumed tags - A tag whose value comes from a remote controller. The local controller is the consumer, and the remote controller is the producer. Consumed tags are always at controller scope. You can create consumed tags only while the controller is offline.
Data types
The controller supports the elementary data types defined in IEC 1131-3 defined data types. The predefined, atomic data types are BOOL, SINT, INT, DINT, and REAL. The controller handles all immediate values as DINT data types. There are categories of pre-defined data types associated with different data structures that can be selected.
Scope
The level at which tags and routines may be created. They can be created at the controller level (accessible to all routines), or at the program level (accessible to only the routines within a single program).
External access
The access rights that tag will have from external applications, such as HMIs.
OPC UA Access
Used to select the level of access that external OPC UA clients have to tags.
Constant
Defines the tag as a constant value which prevent executing logic from writing values to the tag.
Style
The form in which numeric values can be displayed. The table provides you with information on the base and notation used for each style.
Style
Base
Notation
Binary
2
2#
Decimal
10
NA
Hexadecimal
16
16#
Octal
8
8#
Exponential
NA
0.0000000e+000
Float
NA
0.0
To edit tags and aliases
  1. Right-click the
    Controller Tags
     folder in the
    Controller Organizer
    , and choose
    Edit Tags
    .
    The Tag Editor opens and displays a grid containing the default local tags.
  2. To create a new tag, in the create tag row at the bottom of the Tag Editor grid (indicated by the yellow tag icon), enter the name of the tag in the
    Name
     column. An asterisk (*) appears in the new tag row and the tag properties are displayed in the
    Tag Properties
     pane on the right side of the Tag Editor.
  3. In the
    Tag Properties
     pane review the properties of the tag. Expand the properties category to edit and view the properties:
    • General - The selected tag's general properties. This property category is expanded by default.
    • Data - The selected tag's data properties.
    • Produced Connection - The selected tag's produced connection properties.
    • Multicast - The selected tag's multicast properties. For safety and axis type tags, all the properties within this group are read-only.
    • Produced Connection Status - The selected tag's connection status properties.
    • Consumed Connection - The selected tag's consumed connection properties.
    • Safety - The selected tag's safety properties. This category is only displayed for safety projects.
    • Consumed Connection Status - The selected tag's connection status properties.
    • Parameter Connections {X:X} - The selected tag member's list of connections. The first number within {X:X} represents the number of connections to the tag member; the second number represents the total number of connections to all of the sub-members of the tag member.
  4. To create an alias tag, in
    Alias For
     enter the name of the tag to which this tag refers.
  5. To create a base tag, in
    Data Type
     click the ellipsis (...) button and select a data type.
  6. (optional) Select the scope for the tag. All tags are Controller Scoped by default.
  7. In
    External Access
     determine whether external application and devices will have Read/Write, Read Only, or no access to the tag.
  8. In
    OPC UA Access
     select the level of access (Read Only, Read/Write, or None) that external OPC UA clients have to tags.
  9. (optional) To establish a constant value for a tag, select
    Constant
     and then in
    Properties
     under
    Data
    , in
    Value
     type the value the tag is equal to. If a logic routine tries to write to a constant tag, the routine will not verify.
    TIP:
    The state of the
    Constant
    check box depends on the type of tag selected and is disabled under certain circumstances. A blue icon in the Value column of constant tags indicates that the tag is a Constant Value tag.
    The value fields in all other browsers and language editors are disabled when the tag is a Constant tag.
  10. In
    Style
    , choose how to display the value of the tag (Binary, Octal, Decimal, Hex, or ASCII).
    Based on the data type you selected, a default style is chosen automatically.
  11. Press Enter to move to the next row, which creates a new tag. If there is an error in the tag definition, a prompt appears.
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