Rockwell Automation Logix5000 Controllers I/O and Tag Data Programming Manual - Manual (Page 23)

Organize tags Chapter 2
Term Definition
Data type The data type defines the type of data that a tag stores, such as a bit, integer, floating-point value,
string, and so forth.
Structure A data type that is a combination of other data types.
• A structure is formatted to create a unique data type that matches a specific need.
• Within a structure, each individual data type is called a member.
• Like tags, members have a name and data type.
• A Logix5000 controller contains a set of predefined structures (data types) for use with specific
instructions such as timers, counters, Function Blocks, and so forth.
• You can create your own structures, called a user-defined data type
The following table outlines the most common data types and when to use each.
For Select
Analog device in floating-point mode REAL
Analog device in integer mode (for very fast sample rates) INT
ASCII characters String
Bit BOOL
Counter COUNTER
Digital I/O point BOOL
Floating-point number REAL
Integer (whole number) DINT
Sequencer CONTROL
Timer TIMER
To Add Extended Properties
You have the option to add extended properties to select tags. The extended
properties include:
• Min
• Max
• Engineering Units
• State0
• State1
When these properties are added, their values are made available for use by some
Rockwell Automation HMIs.
Extended properties for a tag are added and modified in the Tag Properties pane.
Data type
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