Rockwell-automation Logix5000 Controllers I/O and Tag Data Programming Bedienungsanleitung PDF herunterladen (Seite 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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Rockwell-automation Logix5000 Controllers I/O and Tag Data Programming Bedienungsanleitung Seite 23