Variables

Variables in the entire project are grouped by:

Variable

Description

Global Variables

Lists all global variables used and accessible throughout the entire program.

Program Variables

Lists the variables related to your specific selected program.

Retain Variables

Lists all variables to be retained when the system is powered down.

For each variable, the Dictionary toolbox is used to set these parameters:

Field

Description

Attributes

The variable attributes are Read-only, External, IN, OUT.

  • Read-only: A variable set as Read Only is a constant.
    • It cannot be modified in the PLC code, but it can be manually forced.
    • Read-onlyvariables can be mapped to Inputs but not to Outputs.
      • Inputs can change state and a Read-only variable cannot change its value to match the input state.
  • External: this attribute is not used.
  • IN or OUT: Input or Output parameters of User Defined Function Blocks

Description

The variable description is a long comment text that describes the variable.

Dim.

  • To declare an array, specify dimensions for an internal variable.
  • See Arrays.

HMI

Init value

Name

The variable name.

Syb.

Reserved.

Tag

The variable tag is a short comment, that can be displayed together with the variable name in graphical editors.

Type

  • The variable type (can also be UDFB or complex structure).
  • See Data Types.

User Group

The variable user group (used for sorting variables).

Value