Description of the Variables

This table shows the role of each type of variable.

Variable

Maximum number

Role

Public

unlimited

These internal variables of the DFB may be used by the DFB, by the application program and by the user in adjust mode.

Private

unlimited

These internal variables of the DFB can only be used by this function block, and are therefore not accessible by the application program, but these type of variables can be accessed by the data editor and the animation table.

These variables are generally necessary to the programming of the block, but are of no interest to the user (for example, the result of an intermediate calculation, etc.).
NOTE: Nested DFBs are declared as private variables of the parent DFB. So their variables are also not accessible through programming, but trough the data editor and the animation table.

Variables that Can Be Accessed by the Application Program

The only variables that can be accessed by the application program are public variables. To make this possible, the following syntax must be used in the program: DFB_Name.Variable_Name

DFB_Name represents the name of the instance of the DFB used (maximum of 32 characters),

Variable_Name represents the name of the public variable (maximum of 8 characters).

Example: Control.Gain indicates the public variable Gain of the DFB instance called Control

Saving Public Variables

Setting the %S94 system bit to 1 causes the public variables you have modified to be saved by program or by adjustment, in place of the initial values of these variables (defined in the DFB instances).

Replacement is only possible if the backup attribute is correctly set for the variable.