Variable Information

When you select a variable in the tree view, you will see dialogues giving information and settings options and an online dialogue with a Force Option below a task or an I/O device (in the following image, a PLC variable on the BC), on the right-hand side.

”Variable” tab

Variable Information 1:

Name

Defines the name of the variable selected in the tree view.

Type

Gives the Data Type of the current variable.

Group

Informs whether the variable is an input or an output.

Size

Gives the size of the variable in bytes.

Address

Displays the addresses of the variables in the process image. If, as in the example, another external address is given (e.g. for variables in the Bus Terminal controller), the value must be added after "ext:" on the offset of the data exchange variables (as defined in "PLC" Dialogue).

User ID

A user-defined number for future System Manager functions.

Linked to

Indicates if applicable the variable linked with the selected variable. Actuate this button to display the Selection Diagram for the variable link.

Comment

User-defined comments field.

ADS Info

Provides information required to access selected variable via ADS (e.g. TwinCAT Scope View, …). The information comprises Port Number, Index Group, Index Offset and Variable Length in bytes.

”Flags” tab

Variable Information 2:

Swap LOBYTE and HIBYTE

Actuate this to exchange the values of the lower and higher Byte within the 16Bit variable. The result will be available for the process image (e.g. required for some 3rd party Profibus devices).

Swap LOWORD and HIWORD

Actuate this to exchange the values of the lower and higher Word within a 32Bit variable. The result will be available for the process image.

”Online” tab

Variable Information 3:

Value

Shows the current value of the selected variable.

Force

Displays the dialogue for forcing the variable. The overwritten value is retained until the command is cancelled using Remove or the TwinCAT system restarts. A forced variable value is shown in red.

Release

Releases the variable to its regular process image value.

Write

Displays the dialogue for changing the variable value to a user-defined value. In this case the value is overwritten just once for one task cycle.

Additionally, the variable value is shown in a graphical trace view (continuously), the so-called History View. This display gives an impression about time-based value changes of a variable. Additional infos about the History View can be found under: Settings for History View.