At a Glance
A breakpoint can be used to stop the execution of the task which contains the DFB instance in which it has been set.
During debugging it can be used:
to examine the behavior of the code,
to view the value of the variables and the input/output parameters of the instance.
There is a single breakpoint at a given point in the project. This is not saved and is lost on disconnection from the PLC.
It is implemented in online mode regardless of whether the PLC is in Run or in Stop.
Elements Used for Setting a Breakpoint
The program element used to set a breakpoint in a DFB section depends on the language in which the section has been written:
the rung and the nested DFB call for Ladder Diagram language,
the instruction for textual languages,
the Function Block for Function Block Diagram language.
How to Insert a Breakpoint
Access the DFB instance section from which you wish to insert a breakpoint.
Depending on the language used in the DFB section, proceed in the following manner:
If several instances of a DFB are used in the application, the breakpoint is valid for all calls as the DFB code is shared by all the instances.
The task corresponding to the first call (order of execution) is stopped when the breakpoint in reached.
By relaunching execution using the Go button 
the task corresponding to
the next call is stopped and so on.
How to Locate an Existing Breakpoint
Carry out the following actions:
Step |
Action |
|---|---|
1 |
Select the following command from the menu: Debug->Show Breakpoint. |
2 |
The part of the language editor containing the breakpoint is displayed. |
How to Delete a Breakpoint
Either you can:
select the following command from the menu:
Debug->Clear Breakpoint,
or select the
button in the debug toolbar.
Erasing a breakpoint does not restart the task. To do this,
you have to press 
.