Searching for Errors in the User Application

The following are just some of the features provided to optimize debugging in the project:

  • Set breakpoints in the programming language editors

  • Step by step program execution, including step into, step out and step over

  • Call memory for recalling the entire program path

  • Control inputs and outputs

Online Mode

Online mode is when a connection is established between the PC and the PLC.

Online mode is used on the PLC for debugging, for animation and for changing the program.

A comparison between the project of the PC and project of the PLC takes place automatically when the connection is established.

This comparison can produce the following results:

  • Different projects on the PC and the PLC

    In this case, online mode is restricted. Only PLC control commands (e.g. start, stop), diagnostic services and variable monitoring are possible. Changes cannot be made to the PLC program logic or configuration. However, the downloading and uploading functions are possible and run in an unrestricted mode (same project on PC and PLC).

  • Same projects on the PC and the PLC

    There are two different possibilities:

    • ONLINE SAME, BUILT

      The last project generation on the PC was downloaded to the PLC and no changes were made afterwards, i.e. the projects on the PC and the PLC are absolutely identical.

      In this case, all animation functions are available and unrestricted.

    • ONLINE EQUAL, NOT BUILT

      The last project generation on the PC was downloaded to the PLC, however changes were made afterwards.

      In this case, the animation functions are only available in the unchanged project components.

Animation

Different possibilities are provided for the animation of variables:

  • Section animation

    All programming languages (FBD, LD, SFC, IL and ST) can be animated.

    The variables and connections are animated directly in the section.

  • Tooltips

    A tooltip with the value of a variable is displayed when the mouse pointer passes over that variable.

  • Inspection window

    An inspection window can be created for any variable. This window displays the value of the variable, the address and any comments (if available). This function is available in all programming languages.

  • Variables window

    This window displays all variables used in the current section.

  • Animation table

    The value of all variables in the project can be displayed, changed or forced in animation tables. Values can be changed individually or simultaneously together.

Watch Point

Watch points allow you to view PLC data at the exact moment at which it is created (1) and not only at the end of a cycle.

Animation tables can be synchronized with the watch point (2).

A counter (3) determines how often the watch point has been updated.

ST section with watch point:

Breakpoint

Breakpoints allow you to stop processing of the project at any point.

ST section with breakpoint:

Single Step Mode

Single step mode allows you to execute the program step by step. Single step functions are provided if the project was stopped by reaching a breakpoint or if it is already in single step mode.

ST section in single step mode:

The following functions are provided in single step mode:

  • Step by step execution of the program

  • StepIn (1)

  • StepOut

  • StepOver

  • Show Current Step (2)

  • Call memory (3)

    When the "step into" function is executed several times, the call memory enables the display of the entire path, starting with the first breakpoint

NOTE: Running the PLC program in step by step mode, as well as entering (StepIn) in a read/write protected section may lead to the inability to read the program and exit from the section. The user must switch the PLC in "Stop" mode to get back to the initial state.

Bookmarks

Bookmarks allow you to select code sections and easily find them again.