Force a Variable

At run-timeIn computer science, runtime (or run-time) describes the operation of a computer program, the duration of its execution, from beginning to termination (compare compile time). Within KAS, runtime also refers to the virtual machine that manage the program written in a computer language while it is running, all variables in the table widget are animated 1 To better track variables and expressions of the PLC programs in test mode, the KAS IDE dynamically computes their value along with the execution and displays the result with real-time values.

You can double-click on the value of a variable (or press the ENTER key when it is selected) to open a pop-up window that allows you to:

• Force:
  change the value of the selected variable. Depending on the variable type, you have the possibility to define its value either in the text field or with the check boxes.
  

Figure 4-6: Forcing a variable

• Lock:
  Variables, member variables of a structure and variables in an array may be locked. When a variable is locked, its value is no longer changed by the runtimeIn computer science, runtime (or run-time) describes the operation of a computer program, the duration of its execution, from beginning to termination (compare compile time). Within KAS, runtime also refers to the virtual machine that manage the program written in a computer language while it is running. You can then force its value from the debugger independently from the runtime operations.
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  • The value of a locked variable is displayed with square brackets.
    

    

  The variable locking feature can be enabled or disabled via the PLC"Programmable Logic Controller" A Programmable Logic Controller, PLC, or Programmable Controller is a digital computer used for automation of industrial processes, such as control of machinery on factory assembly lines. Used to synchronize the flow of inputs from (physical) sensors and events with the flow of outputs to actuators and events Options device toolbar button. If enabled, the Lock and Unlock buttons are accessible:

  

  If disabled (default), the Lock and Unlock buttons are not accessible:

  

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  • If PLC variable locking is enabled, the controller RuntimeIn computer science, runtime (or run-time) describes the operation of a computer program, the duration of its execution, from beginning to termination (compare compile time). Within KAS, runtime also refers to the virtual machine that manage the program written in a computer language while it is running requires an additional 3% to 10% CPU processing power to manage the PLC variable locking. For the best controller performance, disable PLC variable locking.

• Unlock:
  Remove the lock on a variable so that it can be changed again by the runtime.