Exception Handling

The compiler is used to write your own exception programs The act of performing a sequence of instructions or commands. for handling particular system events.

These are the exceptions:

• Division By Zero Exceptions.
• Shutdown Exceptions (after the last cycle).
  
• Startup Exceptions (before the first cycle).
  

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• Exception handling is supported for both Normal and Optimized PLC code generation.

• In the sub-program that handles the exception you can perform any safety or trace operation.
• Then, select between these possibilities:
  • Return without any special call.
    • In this case the standard handling is performed:
      • A system error message is generated.
      • The result of the division is replaced by a maximum value and the application continues.
  • Call the FatalStop function A function calculates a result according to the current value of its inputs. A function has no internal data and is not linked to declared instances..
    • The runtime In 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). In KAS, runtime refers to the virtual machine that manage the program written in a computer language while it is running. then stops immediately in Fatal Error mode.
  • Call the CycleStop function.
    • The runtime finishes the current program and then turns in "cycle setting" mode.

Handlers can also be used in DEBUG mode for tracking Characterized by an axis group that follows with its movement the movement of another axis group. the bad operation.

• Put a breakpoint in the handler.
  • When stopped, the call stack shows the location of the division in the source code of the program.

Division By Zero Exceptions

You can write your own exception program for handling the Division by zero exception.

In this procedure, you must follow for setting an exception handler:

1. Create a new sub-program without any parameter that will handle the exception.
2. In the editor of global defines, insert this line:

#OnDivZero SubProgramName

Shutdown Exceptions

You can write your own exception program to be executed after the last application cycle when the runtime system is cleanly stopped.

1. Create a new main program that handles the exception.
   It cannot be an SFC Sequential function chart - It can be used to program processes that can be split into steps. The main components of SFC are: - Steps with associated actions. - Transitions with associated logic conditions. - Directed links between steps and transitions. program.
2. In the editor of global defines, insert this line:

#OnShutdown ProgramName

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• You cannot put breakpoints in the Shutdown program.

Startup Exceptions

You can write your own exception program to be executed before the first application cycle is executed.

1. Create a new main program that will handle the exception.
   
   It cannot be an SFC program.
2. In the editor of global defines, insert this line:

#OnStartup ProgramName

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• The program is executed before all other programs within the first cycle.
  This implies that the cycle timing can be longer during the first cycle.
  You cannot put breakpoints in the Startup program.