TwinCAT and Windows NT
Management of TwinCAT task execution und Windows process execution time
The following diagram illustrates an example of execution times of Windows NT based operating systems (Windows NT, Windows 2000, Windows XP,...)
The execution time for NT starts when task execution has finished, but at the latest halfway through the available period (50%). If execution of the task needs more time than the 50% that has been set, it is interrupted to give time to Windows NT, and completed in the following cycle. If no task is being run in any particular cycle, Windows NT can use 100% of the available computing time.
Management of TwinCAT task execution und Windows process execution time with various priorities
The following diagram illustrates an example of execution times with various priorities:
Task 1, which has higher priority, is run in every cycle. The remaining time available for task execution is used by Task 2 (which has lower priority). The execution time for Windows NT remains a constant 50% in each cycle.