The following figure illustrates a TDL component (= module): a TDL module forms a unit that consists of sensors, actuators, and modes. A mode is a set of periodically executed activities. The activities are task invocations, actuator updates, and mode switches. All activities can have their own rate of execution and all activities can be executed conditionally. The tasks represent the functionality, particularly the control laws. As mentioned above any suitable language can be chosen to implement the functionality. If MathWorks’ tools are used, the functionality is modeled in Matlab®/Simulink®.

Actuator updates and mode switches are considered to be much faster than task invocations, thus they are executed in logical zero time. Whereas task invocations adhere to the socalled Logical Execution Time (LET) semantics.

© 2010 TDL Team