Clock triggered blocks for describing synchronous behavior suited for implementation of control systems

Package Contents


User's Guide


Library of examples to demonstrate the usage of package Modelica.Clocked


Library of blocks for clocked signals


Library of clocked blocks for Real signals


Library of clocked blocks for Integer signals


Library of clocked blocks for Boolean signals


Library of types with choices, especially to build menus


This information is part of the Modelica Standard Library maintained by the Modelica Association.

Library Modelica.Clocked is a Modelica package to precisely define and synchronize sampled data systems with different sampling rates. The library has elements to define periodic clocks and event clocks that trigger elements to sample, sub-sample, super-sample, or shift-sample partitions synchronously. Optionally, quantization effects, computational delay or noise can be simulated. Continuous-time equations can be automatically discretized and utilized in a sampled data system. The sample rate of a partition need to be defined only at one location.

In the following example a simple sampled data system is shown, where the borders of the discrete-time partition are marked by the sample and hold operators, a clocked PI controller is used in the partition and the sample rate is defined at one location with a clock:

Simple sampled-data system

The initial version of this library was developed and released under the name Modelica_Synchronous library before the library became a package of the Modelica Standard Library using the name Modelica.Clocked. The basic principles and components are the same as in the initial library, therefore the introductory material for Modelica_Synchronous is still valid, in particular:


  • User's Guide discusses the most important aspects of this library.
  • Release Notes summarizes the changes of the library releases.
  • Contact gives author and acknowledgement information for this library.

Copyright © 2012-2020, Modelica Association and contributors.

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Date Description
Aug. 28, 2012
DLR logo Initial version implemented by M. Otter and B. Thiele released as Modelica_Synchronous (version 0.9) library.
DLR Institute of System Dynamics and Control
Several releases as Modelica_Synchronous library.
2019 The Modelica_Synchronous library is included as Modelica.Clocked in the Modelica Standard Library 4.0.0.
see Release Notes.