https://reference.wolfram.com/system-modeler/libraries/Modelica/Modelica.Clocked.Examples.Elementary.RealSignals.AssignClockToSquareWaveHold.html
Modelica: Clocked.Examples.Elementary.RealSignals.AssignClockToSquareWaveHold - System Modeler...
Example of an AssignClockToSquareWaveHold block for Real signals
modelicaclockedexampleselementarysystem