The Integrator is, so to speak, the core component of ModelicaDEVS.
Its purpose is to integrate a (piecewise constant) function
originating from another DEVS block that is connected to the
Integrator's input port.
The picture illustrating the behaviour of the Integrator shows a
sine signal (blue), the integrated sine function (red), its first
derivative (green) and its second derivative devided by 2
(pink).
.ModelicaDEVS.FunctionBlocks.IntegratorQSS3