Integrator with limited value of the output and optional reset


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

This blocks computes y as integral of the input u multiplied with the gain k. If the integral reaches a given upper or lower limit and the input will drive the integral outside of this bound, the integration is halted and only restarted if the input drives the integral away from the bounds.

It might be difficult to initialize the integrator in steady state. This is discussed in the description of package Continuous.

If parameter limitAtInit = false, the limits of the integrator are removed from the initialization problem which leads to a much simpler equation system. After initialization has been performed, it is checked via an assert whether the output is in the defined limits. For backward compatibility reasons limitAtInit = true. In most cases it is best to use limitAtInit = false.

If the reset port is enabled, then the output y is reset to set or to y_start (if the set port is not enabled), whenever the reset port has a rising edge.

Parameters (9)


Value: 1

Type: Real

Description: Integrator gain



Type: Real

Description: Upper limit of output


Value: -outMax

Type: Real

Description: Lower limit of output


Value: false

Type: Boolean

Description: =true, if reset port enabled


Value: false

Type: Boolean

Description: =true, if set port enabled and used as reinitialization value when reset


Value: Modelica.Blocks.Types.Init.InitialState

Type: Init

Description: Type of initialization (1: no init, 2: steady state, 3/4: initial output)


Value: true

Type: Boolean

Description: = false, if limits are ignored during initialization (i.e., der(y)=k*u)


Value: 0

Type: Real

Description: Initial or guess value of output (must be in the limits outMin .. outMax)


Value: false

Type: Boolean

Description: = true, if strict limits with noEvent(..)

Connectors (4)


Type: RealInput

Description: Connector of Real input signal


Type: RealOutput

Description: Connector of Real output signal


Type: BooleanInput

Description: Optional connector of reset signal


Type: RealInput

Description: Optional connector of set signal