k = dcGain(zp); (k, finite) = dcGain(zp);
This function computes the steady state gain k of a ZerosAndPoles transfer function g(s), i.e. k = g(s=0). For a stable transfer function, a step input u results in the output y(t->t∞) = k.
If the transfer function has one or more zero poles, k is infinite. In this case, the output argument finite = false and k = Modelica.Constants.inf.
encapsulated function dcGain import Modelica_LinearSystems2.StateSpace; import Modelica_LinearSystems2.ZerosAndPoles; input ZerosAndPoles zp "ZerosAndPoles transfer function of a system"; output Real k "Steady state gain"; output Boolean finite = true "True, if k is finite, otherwise if k is infinite (k=Modelica.Constants.inf returned)"; end dcGain;