Subtype and Supertype

1 Connector Classes

type Voltage = Real(unit = "V");
type Current = Real(unit = "A");
connector Pin Voltage v; flow Current i; end Pin;

2 Resistor

The subtype relation between types is analogous to the subset relation between sets. If we have one type Temperature that contains all temperature values and another type Winter-Temperature that contains only negative temperature values, then we say that Temperature is a supertype of Winter-Temperature. This also implies that Winter-Temperature is a subtype of Temperature.

The supertype relation, on the other hand, is the inverse of the subtype relation. Since TempResistor is a subtype of Resistor, then Resistor is a supertype of TempResistor.

model Resistor Pin p, n "Positive and Negative Pins"; Voltage v; Current i; parameter Real R(unit = "Ohm") "Resistance"; equation v = R*i; end Resistor;
model TempResistor "Temperature dependent Resistor" Pin p, n "Positive and Negative Pins"; Voltage v; Current i; parameter Real R(unit = "Ohm") "Resistance at reference Temperature"; parameter Real RT(unit = "Ohm/degC") = 0 "Temperature dep. Resistance"; parameter Real Tref(unit = "degC") = 20 "Reference Temperature"; Real Temp = 20 "Actual Temperature"; equation v = i*(R + RT*(Temp - Tref)); end TempResistor;