id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
2755	Pantelides fails in a small model	massimo ceraolo	somebody	"I have a class of models for which the following error is issued (using OM r21397). 

[:0:0-0:0] Error: Internal error Transformation Module PFPlusExt index Reduction Method Pantelides failed!

Now I've created a small model (31 equations, 22 of which trivial), in which the issue occurs.
Maybe it is of use for the whole OM community to have this issue approached.
Here's the model:

{{{
model commTest0
  model Commutator
    parameter Integer m(final min = 1);
    Modelica.Electrical.Analog.Interfaces.PositivePin pin_pm[m];
    Modelica.Electrical.Analog.Interfaces.PositivePin pin_p;
    Modelica.Blocks.Interfaces.IntegerInput z;
  equation
    pin_p.v = pin_pm[z].v;
    for j in 1:m loop
      pin_pm[j].i = if j == z then -pin_p.i else 0;
    end for;
  end Commutator;

  Commutator commutator(m = 2);
  Modelica.Electrical.Analog.Basic.Resistor resistor(R = 2);
  Modelica.Electrical.Analog.Basic.Ground ground;
  Modelica.Electrical.Analog.Sources.ConstantVoltage E1(V = 100);
  Modelica.Electrical.Analog.Sources.ConstantVoltage E2(V = 200);
  Modelica.Blocks.Sources.IntegerConstant intConst(k = 1);
equation
  connect(commutator.pin_p, resistor.p);
  connect(resistor.n, ground.p);
  connect(E1.p, commutator.pin_pm[1]);
  connect(E2.p, commutator.pin_pm[2]);
  connect(E1.n, ground.p);
  connect(E2.n, ground.p);
  connect(commutator.z, intConst.y);
end commTest0;
}}}"	defect	closed	high		Backend	trunk	worksforme