id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
4271	Loss of modification equations during transformation	Bernhard Thiele	Lennart Ochel	"Following state machine model has two states for which the input `xfoox` is provided by modification equations.

{{{#!modelica
loadString(""
model test
  StateX state1(xfoox=1.0);
  StateX state2(xfoox=0.1);
equation
  initialState(state1);
  transition(state1, state2, true, immediate=false);
  transition(state2, state1, true, immediate=false);
end test;

model StateX
  input Real xfoox;
  Real y;
equation
  y = xfoox * sample(1, Clock(1,10));
end StateX;
""); getErrorString();
simulate(test); getErrorString();
}}}

The problem is that after simulation both input variables `state1.xfoox` and `state2.xfoox` remain on their ""initial value"" 0. If one provides an explicit start value, e.g., `xfoox(start=0.1)`, that value is used instead. First analysis by Lennart and me suggests that the modification equations are ""lost"" either at the back-end transformation or the code generation."	defect	closed	high	Future	Backend		fixed		Rüdiger Franke Lennart Ochel lena.buffoni@…