Only mark states as changeable if the start attribute is constant

Compiler/BackEnd/BackendVariable.mo

@@ -333,6 +333,21 @@ algorithm
   end match;
 end varHasConstantBindExp;
 
+public function varHasConstantStartExp
+"Returns the true if the binding/start value is constant otherwise false."
+  input BackendDAE.Var v;
+  output Boolean out;
+protected
+  DAE.Exp e;
+algorithm
+  try
+    e := varStartValueFail(v);
+    out := Expression.isConst(e);
+  else
+    out := true;
+  end try;
+end varHasConstantStartExp;
+
 public function varHasBindExp
 "Returns the true if a bindExp exists otherwise false."
   input BackendDAE.Var v;

Compiler/SimCode/SimCodeUtil.mo

@@ -8514,10 +8514,11 @@ algorithm
         aliasvar = getAliasVar(dlowVar, optAliasVars);
         caus = getCausality(dlowVar, vars);
         numArrayElement = List.map(inst_dims, ExpressionDump.dimensionIntString);
+        isValueChangeable = BackendVariable.varHasConstantStartExp(dlowVar);
         // print("name: " + ComponentReference.printComponentRefStr(cr) + "indx: " + intString(indx) + "\n");
       then
         SimCodeVar.SIMVAR(cr, kind, commentStr, unit, displayUnit, -1 /* use -1 to get an error in simulation if something failed */,
-        minValue, maxValue, initVal, nomVal, isFixed, type_, isDiscrete, arrayCref, aliasvar, source, caus, NONE(), numArrayElement, true, isProtected, hideResult, NONE());
+        minValue, maxValue, initVal, nomVal, isFixed, type_, isDiscrete, arrayCref, aliasvar, source, caus, NONE(), numArrayElement, isValueChangeable, isProtected, hideResult, NONE());
 
     case ((BackendDAE.VAR(varName = cr,
       varKind = kind,
@@ -12797,7 +12798,7 @@ algorithm
 
   for param in inParamSimVars loop
     // take for now only parameters that are changeable and topLevel
-    if param.isValueChangeable == true and ComponentReference.crefIsIdent(param.name) then
+    if param.isValueChangeable and ComponentReference.crefIsIdent(param.name) then
       countSensitivityParams := countSensitivityParams+1;
       sensitivityParams := param::sensitivityParams;
       for state in inStateSimVars loop