diff --git a/Compiler/BackEnd/BackendDAE.mo b/Compiler/BackEnd/BackendDAE.mo
index 399a417e0de..70e639dfd30 100644
--- a/Compiler/BackEnd/BackendDAE.mo
+++ b/Compiler/BackEnd/BackendDAE.mo
@@ -227,6 +227,9 @@ uniontype VarKind "variable kind"
   record OPT_INPUT_WITH_DER end OPT_INPUT_WITH_DER;
   record OPT_INPUT_DER end OPT_INPUT_DER;
   record OPT_TGRID end OPT_TGRID;
+  record OPT_LOOP_INPUT
+    .DAE.ComponentRef replaceExp; 
+  end OPT_LOOP_INPUT;
 end VarKind;
 
 public uniontype TearingSelect
diff --git a/Compiler/BackEnd/BackendDump.mo b/Compiler/BackEnd/BackendDump.mo
index f6fda18cc25..a08d3b3b333 100644
--- a/Compiler/BackEnd/BackendDump.mo
+++ b/Compiler/BackEnd/BackendDump.mo
@@ -2302,6 +2302,7 @@ algorithm
     case BackendDAE.OPT_INPUT_WITH_DER()  then "OPT_INPUT_WITH_DER";
     case BackendDAE.OPT_INPUT_DER()  then "OPT_INPUT_DER";
     case BackendDAE.OPT_TGRID()  then "OPT_TGRID";
+    case BackendDAE.OPT_LOOP_INPUT()  then "OPT_LOOP_INPUT";
   end match;
 end kindString;
 
diff --git a/Compiler/BackEnd/BackendVariable.mo b/Compiler/BackEnd/BackendVariable.mo
index 49a1739b572..baf4f1e5419 100644
--- a/Compiler/BackEnd/BackendVariable.mo
+++ b/Compiler/BackEnd/BackendVariable.mo
@@ -862,6 +862,7 @@ algorithm
     case (BackendDAE.VAR(varKind=BackendDAE.OPT_INPUT_WITH_DER())) then ();
     case (BackendDAE.VAR(varKind=BackendDAE.OPT_INPUT_DER())) then ();
     case (BackendDAE.VAR(varKind=BackendDAE.OPT_TGRID())) then ();
+    case (BackendDAE.VAR(varKind=BackendDAE.OPT_LOOP_INPUT())) then ();
   end match;
 end failIfNonState;
 
@@ -973,6 +974,7 @@ algorithm
     case ((BackendDAE.VAR(varKind=BackendDAE.OPT_INPUT_WITH_DER()) :: _)) then true;
     case ((BackendDAE.VAR(varKind=BackendDAE.OPT_INPUT_DER()) :: _)) then true;
     case ((BackendDAE.VAR(varKind=BackendDAE.OPT_TGRID()) :: _)) then true;
+    case ((BackendDAE.VAR(varKind=BackendDAE.OPT_LOOP_INPUT()) :: _)) then true;
     case ((_ :: vs)) then hasContinousVar(vs);
     case ({}) then false;
   end match;
@@ -991,12 +993,21 @@ algorithm
     /* Real non discrete variable */
     case (BackendDAE.VAR(varKind = kind, varType = DAE.T_REAL(_,_))) equation
       kind_lst = {BackendDAE.VARIABLE(), BackendDAE.DUMMY_DER(), BackendDAE.DUMMY_STATE(), BackendDAE.OPT_INPUT_WITH_DER(), BackendDAE.OPT_INPUT_DER()};
-    then listMember(kind, kind_lst);
+    then listMember(kind, kind_lst) or isOptLoopInput(kind);
 
     else false;
   end match;
 end isVarNonDiscreteAlg;
 
+protected function isOptLoopInput
+  input BackendDAE.VarKind kind;
+  output Boolean b;
+algorithm
+  b := match(kind) case(BackendDAE.OPT_LOOP_INPUT()) then true;
+                   else false;
+       end match;
+end isOptLoopInput;
+
 public function isVarDiscreteAlg
   input BackendDAE.Var var;
   output Boolean result;
diff --git a/Compiler/BackEnd/DynamicOptimization.mo b/Compiler/BackEnd/DynamicOptimization.mo
index 11b620c776c..72d199bcd2a 100644
--- a/Compiler/BackEnd/DynamicOptimization.mo
+++ b/Compiler/BackEnd/DynamicOptimization.mo
@@ -201,7 +201,7 @@ protected function makeVar "author: Vitalij Ruge"
 
 algorithm
   cr := ComponentReference.makeCrefIdent(name, DAE.T_REAL_DEFAULT, {});
-  v :=  BackendDAE.VAR(cr, BackendDAE.VARIABLE(), DAE.OUTPUT(), DAE.NON_PARALLEL(), DAE.T_REAL_DEFAULT, NONE(), NONE(), {}, DAE.emptyElementSource, NONE(), NONE(), NONE(), DAE.NON_CONNECTOR(), DAE.NOT_INNER_OUTER());
+  v :=  BackendDAE.VAR(cr, BackendDAE.VARIABLE(), DAE.OUTPUT(), DAE.NON_PARALLEL(), DAE.T_REAL_DEFAULT, NONE(), NONE(), {}, DAE.emptyElementSource, NONE(), SOME(BackendDAE.AVOID()), NONE(), DAE.NON_CONNECTOR(), DAE.NOT_INNER_OUTER());
 end makeVar;
 
 protected function addOptimizationVarsEqns1
@@ -652,13 +652,17 @@ algorithm
     // new input(resvar)
     (cr,var) := makeVar("OMC$Input" + intString(ind_v));
     var := BackendVariable.setVarDirection(var, DAE.INPUT());
-    var := BackendVariable.mergeAliasVars(var, var_, false, knvars);
-    oshared := BackendVariable.addKnVarDAE(var, oshared);
     // resvar = new input(resvar)
     e := Expression.crefExp(cr_var);
     if BackendVariable.isStateVar(var_) then
       e := Expression.expDer(e);
+      var := BackendVariable.setVarKind(var, BackendDAE.OPT_LOOP_INPUT(ComponentReference.crefPrefixDer(cr_var)));
+    else
+      // don't merge der(x) with x
+      var := BackendVariable.mergeAliasVars(var, var_, false, knvars);
+      var := BackendVariable.setVarKind(var, BackendDAE.OPT_LOOP_INPUT(cr_var));
     end if;
+    oshared := BackendVariable.addKnVarDAE(var, oshared);
     oeqns := BackendEquation.addEquation(BackendDAE.EQUATION(e, Expression.crefExp(cr), DAE.emptyElementSource, BackendDAE.EQ_ATTR_DEFAULT_UNKNOWN), oeqns);
 
   end for;
diff --git a/Compiler/SimCode/SerializeModelInfo.mo b/Compiler/SimCode/SerializeModelInfo.mo
index dd60448da5e..533aae7f106 100644
--- a/Compiler/SimCode/SerializeModelInfo.mo
+++ b/Compiler/SimCode/SerializeModelInfo.mo
@@ -766,6 +766,10 @@ algorithm
       equation
         File.write(file,"time grid for optimization");
       then ();
+    case BackendDAE.OPT_LOOP_INPUT()
+      equation
+        File.write(file,"variable for transform loop in constraint");
+      then ();
     else
       equation
         Error.addMessage(Error.INTERNAL_ERROR, {"serializeVarKind failed"});
diff --git a/Compiler/SimCode/SimCodeUtil.mo b/Compiler/SimCode/SimCodeUtil.mo
index 0bcce77ec1a..3c3f926e506 100644
--- a/Compiler/SimCode/SimCodeUtil.mo
+++ b/Compiler/SimCode/SimCodeUtil.mo
@@ -10004,6 +10004,11 @@ algorithm
     case (BackendDAE.VAR(varKind = BackendDAE.EXTOBJ(_), bindExp = SOME(e)))
     then SOME(e);
 
+    case (BackendDAE.VAR(values = dae_var_attr))
+    guard(BackendVariable.isVarNonDiscreteAlg(daelowVar))
+    then SOME(DAEUtil.getStartAttrFail(dae_var_attr));
+
+
     else NONE();
   end matchcontinue;
 end getStartValue;
diff --git a/Compiler/Template/CodegenC.tpl b/Compiler/Template/CodegenC.tpl
index c73aa8f8c1f..4e7386a0ed6 100644
--- a/Compiler/Template/CodegenC.tpl
+++ b/Compiler/Template/CodegenC.tpl
@@ -518,7 +518,7 @@ template simulationFile_opt_header(SimCode simCode, String guid)
       int <%symbolName(modelNamePrefixStr,"mayer")%>(DATA* data, modelica_real** res, short*);
       int <%symbolName(modelNamePrefixStr,"lagrange")%>(DATA* data, modelica_real** res, short *, short *);
       int <%symbolName(modelNamePrefixStr,"pickUpBoundsForInputsInOptimization")%>(DATA* data, modelica_real* min, modelica_real* max, modelica_real*nominal, modelica_boolean *useNominal, char ** name, modelica_real * start, modelica_real * startTimeOpt);
-      int <%symbolName(modelNamePrefixStr,"setInputData")%>(DATA *data);
+      int <%symbolName(modelNamePrefixStr,"setInputData")%>(DATA *data, const modelica_boolean file);
       int <%symbolName(modelNamePrefixStr,"getTimeGrid")%>(DATA *data, modelica_integer * nsi, modelica_real**t);
     #if defined(__cplusplus)
     }
@@ -644,7 +644,7 @@ template simulationFile(SimCode simCode, String guid)
     extern int <%symbolName(modelNamePrefixStr,"mayer")%>(DATA* data, modelica_real** res, short *);
     extern int <%symbolName(modelNamePrefixStr,"lagrange")%>(DATA* data, modelica_real** res, short *, short *);
     extern int <%symbolName(modelNamePrefixStr,"pickUpBoundsForInputsInOptimization")%>(DATA* data, modelica_real* min, modelica_real* max, modelica_real*nominal, modelica_boolean *useNominal, char ** name, modelica_real * start, modelica_real * startTimeOpt);
-    extern int <%symbolName(modelNamePrefixStr,"setInputData")%>(DATA *data);
+    extern int <%symbolName(modelNamePrefixStr,"setInputData")%>(DATA *data, const modelica_boolean file);
     extern int <%symbolName(modelNamePrefixStr,"getTimeGrid")%>(DATA *data, modelica_integer * nsi, modelica_real**t);
 
     struct OpenModelicaGeneratedFunctionCallbacks <%symbolName(modelNamePrefixStr,"callback")%> = {
@@ -10846,7 +10846,7 @@ template optimizationComponents( list<DAE.ClassAttributes> classAttributes ,SimC
         int <%symbolName(modelNamePrefixStr,"mayer")%>(DATA* data, modelica_real** res,short *i){return -1;}
         int <%symbolName(modelNamePrefixStr,"lagrange")%>(DATA* data, modelica_real** res, short * i1, short*i2){return -1;}
         int <%symbolName(modelNamePrefixStr,"pickUpBoundsForInputsInOptimization")%>(DATA* data, modelica_real* min, modelica_real* max, modelica_real*nominal, modelica_boolean *useNominal, char ** name, modelica_real * start, modelica_real * startTimeOpt){return -1;}
-        int <%symbolName(modelNamePrefixStr,"setInputData")%>(DATA *data){return -1;}
+        int <%symbolName(modelNamePrefixStr,"setInputData")%>(DATA *data, const modelica_boolean file){return -1;}
         int <%symbolName(modelNamePrefixStr,"getTimeGrid")%>(DATA *data, modelica_integer * nsi, modelica_real**t){return -1;}
         >>
       else
@@ -10897,6 +10897,12 @@ template optimizationComponents1(ClassAttributes classAttribute, SimCode simCode
           match modelInfo
             case MODELINFO(vars=SIMVARS(__)) then
             <<
+              if(file){
+              <%vars.inputVars |> SIMVAR(varKind = OPT_LOOP_INPUT(replaceExp=cr)) hasindex i0 =>
+              '<%cref(name)%> = <%cref(cr)%> ;'
+              ;separator="\n"
+              %>
+              }
               <%vars.inputVars |> SIMVAR(__) hasindex i0 =>
               'data->simulationInfo.inputVars[<%i0%>] = <%cref(name)%>;'
               ;separator="\n"
@@ -10954,7 +10960,7 @@ template optimizationComponents1(ClassAttributes classAttribute, SimCode simCode
              return 0;
            }
 
-           int <%symbolName(modelNamePrefixStr,"setInputData")%>(DATA *data)
+           int <%symbolName(modelNamePrefixStr,"setInputData")%>(DATA *data, const modelica_boolean file)
            {
             TRACE_PUSH
             <%setInput%>
diff --git a/Compiler/Template/SimCodeTV.mo b/Compiler/Template/SimCodeTV.mo
index 9bf5c338be5..3a4424fa5ac 100644
--- a/Compiler/Template/SimCodeTV.mo
+++ b/Compiler/Template/SimCodeTV.mo
@@ -945,6 +945,9 @@ package BackendDAE
     record OPT_INPUT_WITH_DER end OPT_INPUT_WITH_DER;
     record OPT_INPUT_DER end OPT_INPUT_DER;
     record OPT_TGRID end OPT_TGRID;
+    record OPT_LOOP_INPUT 
+      DAE.ComponentRef replaceExp; 
+    end OPT_LOOP_INPUT;
   end VarKind;
 
   uniontype ZeroCrossing
diff --git a/SimulationRuntime/c/openmodelica_func.h b/SimulationRuntime/c/openmodelica_func.h
index 37e8631743f..ddd58ce2a11 100644
--- a/SimulationRuntime/c/openmodelica_func.h
+++ b/SimulationRuntime/c/openmodelica_func.h
@@ -276,7 +276,7 @@ int (*pickUpBoundsForInputsInOptimization)(DATA* data, modelica_real* min, model
  * and set simulationInfo.inputVars. In case it's not present
  * a dummy function is added which return -1.
  */
-int (*setInputData)(DATA* data);
+int (*setInputData)(DATA* data, const modelica_boolean file);
 
 
 /*
diff --git a/SimulationRuntime/c/optimization/DataManagement/InitialGuess.c b/SimulationRuntime/c/optimization/DataManagement/InitialGuess.c
index dd9fdeac9e0..4ff741270d0 100644
--- a/SimulationRuntime/c/optimization/DataManagement/InitialGuess.c
+++ b/SimulationRuntime/c/optimization/DataManagement/InitialGuess.c
@@ -44,8 +44,8 @@
 
 static int initial_guess_ipopt_cflag(OptData *optData, char* cflags);
 static inline void smallIntSolverStep(DATA* data, SOLVER_INFO* solverInfo, const double tstop);
-static inline void initial_guess_ipopt_sim(OptData *optData, SOLVER_INFO* solverInfo, const short o);
-static inline void init_ipopt_data(OptData *optData);
+static short initial_guess_ipopt_sim(OptData *optData, SOLVER_INFO* solverInfo, const short o);
+static inline void init_ipopt_data(OptData *optData, const short o);
 
 /*!
  *  create initial guess
@@ -74,9 +74,9 @@ inline void initial_guess_optimizer(OptData *optData, SOLVER_INFO* solverInfo){
   }
 
   if(opt > 0)
-    initial_guess_ipopt_sim(optData, solverInfo, opt);
+    opt = initial_guess_ipopt_sim(optData, solverInfo, opt);
 
-  init_ipopt_data(optData);
+  init_ipopt_data(optData, opt);
 }
 
 
@@ -84,7 +84,7 @@ inline void initial_guess_optimizer(OptData *optData, SOLVER_INFO* solverInfo){
  *  create initial guess dasslColorSymJac
  *  author: Vitalij Ruge
  **/
-static inline void initial_guess_ipopt_sim(OptData *optData, SOLVER_INFO* solverInfo, const short o)
+static short initial_guess_ipopt_sim(OptData *optData, SOLVER_INFO* solverInfo, const short o)
 {
   double *u0;
   int i,j,k,l;
@@ -227,6 +227,7 @@ static inline void initial_guess_ipopt_sim(OptData *optData, SOLVER_INFO* solver
   data->simulationInfo.tolerance = tol;
 
   externalInputFree(data);
+  return op;
 }
 
 
@@ -272,7 +273,7 @@ static int initial_guess_ipopt_cflag(OptData *optData, char* cflags)
  *  init ipopt data struct
  *  author: Vitalij Ruge
  **/
-static inline void init_ipopt_data(OptData *optData){
+static inline void init_ipopt_data(OptData *optData, const short op){
   OptDataIpopt* ipop = &optData->ipop;
   DATA * data = optData->data;
   const int NV = optData->dim.NV;
@@ -301,7 +302,7 @@ static inline void init_ipopt_data(OptData *optData){
   for(i = 0, shift = 0; i < nsi; ++i){
     for(j = 0; j < np; ++j, shift+=nv){
       memcpy(data->localData[0]->realVars, optData->v[i][j], nReal*sizeof(double));
-      optData->data->callback->setInputData(optData->data);
+      optData->data->callback->setInputData(optData->data, op == 2);
       for(l = 0; l<nx; ++l){
         ipop->vopt[l + shift] = optData->v[i][j][l]*optData->bounds.scalF[l];
       }