diff --git a/FDTD/operator.cpp b/FDTD/operator.cpp
index 80882b5..bd3aa47 100644
--- a/FDTD/operator.cpp
+++ b/FDTD/operator.cpp
@@ -69,6 +69,9 @@ void Operator::Init()
 		EC_L[n]=NULL;
 		EC_R[n]=NULL;
 	}
+
+	for (int n=0;n<6;++n)
+		m_BC[n]=0;
 }
 
 void Operator::Reset()
@@ -577,6 +580,11 @@ int Operator::CalcECOperator()
 	if (CalcEFieldExcitation()==false) return -1;
 	CalcPEC();
 
+	bool PMC[6];
+	for (int n=0;n<6;++n)
+		PMC[n] = m_BC[n]==1;
+	ApplyMagneticBC(PMC);
+
 	return 0;
 }
 
diff --git a/FDTD/operator.h b/FDTD/operator.h
index 120439d..ba202b3 100644
--- a/FDTD/operator.h
+++ b/FDTD/operator.h
@@ -53,6 +53,7 @@ public:
 	//! Get the excitation timestep with the (first) max amplitude
 	virtual unsigned int GetMaxExcitationTimestep() const;
 
+	virtual void SetBoundaryCondition(int* BCs) {for (int n=0;n<6;++n) m_BC[n]=BCs[n];}
 	virtual void ApplyElectricBC(bool* dirs); //applied by default to all boundaries
 	virtual void ApplyMagneticBC(bool* dirs);
 
@@ -104,6 +105,8 @@ protected:
 
 	ContinuousStructure* CSX;
 
+	int m_BC[6];
+
 	//E-Field Excitation
 	//!	  Calc the electric field excitation.
 	virtual bool CalcEFieldExcitation();
diff --git a/openems.cpp b/openems.cpp
index 8a0f6ce..63434e6 100644
--- a/openems.cpp
+++ b/openems.cpp
@@ -237,10 +237,6 @@ int openEMS::SetupFDTD(const char* file)
 		return(-2);
 	}
 
-	bool PMC[6];
-	for (int n=0;n<6;++n)
-		PMC[n]=(bounds[n]==1);
-
 	//*************** setup operator ************//
 	cout << "Create Operator..." << endl;
 	if (CylinderCoords)
@@ -255,8 +251,10 @@ int openEMS::SetupFDTD(const char* file)
 
 	if (FDTD_Op->SetGeometryCSX(&CSX)==false) return(2);
 
+	FDTD_Op->SetBoundaryCondition(bounds); //operator only knows about PEC and PMC, everything else is defined by extensions (see below)
+
 	/**************************** create all operator/engine extensions here !!!! **********************************/
-	//Mur-ABC
+	//Mur-ABC, defined as extension to the operator
 	for (int n=0;n<6;++n)
 	{
 		if (bounds[n]==2)
@@ -284,8 +282,6 @@ int openEMS::SetupFDTD(const char* file)
 
 	FDTD_Op->ShowStat();
 
-	FDTD_Op->ApplyMagneticBC(PMC);
-
 	cout << "Creation time for operator: " << difftime(OpDoneTime,startTime) << " s" << endl;
 
 	//create FDTD engine