diff --git a/FDTD/operator.h b/FDTD/operator.h
index fd3e43a..aac6788 100644
--- a/FDTD/operator.h
+++ b/FDTD/operator.h
@@ -25,6 +25,7 @@
 
 class Operator_Extension;
 class Engine;
+class TiXmlElement;
 
 //! Abstract base-class for the FDTD-operator
 class Operator
@@ -44,6 +45,8 @@ public:
 
 	virtual int CalcECOperator();
 
+	virtual bool SetupExcitation(TiXmlElement* Excite, unsigned int maxTS) {return Exc->setupExcitation(Excite,maxTS);};
+
 	inline virtual FDTD_FLOAT& GetVV( unsigned int n, unsigned int x, unsigned int y, unsigned int z ) const { return vv[n][x][y][z]; }
 	inline virtual FDTD_FLOAT& GetVI( unsigned int n, unsigned int x, unsigned int y, unsigned int z ) const { return vi[n][x][y][z]; }
 
diff --git a/openems.cpp b/openems.cpp
index 23e8366..aa41423 100644
--- a/openems.cpp
+++ b/openems.cpp
@@ -351,7 +351,7 @@ int openEMS::SetupFDTD(const char* file)
 	if ((maxTime_TS>0) && (maxTime_TS<NrTS))
 		NrTS = maxTime_TS;
 
-	if (!FDTD_Op->Exc->setupExcitation( FDTD_Opts->FirstChildElement("Excitation"), NrTS ))
+	if (!FDTD_Op->SetupExcitation( FDTD_Opts->FirstChildElement("Excitation"), NrTS ))
 		exit(2);
 
 	if (DebugMat)