diff --git a/examples/FDTD_examples.cpp b/examples/FDTD_examples.cpp
index e73c035..57fd17c 100644
--- a/examples/FDTD_examples.cpp
+++ b/examples/FDTD_examples.cpp
@@ -597,3 +597,157 @@ void BuildCoaxial_Cartesian(const char* filename)
 	doc.SaveFile();
 }
 
+void BuildHelix(const char* filename)
+{
+	int maxIter = 10000;
+	double f0=0.15e9;
+	double fc=0.15e9;
+	int Excit_Type=0;
+	int bounds[] = {1,1,1,1,0,0};
+
+	cerr << "Create Helix Geometry..." << endl;
+	ContinuousStructure CSX;
+
+	double width = 800;
+	double length = 800;
+	double delta[] = {5,5,5};
+
+	//MSL
+	CSPropMaterial* copper = new CSPropMaterial(CSX.GetParameterSet());
+	copper->SetKappa(56e6);
+	copper->SetName("copper");
+	CSX.AddProperty(copper);
+
+	CSPrimUserDefined* helix = new CSPrimUserDefined(CSX.GetParameterSet(),copper);
+	helix->SetCoordSystem(CSPrimUserDefined::CYLINDER_SYSTEM);
+	helix->SetFunction("(r<110)&(r>90)&(sqrt(pow(x-r*cos(2*pi*z/100),2)+pow(y-r*sin(2*pi*z/100),2))<20)&(z>200)&(z<600)");
+	CSX.AddPrimitive(helix);
+	CSPrimCylinder* cyl = new CSPrimCylinder(CSX.GetParameterSet(),copper);
+	cyl->SetRadius(10);
+	cyl->SetCoord(0,100.0);cyl->SetCoord(1,310.0);
+	cyl->SetCoord(2,0.0);cyl->SetCoord(3,0.0);
+	cyl->SetCoord(4,200.0);cyl->SetCoord(5,200.0);
+	CSX.AddPrimitive(cyl);
+	cyl = new CSPrimCylinder(CSX.GetParameterSet(),copper);
+	cyl->SetRadius(10);
+	cyl->SetCoord(0,100.0);cyl->SetCoord(1,310.0);
+	cyl->SetCoord(2,0.0);cyl->SetCoord(3,0.0);
+	cyl->SetCoord(4,600.0);cyl->SetCoord(5,600.0);
+	CSX.AddPrimitive(cyl);
+
+	CSPropElectrode* elec = new CSPropElectrode(CSX.GetParameterSet());
+	elec->SetExcitation(1.0,2);
+	elec->SetExcitType(1);
+//	elec->SetDelay(2.0e-9);
+	CSX.AddProperty(elec);
+	cyl = new CSPrimCylinder(CSX.GetParameterSet(),elec);
+	cyl->SetRadius(10);
+	cyl->SetCoord(0,300.0);cyl->SetCoord(1,300.0);
+	cyl->SetCoord(2,0.0);cyl->SetCoord(3,0.0);
+	cyl->SetCoord(4,200.0);cyl->SetCoord(5,600.0);
+	CSX.AddPrimitive(cyl);
+
+	CSPropDumpBox* Edump = NULL;
+	//E-field dump xz
+	Edump = new CSPropDumpBox(CSX.GetParameterSet());
+	Edump->SetDumpType(0);
+	Edump->SetName("Et_xz_");
+	CSX.AddProperty(Edump);
+	CSPrimBox* box = new CSPrimBox(CSX.GetParameterSet(),Edump);
+	box->SetCoord(0,width/-2.0);box->SetCoord(1,width/2.0);
+	box->SetCoord(2,0.0);box->SetCoord(3,0.0);
+	box->SetCoord(4,-50.0);box->SetCoord(5,length);
+	CSX.AddPrimitive(box);
+//
+//	//E-field dump xy
+//	Edump = new CSPropDumpBox(CSX.GetParameterSet());
+//	Edump->SetDumpType(0);
+//	Edump->SetName("Et_xy_");
+//	CSX.AddProperty(Edump);
+//	box = new CSPrimBox(CSX.GetParameterSet(),Edump);
+//	box->SetCoord(0,width/-2.0);box->SetCoord(1,width/2.0);
+//	box->SetCoord(2,0.0);box->SetCoord(3,height);
+//	box->SetCoord(4,0.0);box->SetCoord(5,0.0);
+//	CSX.AddPrimitive(box);
+
+//	//E-field dump 3D
+//	Edump = new CSPropDumpBox(CSX.GetParameterSet());
+//	Edump->SetDumpType(0);
+//	Edump->SetDumpMode(2); //cell interpolated dump
+//	Edump->SetName("Et_");
+//	CSX.AddProperty(Edump);
+//	box = new CSPrimBox(CSX.GetParameterSet(),Edump);
+//	box->SetCoord(0,MSL_width*-1.5);box->SetCoord(1,MSL_width*1.5);
+//	box->SetCoord(2,0.0);box->SetCoord(3,MSL_height*1.5);
+//	box->SetCoord(4,length/-2.0);box->SetCoord(5,length/2.0);
+//	CSX.AddPrimitive(box);
+//
+	//voltage calc
+	CSPropProbeBox* volt = new CSPropProbeBox(CSX.GetParameterSet());
+	volt->SetProbeType(0);
+	volt->SetName("u1");
+	CSX.AddProperty(volt);
+	box = new CSPrimBox(CSX.GetParameterSet(),volt);
+	box->SetCoord(0,300.0);box->SetCoord(1,300.0);
+	box->SetCoord(2,0.0);box->SetCoord(3,0.0);
+	box->SetCoord(4,200.0);box->SetCoord(5,600.0);
+	CSX.AddPrimitive(box);
+
+	//current calc
+	CSPropProbeBox* curr = new CSPropProbeBox(CSX.GetParameterSet());
+	curr->SetProbeType(1);
+	curr->SetName("i1");
+	CSX.AddProperty(curr);
+	box = new CSPrimBox(CSX.GetParameterSet(),curr);
+	box->SetCoord(0,200.0);box->SetCoord(1,200.0);
+	box->SetCoord(2,-50.0);box->SetCoord(3,50.0);
+	box->SetCoord(4,150.0);box->SetCoord(5,250.0);
+	CSX.AddPrimitive(box);
+
+	CSRectGrid* grid = CSX.GetGrid();
+
+	for (double n=width/-2.0;n<=width/2;n+=delta[0])
+		grid->AddDiscLine(0,n);
+	for (double n=width/-2.0;n<=width/2;n+=delta[0])
+		grid->AddDiscLine(1,n);
+	for (double n=-50;n<=length;n+=delta[2])
+		grid->AddDiscLine(2,n);
+
+	grid->SetDeltaUnit(1e-3);
+
+	//*************** Create XML file **********************
+	TiXmlDocument doc(filename);
+	doc.InsertEndChild(TiXmlDeclaration("1.0","ISO-8859-1","yes"));
+
+	TiXmlElement openEMS("openEMS");
+
+	TiXmlElement FDTD_Opts("FDTD");
+	FDTD_Opts.SetAttribute("NumberOfTimesteps",maxIter);
+
+	TiXmlElement Excite("Excitation");
+	Excite.SetAttribute("Type",Excit_Type);
+	Excite.SetAttribute("f0",f0);
+	Excite.SetAttribute("fc",fc);
+	FDTD_Opts.InsertEndChild(Excite);
+
+	TiXmlElement BC("BoundaryCond");
+	BC.SetAttribute("xmin",bounds[0]);
+	BC.SetAttribute("xmax",bounds[1]);
+	BC.SetAttribute("ymin",bounds[2]);
+	BC.SetAttribute("ymax",bounds[3]);
+	BC.SetAttribute("zmin",bounds[4]);
+	BC.SetAttribute("zmax",bounds[5]);
+	FDTD_Opts.InsertEndChild(BC);
+
+	openEMS.InsertEndChild(FDTD_Opts);
+
+	if (CSX.Write2XML(&openEMS,true)==false)
+	{
+		cerr << "writing failed" << endl;
+		exit(-1);
+	}
+
+	doc.InsertEndChild(openEMS);
+
+	doc.SaveFile();
+}
diff --git a/examples/FDTD_examples.h b/examples/FDTD_examples.h
index b098c86..7c5d200 100644
--- a/examples/FDTD_examples.h
+++ b/examples/FDTD_examples.h
@@ -29,5 +29,6 @@ void BuildMSL(const char* filename);
 
 void BuildCoaxial_Cartesian(const char* filename);
 
+void BuildHelix(const char* filename);
 
 #endif // FDTD_EXAMPLES_H
diff --git a/examples/Helix.xml b/examples/Helix.xml
new file mode 100644
index 0000000..92f725e
--- /dev/null
+++ b/examples/Helix.xml
@@ -0,0 +1,78 @@
+<?xml version="1.0" encoding="ISO-8859-1" standalone="yes" ?>
+<openEMS>
+    <FDTD NumberOfTimesteps="10000">
+        <Excitation Type="0" f0="150000000" fc="150000000" />
+        <BoundaryCond xmin="1" xmax="1" ymin="1" ymax="1" zmin="0" zmax="0" />
+    </FDTD>
+    <ContinuousStructure>
+        <RectilinearGrid DeltaUnit="0.001000">
+            <XLines Qty="161">-400,-395,-390,-385,-380,-375,-370,-365,-360,-355,-350,-345,-340,-335,-330,-325,-320,-315,-310,-305,-300,-295,-290,-285,-280,-275,-270,-265,-260,-255,-250,-245,-240,-235,-230,-225,-220,-215,-210,-205,-200,-195,-190,-185,-180,-175,-170,-165,-160,-155,-150,-145,-140,-135,-130,-125,-120,-115,-110,-105,-100,-95,-90,-85,-80,-75,-70,-65,-60,-55,-50,-45,-40,-35,-30,-25,-20,-15,-10,-5,0,5,10,15,20,25,30,35,40,45,50,55,60,65,70,75,80,85,90,95,100,105,110,115,120,125,130,135,140,145,150,155,160,165,170,175,180,185,190,195,200,205,210,215,220,225,230,235,240,245,250,255,260,265,270,275,280,285,290,295,300,305,310,315,320,325,330,335,340,345,350,355,360,365,370,375,380,385,390,395,400</XLines>
+            <YLines Qty="161">-400,-395,-390,-385,-380,-375,-370,-365,-360,-355,-350,-345,-340,-335,-330,-325,-320,-315,-310,-305,-300,-295,-290,-285,-280,-275,-270,-265,-260,-255,-250,-245,-240,-235,-230,-225,-220,-215,-210,-205,-200,-195,-190,-185,-180,-175,-170,-165,-160,-155,-150,-145,-140,-135,-130,-125,-120,-115,-110,-105,-100,-95,-90,-85,-80,-75,-70,-65,-60,-55,-50,-45,-40,-35,-30,-25,-20,-15,-10,-5,0,5,10,15,20,25,30,35,40,45,50,55,60,65,70,75,80,85,90,95,100,105,110,115,120,125,130,135,140,145,150,155,160,165,170,175,180,185,190,195,200,205,210,215,220,225,230,235,240,245,250,255,260,265,270,275,280,285,290,295,300,305,310,315,320,325,330,335,340,345,350,355,360,365,370,375,380,385,390,395,400</YLines>
+            <ZLines Qty="171">-50,-45,-40,-35,-30,-25,-20,-15,-10,-5,0,5,10,15,20,25,30,35,40,45,50,55,60,65,70,75,80,85,90,95,100,105,110,115,120,125,130,135,140,145,150,155,160,165,170,175,180,185,190,195,200,205,210,215,220,225,230,235,240,245,250,255,260,265,270,275,280,285,290,295,300,305,310,315,320,325,330,335,340,345,350,355,360,365,370,375,380,385,390,395,400,405,410,415,420,425,430,435,440,445,450,455,460,465,470,475,480,485,490,495,500,505,510,515,520,525,530,535,540,545,550,555,560,565,570,575,580,585,590,595,600,605,610,615,620,625,630,635,640,645,650,655,660,665,670,675,680,685,690,695,700,705,710,715,720,725,730,735,740,745,750,755,760,765,770,775,780,785,790,795,800</ZLines>
+        </RectilinearGrid>
+        <ParameterSet />
+        <Properties>
+            <Material ID="0" Name="copper" Isotropy="1">
+                <FillColor R="33" G="61" B="220" a="255" />
+                <EdgeColor R="33" G="61" B="220" a="255" />
+                <Property Epsilon="1.000000e+00" Mue="1.000000e+00" Kappa="5.600000e+07" Sigma="0.000000e+00" />
+                <PropertyY Epsilon="1.000000e+00" Mue="1.000000e+00" Kappa="0.000000e+00" Sigma="0.000000e+00" />
+                <PropertyZ Epsilon="1.000000e+00" Mue="1.000000e+00" Kappa="0.000000e+00" Sigma="0.000000e+00" />
+                <WeightX Epsilon="1.000000e+00" Mue="1.000000e+00" Kappa="1.000000e+00" Sigma="1.000000e+00" />
+                <WeightY Epsilon="1.000000e+00" Mue="1.000000e+00" Kappa="1.000000e+00" Sigma="1.000000e+00" />
+                <WeightZ Epsilon="1.000000e+00" Mue="1.000000e+00" Kappa="1.000000e+00" Sigma="1.000000e+00" />
+            </Material>
+            <Electrode ID="1" Name="" Number="0" Delay="0.000000e+00">
+                <FillColor R="135" G="112" B="233" a="255" />
+                <EdgeColor R="135" G="112" B="233" a="255" />
+                <Excitation Type="1" Excit_X="0.000000e+00" Excit_Y="0.000000e+00" Excit_Z="1.000000e+00" />
+                <Weight X="1.000000e+00" Y="1.000000e+00" Z="1.000000e+00" />
+            </Electrode>
+            <DumpBox ID="2" Name="Et_xz_" GlobalSetting="1" DumpType="0" DumpMode="0">
+                <FillColor R="62" G="161" B="65" a="255" />
+                <EdgeColor R="62" G="161" B="65" a="255" />
+                <ScalarDump DumpPhi="1" DumpDivE="0" DumpDivD="0" DumpDivP="0" DumpFieldW="0" DumpChargeW="0" />
+                <VectorDump DumpEField="0" DumpDField="0" DumpPField="0" />
+                <SubGridDump SubGridDump="0" SimpleDump="0" SubGridLevel="-1" />
+            </DumpBox>
+            <ProbeBox ID="3" Name="u1" Number="0" Type="0">
+                <FillColor R="225" G="252" B="103" a="255" />
+                <EdgeColor R="225" G="252" B="103" a="255" />
+            </ProbeBox>
+            <ProbeBox ID="4" Name="i1" Number="0" Type="1">
+                <FillColor R="62" G="1" B="126" a="255" />
+                <EdgeColor R="62" G="1" B="126" a="255" />
+            </ProbeBox>
+        </Properties>
+        <Primitives>
+            <UserDefined ID="0" PropertyID="0" Priority="0" CoordSystem="1">
+                <CoordShift X="0.000000e+00" Y="0.000000e+00" Z="0.000000e+00" />
+                <Function>(r&lt;110)&amp;(r&gt;90)&amp;(sqrt(pow(x-r*cos(2*pi*z/100),2)+pow(y-r*sin(2*pi*z/100),2))&lt;20)&amp;(z&gt;200)&amp;(z&lt;600)</Function>
+            </UserDefined>
+            <Cylinder ID="1" PropertyID="0" Priority="0" Radius="1.000000e+01">
+                <P0 X="1.000000e+02" Y="0.000000e+00" Z="2.000000e+02" />
+                <P1 X="3.100000e+02" Y="0.000000e+00" Z="2.000000e+02" />
+            </Cylinder>
+            <Cylinder ID="2" PropertyID="0" Priority="0" Radius="1.000000e+01">
+                <P0 X="1.000000e+02" Y="0.000000e+00" Z="6.000000e+02" />
+                <P1 X="3.100000e+02" Y="0.000000e+00" Z="6.000000e+02" />
+            </Cylinder>
+            <Cylinder ID="3" PropertyID="1" Priority="0" Radius="1.000000e+01">
+                <P0 X="3.000000e+02" Y="0.000000e+00" Z="2.000000e+02" />
+                <P1 X="3.000000e+02" Y="0.000000e+00" Z="6.000000e+02" />
+            </Cylinder>
+            <Box ID="4" PropertyID="2" Priority="0">
+                <P1 X="-4.000000e+02" Y="0.000000e+00" Z="-5.000000e+01" />
+                <P2 X="4.000000e+02" Y="0.000000e+00" Z="8.000000e+02" />
+            </Box>
+            <Box ID="5" PropertyID="3" Priority="0">
+                <P1 X="3.000000e+02" Y="0.000000e+00" Z="2.000000e+02" />
+                <P2 X="3.000000e+02" Y="0.000000e+00" Z="6.000000e+02" />
+            </Box>
+            <Box ID="6" PropertyID="4" Priority="0">
+                <P1 X="2.000000e+02" Y="-5.000000e+01" Z="1.500000e+02" />
+                <P2 X="2.000000e+02" Y="5.000000e+01" Z="2.500000e+02" />
+            </Box>
+        </Primitives>
+    </ContinuousStructure>
+</openEMS>
diff --git a/main.cpp b/main.cpp
index 1a7437a..cbfb569 100644
--- a/main.cpp
+++ b/main.cpp
@@ -23,7 +23,7 @@
 
 #include "examples/FDTD_examples.h"
 
-#define STANDALONE
+//#define STANDALONE
 
 using namespace std;
 
@@ -73,11 +73,15 @@ int main(int argc, char *argv[])
 	const char* fileCoax="../examples/Coax_Cart.xml";
 	BuildCoaxial_Cartesian(fileCoax);
 
-	const char* file=fileMSL;
+	const char* fileHelix="../examples/Helix.xml";
+	BuildHelix(fileHelix);
+
+	const char* file=fileHelix;
 
 //	cerr << CSX.ReadFromXML("examples/PlaneWave.xml") << endl;
 #endif
 
+	FDTD.DebugMaterial();
 	int EC = FDTD.SetupFDTD(file);
 	if (EC) return EC;
 	FDTD.RunFDTD();