-# between nodes 200 and edge (578, 577), plane includes vector (1,1,1)
-segments.append( SMESH.PolySegment( 200, 0, SMESH.PointStruct(-1, -1, -1), 578, 577, SMESH.PointStruct(-1, -1, -1), smesh.MakeDirStruct(1,1,1) ))
+
+# between node 200 and edge (578, 577), plane includes vector (1,1,1)
+#segments.append( SMESH.PolySegment( 200, 0, SMESH.PointStruct(-1, -1, -1), 578, 577, SMESH.PointStruct(-1, -1, -1), smesh.MakeDirStruct(1,1,1) ))
+# nodes 578 and 577 are not always neighbour, so, use another approach
+
+# between node 200 and an edge, close to point (200, 90, 70), plane includes vector (1,1,1)
+elems = Mesh_1.FindElementsByPoint(200, 90, 70, SMESH.FACE)
+nodes = Mesh_1.GetElemNodes(elems[0])
+segments.append( SMESH.PolySegment( 200, 0, SMESH.PointStruct(-1, -1, -1), nodes[0], nodes[1], SMESH.PointStruct(-1, -1, -1), smesh.MakeDirStruct(1,1,1) ))