diff --git a/EC-GN-JA-PCF-IN/src/main/resources/qst-gyrotron-fast-controller/Configurations/src/thread2/sdn.marte b/EC-GN-JA-PCF-IN/src/main/resources/qst-gyrotron-fast-controller/Configurations/src/thread2/sdn.marte
index 37ea1ad..9a5b30c 100644
--- a/EC-GN-JA-PCF-IN/src/main/resources/qst-gyrotron-fast-controller/Configurations/src/thread2/sdn.marte
+++ b/EC-GN-JA-PCF-IN/src/main/resources/qst-gyrotron-fast-controller/Configurations/src/thread2/sdn.marte
@@ -72,7 +72,12 @@
       //! unused: SDN header not used
       Header = {
         Type = uint8
-        NumberOfElements = 52
+        NumberOfElements = 48
+      }
+      //! unused: not used anywhere
+      Dummy = {
+        Type = uint8
+        NumberOfElements = 4
       }
       ESDNTime = {
         Type = uint32