Index: /trunk/MagicSoft/Simulation/Detector/include-MTrigger/MTrigger.cxx
===================================================================
--- /trunk/MagicSoft/Simulation/Detector/include-MTrigger/MTrigger.cxx	(revision 1198)
+++ /trunk/MagicSoft/Simulation/Detector/include-MTrigger/MTrigger.cxx	(revision 1199)
@@ -852,5 +852,5 @@
 }
 
-void MTrigger::ElecNoise() {
+void MTrigger::ElecNoise(Float_t factor) {
   // ============================================================
   //
@@ -860,17 +860,31 @@
   Float_t rausch ; 
 
-  rausch = RESPONSE_AMPLITUDE * 0.3 ; 
+  rausch = RESPONSE_AMPLITUDE * factor ; 
  
   for ( Int_t i=0 ; i < TRIGGER_PIXELS; i++  ) {
-    if ( used [i] == TRUE ) {
-       
+      //
+      //  but at the beginning we must check if this pixel is
+      //  hitted the first time
+      //
+      
+      if ( used[i] == FALSE ) {
+	  used [i] = TRUE ; 
+	  
+	  for (Int_t ii=0; ii < TRIGGER_TIME_SLICES; ii++ ) {
+	      a_sig[i][ii] = 0. ; 
+	      d_sig[i][ii] = 0. ; 
+	  }
+      }
+      //      
+      //  Then the noise is introduced for each time slice
+      //
       for ( Int_t ii=1 ; ii<TRIGGER_TIME_SLICES; ii++ ) { 
-
-	a_sig [i][ii] +=  GenElec->Gaus(0., rausch  ) ; 
-
-      }
-    }
-  }
-}
+	  
+	  a_sig [i][ii] +=  GenElec->Gaus(0., rausch  ) ; 
+	  
+      }
+  }
+}
+
 void MTrigger::SetFwhm(Float_t fwhm){
   //===========================================================