diff --git a/ClassData.h b/ClassData.h
index db23353..0e0afd5 100644
--- a/ClassData.h
+++ b/ClassData.h
@@ -52,6 +52,7 @@ class Data{
 
     int GetLoopIndex(unsigned short ch) const {return LoopIndex[ch];}
     int GetDataIndex(unsigned short ch) const {return DataIndex[ch];}
+    long GetAbsDataIndex(unsigned short ch) const {return LoopIndex[ch] * dataSize + DataIndex[ch];}
 
     uShort GetDataSize() const {return dataSize;}
 
diff --git a/SingleSpectra.cpp b/SingleSpectra.cpp
index 1707e9f..962df10 100644
--- a/SingleSpectra.cpp
+++ b/SingleSpectra.cpp
@@ -252,7 +252,7 @@ void SingleSpectra::FillHistograms(){
   clock_gettime(CLOCK_REALTIME, &ta);
 
   std::vector<int> digiChList; // (digi*1000 + ch) 
-  std::vector<int> digiChLastIndex; // loop * dataSize + index; 
+  std::vector<long> digiChLastIndex; // loop * dataSize + index; 
   std::vector<int> digiChAvalibleData; 
   std::vector<bool> digiChFilled;
   std::vector<int> digiChFilledCount; 
@@ -260,10 +260,7 @@ void SingleSpectra::FillHistograms(){
 
   for( int ID = 0; ID < nDigi; ID++){
     for( int ch = 0; ch < digi[ID]->GetNumInputCh(); ch++){
-      int lastIndex = digi[ID]->GetData()->GetDataIndex(ch);
-      int loopIndex = digi[ID]->GetData()->GetLoopIndex(ch);
-
-      int temp1 = lastIndex + loopIndex * digi[ID]->GetData()->GetDataSize();
+      int temp1 = digi[ID]->GetData()->GetAbsDataIndex(ch); 
       int temp2 = lastFilledIndex[ID][ch];
 
       if( temp1 <= temp2 ) continue;
@@ -272,6 +269,9 @@ void SingleSpectra::FillHistograms(){
       digiChAvalibleData.push_back(temp1-temp2);
       digiChFilled.push_back(false);
       digiChFilledCount.push_back(0);
+
+      if( temp1 - temp2 > digi[ID]->GetData()->GetDataSize() ) lastFilledIndex[ID][ch] = temp1 - digi[ID]->GetData()->GetDataSize() ;
+
     }
   }
 
@@ -302,9 +302,6 @@ void SingleSpectra::FillHistograms(){
       // printf("Digi-%2d ch-%2d all filled | %zu\n", ID, ch, digiChList.size());
       continue;
     }
-    if( digiChLastIndex[randomValue] - lastFilledIndex[ID][ch] > digi[ID]->GetData()->GetDataSize() ) { //DefaultDataSize = 10k
-      lastFilledIndex[ID][ch] = digiChLastIndex[randomValue] -  digi[ID]->GetData()->GetDataSize() ;
-    }
 
     lastFilledIndex[ID][ch] ++;
     digiChFilledCount[randomValue]++;
diff --git a/analyzers/NeutronGamma.h b/analyzers/NeutronGamma.h
index 94b10cf..65996b0 100644
--- a/analyzers/NeutronGamma.h
+++ b/analyzers/NeutronGamma.h
@@ -74,8 +74,7 @@ private:
   QGroupBox * histBox;
   QGridLayout * histLayout;
 
-  int lastFilledIndex[MaxNDigitizer][MaxNChannels];
-  int loopFilledIndex[MaxNDigitizer][MaxNChannels];
+  int lastFilledIndex[MaxNDigitizer][MaxNChannels];// absolute data index = loop * dataSize + index
 
   bool fillHistograms;
 
@@ -178,7 +177,6 @@ inline void NeutronGamma::ClearInternalDataCount(){
   for( unsigned int i = 0; i < nDigi; i++){
     for( int ch = 0; ch < MaxRegChannel ; ch++) {
       lastFilledIndex[i][ch] = -1;
-      loopFilledIndex[i][ch] = 0;
     }
   }
 }
@@ -190,36 +188,25 @@ inline void NeutronGamma::UpdateHistograms(){
   int ID = cbDigi->currentData().toInt();
   int ch = cbCh->currentData().toInt();
 
-  int lastIndex = digi[ID]->GetData()->GetDataIndex(ch);
-  if( lastIndex < 0 ) return;
+  if( digi[ID]->GetData()->GetDataIndex(ch) < 0 ) return;
 
-  int loopIndex = digi[ID]->GetData()->GetLoopIndex(ch);
+  int dataAvalible = digi[ID]->GetData()->GetAbsDataIndex(ch) - lastFilledIndex[ID][ch];
 
-  int temp1 = lastIndex + loopIndex * digi[ID]->GetData()->GetDataSize();
-  int temp2 = lastFilledIndex[ID][ch] + loopFilledIndex[ID][ch] * digi[ID]->GetData()->GetDataSize() + 1;
-
-  if( temp1 - temp2 > digi[ID]->GetData()->GetDataSize() ) { //DefaultDataSize = 10k
-    temp2 = temp1 - digi[ID]->GetData()->GetDataSize();
-    lastFilledIndex[ID][ch] = lastIndex;
-    lastFilledIndex[ID][ch] = loopIndex - 1;
+  if( dataAvalible > digi[ID]->GetData()->GetDataSize() ) { //DefaultDataSize = 10k
+    lastFilledIndex[ID][ch] = digi[ID]->GetData()->GetAbsDataIndex(ch) - digi[ID]->GetData()->GetDataSize();
   }
 
-  for( int j = 0 ; j <= temp1 - temp2; j ++){
+  do{
     lastFilledIndex[ID][ch] ++;
-    if( lastFilledIndex[ID][ch] > digi[ID]->GetData()->GetDataSize() ) {
-      lastFilledIndex[ID][ch] = 0;
-      loopFilledIndex[ID][ch] ++;
-    }
 
     uShort data_long = digi[ID]->GetData()->GetEnergy(ch, lastFilledIndex[ID][ch]);
     uShort data_short = digi[ID]->GetData()->GetEnergy2(ch, lastFilledIndex[ID][ch]);
 
     // printf(" ch: %d, last fill idx : %d | %d \n", ch, lastFilledIndex[ID][ch], data);
-
     double psd = (data_long - data_short) *1.0 / data_long;
-
     hist2D->Fill(data_long, psd);
-  }
+
+  }while(lastFilledIndex[ID][ch] <= digi[ID]->GetData()->GetAbsDataIndex(ch));
 
   hist2D->UpdatePlot();