diff --git a/.gitignore b/.gitignore
index 7527a69..bd788c2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -20,6 +20,7 @@ DAQLock.dat
 DumpFSU2ROOT
 SettingsExplorer
 AggSeparator
+FSU2CAEN
 
 data
 
diff --git a/Aux/FSU2CAEN.cpp b/Aux/FSU2CAEN.cpp
new file mode 100644
index 0000000..a802b20
--- /dev/null
+++ b/Aux/FSU2CAEN.cpp
@@ -0,0 +1,236 @@
+#include "fsuReader.h"
+
+struct FileInfo{
+  std::string fileName;
+  int fileevID;
+  unsigned long hitCount;
+};
+
+const unsigned short header = 0xCAE1;
+const unsigned int flags = 0;
+
+#define minNARG  4
+
+//^#############################################################
+//^#############################################################
+int main(int argc, char **argv) {
+  
+  printf("=========================================\n");
+  printf("===      *.fsu to CoMPASS bin         ===\n");
+  printf("===      no trace, no flags           ===\n");
+  printf("=========================================\n");  
+  if (argc < minNARG)    {
+    printf("Incorrect number of arguments:\n");
+    printf("%s [tar] [batchSize] [inFile1] [inFile2] .... \n", argv[0]);
+    printf("           tar : output tar, 0 = no, 1 = yes \n");   
+    printf("     batchSize : the size of hit in a batch \n");   
+    printf("\n");
+    printf(" Example: %s 100000 '\\ls -1 *001*.fsu'\n", argv[0]);
+    printf("\n\n");
+
+    return 1;
+  }
+  unsigned int debug = false;
+
+  uInt runStartTime = getTime_us();
+
+  ///============= read input
+  // long timeWindow = atoi(argv[1]);
+  // bool traceOn = atoi(argv[2]);
+  bool tarFlag = atoi(argv[1]);
+  unsigned int batchSize = atoi(argv[2]);
+  int nFile = argc - minNARG + 1;
+  std::string inFileName[nFile];
+  for( int i = 0 ; i < nFile ; i++){ inFileName[i] = argv[i+ minNARG - 1];}
+
+
+  std::string temp = inFileName[0];
+  size_t pos = temp.find('_');
+  pos = temp.find('_', pos + 1);
+  std::string outFile_prefix = temp.substr(0, pos);
+  std::string outFileName = outFile_prefix + ".BIN";
+
+  
+  printf("========================================= Number of Files : %d \n", nFile);
+  for( int i = 0; i < nFile; i++) printf("%2d | %s \n", i, inFileName[i].c_str());
+  printf("=========================================\n"); 
+  printf("  Include Trace = %s\n", "No");
+  printf("     Batch size = %d events/file\n", batchSize);
+  printf("  Out file name = %s \n", outFileName.c_str());
+  printf("  Is tar output = %s \n", tarFlag ? "Yes" : "No");
+  printf("========================================= Grouping files\n");  
+
+  std::vector<std::vector<FileInfo>> fileGroupList; // fileName and evID = SN * 1000 + index
+  std::vector<FileInfo> fileList;
+
+  unsigned long long int totalHitCount = 0;
+
+  FSUReader * readerA = new FSUReader(inFileName[0], 1, 1);
+  readerA->ScanNumBlock(0,0);
+  FileInfo fileInfo = {inFileName[0], readerA->GetSN() * 1000 +  readerA->GetFileOrder(), readerA->GetHitCount()};
+  fileList.push_back(fileInfo);
+  totalHitCount += readerA->GetHitCount();
+
+  for( int i = 1; i < nFile; i++){
+    FSUReader * readerB = new FSUReader(inFileName[i], 1, 1);
+    readerB->ScanNumBlock(0,0);
+    totalHitCount += readerB->GetHitCount();
+    fileInfo = {inFileName[i], readerB->GetSN() * 1000 +  readerB->GetFileOrder(), readerB->GetHitCount()};
+    
+    if( readerA->GetSN() == readerB->GetSN() ){
+      fileList.push_back(fileInfo);
+    }else{
+      fileGroupList.push_back(fileList);
+      fileList.clear();
+      fileList.push_back(fileInfo);
+    }
+  
+    delete readerA;
+    readerA = readerB;
+  }
+  fileGroupList.push_back(fileList);
+  delete readerA;
+
+  printf("======================= total Hit Count : %llu\n", totalHitCount);
+
+  for( size_t i = 0; i < fileGroupList.size(); i++){
+    printf("group ----- %ld \n", i);
+
+    //sort by evID
+    std::sort(fileGroupList[i].begin(), fileGroupList[i].end(), [](const FileInfo & a, const FileInfo & b) {
+      return a.fileevID < b.fileevID;
+    });
+
+    for( size_t j = 0; j < fileGroupList[i].size(); j++){
+      printf("%3ld | %8d | %9lu| %s \n", j, fileGroupList[i][j].fileevID, fileGroupList[i][j].hitCount, fileGroupList[i][j].fileName.c_str() );
+    }
+
+  }
+
+  //*======================================= Open files
+  printf("========================================= Open files & Build Events.\n"); 
+
+  const short nGroup = fileGroupList.size();
+  std::vector<Hit> hitList[nGroup];
+  
+  FSUReader ** reader = new FSUReader * [nGroup];
+  ulong evID[nGroup];
+  for( short i = 0; i < nGroup; i++){
+    std::vector<std::string> fList;
+    for( size_t j = 0; j < fileGroupList[i].size(); j++){
+      fList.push_back( fileGroupList[i][j].fileName );
+    }
+    reader[i] = new FSUReader(fList, 600, debug);
+    hitList[i] = reader[i]->ReadBatch(batchSize, debug );
+    reader[i]->PrintHitListInfo(&hitList[i], "hitList-" + std::to_string(reader[i]->GetSN()));
+    evID[i] = 0;
+    if( debug ) {
+
+      for( size_t p = 0; p < 10; p ++ ){
+        if( hitList[i].size() <= p ) break;
+        hitList[i][p].Print();
+      }
+
+    }
+  }
+
+  unsigned long long tStart = 0;
+  unsigned long long tEnd = 0;
+
+  unsigned long long t0 = -1;
+  short g0 = 0 ;
+  int nFileFinished = 0;
+  unsigned long long hitProcessed = 0;
+
+  FILE * outFile = fopen(outFileName.c_str(), "wb");
+
+  do{
+
+    // find the earlist time
+    t0 = -1;
+    for( short i = 0; i < nGroup; i++){
+
+      if( hitList[i].size() == 0 ) continue;
+
+      //chekc if reached the end of hitList
+      if( evID[i] >= hitList[i].size() ) {
+        hitList[i] = reader[i]->ReadBatch(batchSize, debug + 1);
+        if( debug ) reader[i]->PrintHitListInfo( &hitList[i], "hitList-" + std::to_string(i));
+        evID[i] = 0;
+        if( hitList[i].size() == 0 ) continue;
+      }
+
+      if( hitList[i][evID[i]].timestamp < t0 ) {
+        t0 = hitList[i][evID[i]].timestamp;
+        g0 = i;
+      }
+      
+    }
+
+    fwrite(&(header), 2, 1, outFile);
+    fwrite(&(hitList[g0][evID[g0]].sn), 2, 1, outFile);
+    fwrite(&(hitList[g0][evID[g0]].ch), 2, 1, outFile);
+    fwrite(&(hitList[g0][evID[g0]].timestamp), 8, 1, outFile);
+    fwrite(&(hitList[g0][evID[g0]].energy), 2, 1, outFile);
+    fwrite(&(flags), 4, 1, outFile);
+
+    evID[g0]++;
+    if( hitProcessed == 0) tStart = hitList[g0][evID[g0]].timestamp;
+    hitProcessed ++;
+    if( hitProcessed % 10000 == 0 ) printf("hit Porcessed %llu/%llu hit....%.2f%%\n\033[A\r", hitProcessed, totalHitCount, hitProcessed*100./totalHitCount);
+
+    if( hitProcessed == totalHitCount -1 ) tEnd = hitList[g0][evID[g0]].timestamp;
+
+    //*=============
+    nFileFinished = 0;
+    for( int i = 0 ; i < nGroup; i++) {
+      if( hitList[i].size() == 0 ) {
+        nFileFinished ++;
+        continue;
+      }else{
+        if( evID[i] >= hitList[i].size( )) {
+          hitList[i] = reader[i]->ReadBatch(batchSize, debug);
+          evID[i] = 0;
+          if( hitList[i].size() == 0 ) nFileFinished ++;
+        }
+      }
+    }
+    if( debug > 1 ) printf("========== nFileFinished : %d\n", nFileFinished);
+
+  }while( nFileFinished < nGroup);
+
+  uInt runEndTime = getTime_us();
+  double runTime = (runEndTime - runStartTime) * 1e-6;
+  printf("========================================= finished.\n");
+  printf(" event building time = %.2f sec = %.2f min\n", runTime, runTime/60.);
+  printf("           total hit = %llu \n", hitProcessed);
+  double tDuration_sec = (tEnd - tStart) * 1e-9;
+  printf("     first timestamp = %20llu ns\n", tStart);
+  printf("      last timestamp = %20llu ns\n", tEnd);
+  printf(" total data duration = %.2f sec = %.2f min\n", tDuration_sec, tDuration_sec/60.);
+  printf("==============> saved to %s \n", outFileName.c_str());
+  
+  for( int i = 0; i < nGroup; i++) delete reader[i];
+  delete [] reader;
+
+  if( tarFlag ){
+    std::string tarFileName = outFile_prefix + ".tar";
+
+    std::string command = "tar -cvf " + tarFileName + " " + outFileName;
+    int result = std::system(command.c_str());
+
+    if (result == 0) {
+      printf("Archive created successfully: %s\n", tarFileName.c_str());
+      std::system(("rm -f " + outFileName).c_str());
+      printf("Remove %s.\n", outFileName.c_str());
+    } else {
+      printf("Error creating archive\n");
+    }
+  }
+  
+  printf("============================================== end of program\n");
+
+  return 0;
+
+}
+
diff --git a/Aux/Makefile b/Aux/Makefile
index 27f7e4d..9b731a9 100644
--- a/Aux/Makefile
+++ b/Aux/Makefile
@@ -14,7 +14,7 @@ ROOTLIBS = `root-config --cflags --glibs`
 
 OBJS = ClassDigitizer.o MultiBuilder.o ClassInfluxDB.o
 
-ALL = test EventBuilder DataReader DumpFSU2ROOT SettingsExplorer 
+ALL = test EventBuilder DataReader DumpFSU2ROOT SettingsExplorer FSU2CAEN
 
 #########################################################################
 
@@ -44,17 +44,13 @@ DataReader : DataReaderScript.cpp ../ClassData.h MultiBuilder.o
 		@echo "--------- making DataReader"
 		$(CC) $(COPTS) -o DataReader DataReaderScript.cpp ../ClassData.h MultiBuilder.o
 
-# EventBuilder_old : EventBuilder_old.cpp ../ClassData.h MultiBuilder.o fsuReader.h
-# 		@echo "--------- making EventBuilder"
-# 		$(CC) $(COPTS) -o EventBuilder_old EventBuilder_old.cpp MultiBuilder.o $(ROOTLIBS) 
-
 EventBuilder : EventBuilder.cpp ../ClassData.h fsuReader.h ../Hit.h
 		@echo "--------- making EventBuilder"
 		$(CC) $(COPTS) -o EventBuilder EventBuilder.cpp $(ROOTLIBS) 
 
-# EventBuilderNoTrace : EventBuilderNoTrace.cpp ../ClassData.h fsuReader.h ../Hit.h 
-# 		@echo "--------- making EventBuilderNoTrace"
-# 		$(CC) $(COPTS) -o EventBuilderNoTrace EventBuilderNoTrace.cpp  $(ROOTLIBS) 
+FSU2CAEN : FSU2CAEN.cpp ../ClassData.h fsuReader.h ../Hit.h
+		@echo "--------- making FSU2CAEN"
+		$(CC) $(COPTS) -o FSU2CAEN FSU2CAEN.cpp 
 
 DumpFSU2ROOT : DumpFSU2ROOT.cpp ../ClassData.h MultiBuilder.o
 		@echo "--------- making DumpFSU2ROOT"