diff --git a/Aux/EventBuilder.cpp b/Aux/EventBuilder.cpp
index 803f92c..41ff87c 100644
--- a/Aux/EventBuilder.cpp
+++ b/Aux/EventBuilder.cpp
@@ -73,6 +73,8 @@ int main(int argc, char **argv) {
     outFileFullName = outFileName + ".bin";
   }
 
+  uint16_t header = 0; // for caen bin
+
   printf("-------> Out file name : %s \n", outFileFullName.Data());
   printf("========================================= Number of Files : %d \n", nFile);
   for( int i = 0; i < nFile; i++) printf("%2d | %s \n", i, inFileName[i].Data());
@@ -321,8 +323,17 @@ int main(int argc, char **argv) {
       // tree->Write();
     }else{
       if( caen ) {
+        
+        if( header == 0 ){
+          header = 0xCAE1; // default to have the energy only
+          if( events[0].energy2 > 0 ) header += 0x4;
+          if( events[0].traceLength > 0 && traceOn ) header += 0x8;
+          size_t dummy = fwrite(&header, 2, 1, caen);
+          if( dummy != 1 ) printf("file write error.\n");
+        }
+
         for( size_t gg = 0; gg < events.size(); gg++ ){
-          events[gg].WriteHitsToCAENBinary(caen, traceOn);
+          events[gg].WriteHitsToCAENBinary(caen, header);
         }
       }
     }
diff --git a/Aux/Makefile b/Aux/Makefile
index 9b731a9..8d51ec9 100644
--- a/Aux/Makefile
+++ b/Aux/Makefile
@@ -5,8 +5,8 @@
 
 CC	=	g++
 
-#COPTS	=	-fPIC -DLINUX -O2 -std=c++17 -lpthread
-COPTS	=	-fPIC -DLINUX -g -O0 -Wall -std=c++17 -lpthread
+COPTS	=	-fPIC -DLINUX -O2 -std=c++17 -lpthread
+# COPTS	=	-fPIC -DLINUX -g -O0 -Wall -std=c++17 -lpthread
 
 CAENLIBS	=	-lCAENDigitizer -lCAENVME
 
diff --git a/Hit.h b/Hit.h
index 6d8950a..2154f9e 100644
--- a/Hit.h
+++ b/Hit.h
@@ -48,19 +48,17 @@ public:
   }  
 
 
-  void WriteHitsToCAENBinary(FILE * file, bool withTrace){
+  void WriteHitsToCAENBinary(FILE * file, uint32_t header){
     if( file == nullptr ) return;
 
-    uint16_t header = 0xCAE1; // default to have the energy only
     uint32_t flag = 0;
     uint8_t  waveFormCode = 1; // input
 
+    // uint16_t header = 0xCAE1; // default to have the energy only
+    // if( energy2 > 0 ) header += 0x4;
+    // if( traceLength > 0 && withTrace ) header += 0x8;
+
     size_t dummy;
-
-    if( energy2 > 0 ) header += 0x4;
-    if( traceLength > 0 && withTrace ) header += 0x8;
-
-    dummy = fwrite(&header, 2, 1, file);
     dummy = fwrite(&sn, 2, 1, file);
     dummy = fwrite(&ch, 2, 1, file);
 
@@ -69,11 +67,11 @@ public:
 
     dummy = fwrite(&energy, 2, 1, file);
 
-    if( energy2 > 0 ) dummy = fwrite(&energy2, 2, 1, file);
+    if( (header & 0x4) ) dummy = fwrite(&energy2, 2, 1, file);
 
     dummy = fwrite(&flag, 4, 1, file);
 
-    if( traceLength > 0 && withTrace ){
+    if( traceLength > 0 && (header & 0x8) ){
       dummy = fwrite(&waveFormCode, 1, 1, file);
       dummy = fwrite(&traceLength, 4, 1, file);
       for( int j = 0; j < traceLength; j++ ){