diff --git a/docs/Enedis-NOI-CPT_54E.pdf b/docs/Enedis-NOI-CPT_54E.pdf
new file mode 100644
index 0000000..47d3668
Binary files /dev/null and b/docs/Enedis-NOI-CPT_54E.pdf differ
diff --git a/tic.cpp b/tic.cpp
index ab33752..0162c1b 100644
--- a/tic.cpp
+++ b/tic.cpp
@@ -23,6 +23,9 @@ int nbActions;
 
 static struct GroupDetail processGroup(String group) {
   struct GroupDetail gd;
+  gd.globale = group;
+  unsigned char computedChecksum = calcCheckSum(group);
+
   int indexgrp = group.indexOf(HT);
   gd.name = group.substring(0, indexgrp);
 
@@ -32,15 +35,20 @@ static struct GroupDetail processGroup(String group) {
 
   group = group.substring(indexgrp + 1);
   indexgrp = group.indexOf(HT);
-  String key = group.substring(0, indexgrp);
-
-  group = group.substring(indexgrp + 1);
-  indexgrp = group.indexOf(HT);
+  String key = "";
   if (indexgrp != -1)  // some parameters may have hour recording.
   {
     gd.horodate = gd.value;
-    gd.value = key;
+    gd.value = group.substring(0, indexgrp);
+    group = group.substring(indexgrp + 1);
   }
+  //gd.checksum = group;
+  if (group[0]==computedChecksum) {
+    gd.checkok = true;
+  } else {
+    gd.checkok = false;
+  }
+
   return gd;
 }
 
@@ -114,19 +122,18 @@ static void processTrame(String &data) {
       while ((SelectedEtiquette[t] != gd.name) && (t < NB_ETIQUETTE)) {
         ++t;
       }
-      // If a match is found, update the corresponding TicValues entry
-      if (t < NB_ETIQUETTE) {
+      // If a match is found, update the corresponding TicValues entry if the group confirms the checksum
+      if (t < NB_ETIQUETTE)   {
         //If there is a value update
-        if (TicValues[t].value.compareTo(gd.value) != 0) {
+        if (TicValues[t].value.compareTo(gd.value) != 0 && gd.checkok){
           //There is some noise on instantaneous value, filter
           if (SelectedEtiquette[t] == "SINSTS" || SelectedEtiquette[t] == "SINSTS1" || SelectedEtiquette[t] == "SINSTS2" || SelectedEtiquette[t] == "SINSTS3") {
-            int oldval  = TicValues[t].value.toInt();
+            int oldval = TicValues[t].value.toInt();
             int newcal = (gd.value.toInt() + oldval) / 2;
-            if (newcal < oldval*0.92 || newcal > oldval*1.02){
-            gd.updated = true;
-            TicValues[t] = gd;
-            }
-            else {
+            if (newcal < oldval * 0.92 || newcal > oldval * 1.02) {
+              gd.updated = true;
+              TicValues[t] = gd;
+            } else {
               TicValues[t].value = String(newcal);
             }
           } else {
@@ -295,9 +302,11 @@ String ticValuesAsJson() {
 
       // Use snprintf to construct the JSON string efficiently
       snprintf(jres, sizeof(jres),
-               "\"%s\": \"%s\"",
+               "\"%s\": [\"%s\", \"%s\", \"%s\"]",
                SelectedEtiquette[i].c_str(),
-               TicValues[i].value.c_str());
+               TicValues[i].globale.c_str(),
+               TicValues[i].value.c_str(),
+               TicValues[i].checkok?"true":"false");
       response += jres;
     }
 
@@ -425,4 +434,47 @@ void readTicPort() {
       }
     }
   }
-}
\ No newline at end of file
+}
+
+// Function to calculate the checksum
+unsigned char calcCheckSum(const String &data) {
+  unsigned int sum = 0;
+
+  // Calculate the sum of ASCII values
+  for (size_t i = 0; i < data.length() - 1; ++i) {
+    sum += data[i];
+  }
+
+  // Truncate the sum to 6 bits
+  sum &= 0x3F;
+
+  // Add 0x20 to get the final checksum
+  unsigned char checksum = sum + 0x20;
+
+  return checksum;
+}
+
+unsigned char calcCheckSum2(GroupDetail *data) {
+  char c;
+  uint sum = 2 * HT;
+
+  if (data->name.length() && data->value.length()) {
+    for (char &c : data->name) {
+      if (c >= 0x20 && c <= 0x7E) {
+        sum += c;
+      } else {
+        return 0;
+      }
+    }
+
+    for (char &c : data->value) {
+      if (c >= 0x20 && c <= 0x7E) {
+        sum += c;
+      } else {
+        return 0;
+      }
+    }
+    return (sum & 0x3f) + 0x20;
+  }
+  return 0;
+}
diff --git a/tic.h b/tic.h
index 557afbd..c930010 100644
--- a/tic.h
+++ b/tic.h
@@ -13,6 +13,7 @@
 #define HTTP_PORT 80 //port
 
 // Définition des constantes pour les délimiteurs de trame TIC
+//Uniquement le mode standard est supporté
 //CF document ENEDIS
 #define STX 0x02             // Début de la trame : 0x02 (<STX>)
 #define ETX 0x03             // Fin de la trame : 0x03 (<ETX>) End Of Text
@@ -29,10 +30,12 @@
 
 // Structure pour stocker les détails d'un groupe TIC
 struct GroupDetail {
+  String globale;
   String name;      // Nom de l'étiquette
   String value;     // Valeur associée à l'étiquette
   String horodate;  // Horodatage de la valeur
   bool updated;
+  bool checkok; //status of checksum
 };
 
 // Structure pour les bits de statut du registre
@@ -163,4 +166,5 @@ String ticValuesAsJson();
 String ticBasicValuesAsJson();
 void mqttPublish(PubSubClient *mqttclient);
 void mqttForcePublish(PubSubClient *mqttclient); 
+unsigned char calcCheckSum(const String &data);//(GroupDetail *data);
 #endif
\ No newline at end of file