diff --git a/mbus/mbus-protocol.c b/mbus/mbus-protocol.c
index 90e32b1..a2ef1b0 100644
--- a/mbus/mbus-protocol.c
+++ b/mbus/mbus-protocol.c
@@ -2096,7 +2096,7 @@ mbus_data_record_function(mbus_data_record *record)
     
     if (record)
     {
-        switch (record->drh.dib.dif & 0x30)
+        switch (record->drh.dib.dif & MBUS_DATA_RECORD_DIF_MASK_FUNCTION)
         {
             case 0x00:
                 snprintf(buff, sizeof(buff), "Instantaneous value");           
diff --git a/mbus/mbus-protocol.h b/mbus/mbus-protocol.h
index 6fdd3a6..d7b647e 100644
--- a/mbus/mbus-protocol.h
+++ b/mbus/mbus-protocol.h
@@ -405,8 +405,11 @@ typedef struct _mbus_data_secondary_address {
 #define MBUS_DATA_RECORD_DIF_MASK_MIN       0x10
 
 #define MBUS_DATA_RECORD_DIF_MASK_TYPE_INT32     0x04
+#define MBUS_DATA_RECORD_DIF_MASK_DATA           0x0F
+#define MBUS_DATA_RECORD_DIF_MASK_FUNCTION       0x30
 #define MBUS_DATA_RECORD_DIF_MASK_STORAGE_NO     0x40
 #define MBUS_DATA_RECORD_DIF_MASK_EXTENTION      0x80
+#define MBUS_DATA_RECORD_DIF_MASK_NON_DATA       0xF0
 
 //
 // GENERAL APPLICATION ERRORS