Index: TDDefs.h
===================================================================
diff -u -r2c1b884ffa2b9fafeea0025b8c4ac3f46bc2e8f0 -rc416b53b4723863a6016cf0bae9f466493b32c22
--- TDDefs.h	(.../TDDefs.h)	(revision 2c1b884ffa2b9fafeea0025b8c4ac3f46bc2e8f0)
+++ TDDefs.h	(.../TDDefs.h)	(revision c416b53b4723863a6016cf0bae9f466493b32c22)
@@ -882,6 +882,7 @@
 ///< Enumeration of tube set types.
 enum Tube_Set_Types
 {
+    TUBE_SET_TYPE_UNKNOWN = 0,                                          ///< Unknown tube set type
     TUBE_SET_TYPE_HD,                                                   ///< HD tubing set
     TUBE_SET_TYPE_HDF,                                                  ///< HDF tubing set
     NUM_OF_TUBE_SET_TYPES                                               ///< Number of tube set types