Index: DDDefs.h
===================================================================
diff -u -r9a27718ab20fb9f62899d1812125c1d8e0856054 -r4e174a6da0995a4c4813a766862e2a63022e7e14
--- DDDefs.h	(.../DDDefs.h)	(revision 9a27718ab20fb9f62899d1812125c1d8e0856054)
+++ DDDefs.h	(.../DDDefs.h)	(revision 4e174a6da0995a4c4813a766862e2a63022e7e14)
@@ -7,8 +7,8 @@
 *
 * @file    DDDefs.h
 *
-* @author  (last)      Arpita Srivastava
-* @date    (last)      26-Feb-2026
+* @author  (last)      Michael Garthwaite
+* @date    (last)      14-Apr-2026
 *
 * @author  (original)  Sean Nash
 * @date    (original)  01-Aug-2024
@@ -524,7 +524,7 @@
 };
 typedef enum Bicarb_Chamber_F_Fill_Exec_States BICARB_CHAMBER_FILL_EXEC_STATE_T;  ///< Type for bicarb chamber fill exec state enumeration
 
-//Enumeration of Bicarb chmaber drain mode exec states
+/// Enumeration of Bicarb chmaber drain mode exec states
 enum Dry_Bicart_Drain_Exec_States
 {
     DRY_BICART_DRAIN_START_STATE = 0,                                 ///< Initial state of dry bicart drain
@@ -535,6 +535,23 @@
 };
 typedef enum Dry_Bicart_Drain_Exec_States DRY_BICART_DRAIN_EXEC_STATE_T;    ///< Type for dry bicart fill exec state enumeration
 
+/// Enumeration of conductivity sensors.
+enum Conductivity_Sensors
+{
+    D17_COND = 0,                                       ///< Bicarb only conductivity sensor - 1
+    FIRST_DD_COND_SENSOR = D17_COND,                    ///< First conductivity sensor
+    D27_COND,                                           ///< Acid and Bicarb mix conductivity sensor - 1
+    D29_COND,                                           ///< Acid and Bicarb mix conductivity sensor - 2
+    D43_COND,                                           ///< Spent dialysate conductivity sensor
+    D74_COND,                                           ///< Bicarb only conductivity sensor - 2
+    LAST_DD_COND_SENSOR = D74_COND,                     ///< Last conductivity sensor
+    P9_COND,                                            ///< Inlet water conductivity sensor
+    FIRST_FP_COND_SENSOR = P9_COND,                     ///< First FP conductivity sensor
+    P18_COND,                                           ///< RO outlet water conductivity sensor
+    LAST_FP_COND_SENSOR = P18_COND,                     ///< Last FP conductivity sensor
+    NUM_OF_CONDUCTIVITY_SENSORS                         ///< Number of conductivity sensors
+};
+typedef enum Conductivity_Sensors CONDUCTIVITY_SENSORS_T; ///< Type for conductivity sensor enumeration.
 /**@}*/
 
 #endif