Index: Common.h
===================================================================
diff -u -rb16fb44ffe64e6ceb3e182d11485c3bb75dbad8f -r0b980cfad231f44b9805699b91a1f70a373e2a17
--- Common.h	(.../Common.h)	(revision b16fb44ffe64e6ceb3e182d11485c3bb75dbad8f)
+++ Common.h	(.../Common.h)	(revision 0b980cfad231f44b9805699b91a1f70a373e2a17)
@@ -60,14 +60,22 @@
     NUM_OF_SELF_TEST_STATUS                         ///< Number of self-test status
 } SELF_TEST_STATUS_T;
 
-/// List of 2-way states.
-typedef enum Two_Way_States
+/// List of open / closed states.
+typedef enum Open_Closed_States
 {
     STATE_CLOSED = 0,                               ///< Closed state
     STATE_OPEN,                                     ///< Open state
-    NUM_OF_OPN_CLS_STATES                           ///< Number of 2-way states
+    NUM_OF_OPN_CLS_STATES                           ///< Number of open / closed states
 } OPN_CLS_STATE_T;
 
+/// List of 3-way valve states.
+typedef enum Valve_3_Way_States
+{
+    VALVE_3WAY_COMMON_TO_CLOSED_STATE = 0,          ///< Common to closed state for 3-way valve
+    VALVE_3WAY_COMMON_TO_OPEN_STATE,                ///< Common to open state for 3-way valve
+    NUM_OF_VALVE_3WAY_STATES                        ///< Number of 3-way valve states
+} VALVE_3WAY_STATE_T;
+
 /// List of motor directions.
 typedef enum Motor_Directions
 {
@@ -86,6 +94,8 @@
 
 // **** Common Definitions ****
 
+#define ON                              1           ///< On.
+#define OFF                             0           ///< Off.
 #define NEARLY_INFINITY                 1.0E20      ///< Value that is nearly infinity.
 #define NEARLY_ZERO                     0.00000001F ///< Value that is nearly zero.  Used for floating point zero comparisons (e.g. divide by zero checks)
 #define HEX_64_K                        0x10000     ///< 64K (65536 in decimal)