Index: firmware/App/Modes/ModePreTreat.c
===================================================================
diff -u -r2f282113c1540be57b9d00833224d7ce93d460cd -r06462a7f903d6ac4835125746b6b6394be4601ae
--- firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 2f282113c1540be57b9d00833224d7ce93d460cd)
+++ firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 06462a7f903d6ac4835125746b6b6394be4601ae)
@@ -39,15 +39,16 @@
 
 // ********** private function prototypes **********
 
-static TD_PRE_TREATMENT_MODE_STATE_T handleWaterSampleState( void );        ///< Handle Water Sample state during Pre-Treatment
-static TD_PRE_TREATMENT_MODE_STATE_T handleSelfTestConsumableState( void ); ///< Handle Self Test Consumable state during Pre-Treatment
-static TD_PRE_TREATMENT_MODE_STATE_T handleSelfTestNoCartState( void );     ///< Handle Self Test No Cart state during Pre-Treatment
-static TD_PRE_TREATMENT_MODE_STATE_T handleInstallState( void );            ///< Handle Install state during Pre-Treatment
-static TD_PRE_TREATMENT_MODE_STATE_T handleSelfTestDryState( void );        ///< Handle Self Test Dry state during Pre-Treatment
-static TD_PRE_TREATMENT_MODE_STATE_T handlePrimeState( void );              ///< Handle Prime state during Pre-Treatment
-static TD_PRE_TREATMENT_MODE_STATE_T handleRecirculateState( void );        ///< Handle Recirculate state during Pre-Treatment
-static TD_PRE_TREATMENT_MODE_STATE_T handleRxState( void );                 ///< Handle Confirm Rx state during Pre-Treatment
-static TD_PRE_TREATMENT_MODE_STATE_T handlePatientConnectionState( void );  ///< Handle Patient Connection state during Pre-Treatment
+static void setPreTreatStateTransition( void );                                 ///< Configure actuators and variables for Pre-Treatment state transitions.
+static TD_PRE_TREATMENT_MODE_STATE_T handleWaterSampleState( void );            ///< Handle Water Sample state during Pre-Treatment
+static TD_PRE_TREATMENT_MODE_STATE_T handleSelfTestConsumableState( void );     ///< Handle Self Test Consumable state during Pre-Treatment
+static TD_PRE_TREATMENT_MODE_STATE_T handleSelfTestNoCartState( void );         ///< Handle Self Test No Cart state during Pre-Treatment
+static TD_PRE_TREATMENT_MODE_STATE_T handleInstallState( void );                ///< Handle Install state during Pre-Treatment
+static TD_PRE_TREATMENT_MODE_STATE_T handleSelfTestDryState( void );            ///< Handle Self Test Dry state during Pre-Treatment
+static TD_PRE_TREATMENT_MODE_STATE_T handlePrimeState( void );                  ///< Handle Prime state during Pre-Treatment
+static TD_PRE_TREATMENT_MODE_STATE_T handleRecirculateState( void );            ///< Handle Recirculate state during Pre-Treatment
+static TD_PRE_TREATMENT_MODE_STATE_T handleRxState( void );                     ///< Handle Confirm Rx state during Pre-Treatment
+static TD_PRE_TREATMENT_MODE_STATE_T handlePatientConnectionState( void );      ///< Handle Patient Connection state during Pre-Treatment
 
 /*********************************************************************//**
 * @brief
@@ -102,6 +103,7 @@
 U32 execPreTreatmentMode( void )
 {
     BOOL stop = isStopButtonPressed();
+    TD_PRE_TREATMENT_MODE_STATE_T prevPreTreatmentState = currentPreTreatmentState;
 
     if ( TRUE == stop )
     {
@@ -153,10 +155,57 @@
             break;
     }
 
+    if ( prevPreTreatmentState != currentPreTreatmentState )
+    {
+        setPreTreatStateTransition();
+    }
+
     return (U32)currentPreTreatmentState;
 }
 
 /*********************************************************************//**
+* @brief
+* The setPreTreatStateTransition function sets the actuators and variables
+* for the state transition in Pre-Treatment mode.
+* @details \b Inputs: currentPreTreatmentState
+* @details \b Outputs: Actuate valves, pumps as desired
+* @return none
+**************************************************************************/
+static void setPreTreatStateTransition( void )
+{
+    switch ( currentPreTreatmentState )
+    {
+        case TD_PRE_TREATMENT_TUBING_SET_INSTALL_STATE:
+            signalBloodPumpHardStop();
+            break;
+
+        case TD_PRE_TREATMENT_SELF_TEST_DRY_STATE:
+            // TODO: actuator configuration
+            break;
+
+        case TD_PRE_TREATMENT_PRIME_STATE:
+            // TODO: actuator configuration
+            break;
+
+        case TD_PRE_TREATMENT_CONFIRM_RX_STATE:
+            // No action required.
+            break;
+
+        case TD_PRE_TREATMENT_RECIRCULATE_STATE:
+            // No action required.
+            break;
+
+        case TD_PRE_TREATMENT_PATIENT_CONNECTION_STATE:
+            // TODO: actuator configuration
+            break;
+
+        default:
+            SET_ALARM_WITH_2_U32_DATA( ALARM_ID_TD_SOFTWARE_FAULT, SW_FAULT_ID_MODE_PRE_TREATMENT_INVALID_STATE, (U32)currentPreTreatmentState );
+            break;
+    }
+}
+
+/*********************************************************************//**
  * @brief
  * The handleWaterSampleState function executes the Water Sample state of
  * pre-treatment mode.