Index: firmware/App/Modes/SalineBolus.c
===================================================================
diff -u -r1a36e9bd718b40ceaee21dd12eca2da353828e30 -r0bb3fe3f34c02bd19c36aff2b98876e46a2ad177
--- firmware/App/Modes/SalineBolus.c	(.../SalineBolus.c)	(revision 1a36e9bd718b40ceaee21dd12eca2da353828e30)
+++ firmware/App/Modes/SalineBolus.c	(.../SalineBolus.c)	(revision 0bb3fe3f34c02bd19c36aff2b98876e46a2ad177)
@@ -15,7 +15,6 @@
 *
 ***************************************************************************/
 
-
 #include "BloodFlow.h"
 #include "Dialysis.h"
 #include "ModeTreatment.h"
@@ -44,6 +43,7 @@
 static U32 salineBolusBroadcastTimerCtr;              ///< Saline bolus data broadcast timer counter used to schedule when to transmit data.
 static BOOL salineBolusStartRequested;                ///< Flag indicates a saline bolus start has been requested by user.
 static BOOL salineBolusAbortRequested;                ///< Flag indicates a salien bolus abort has been requested by user.
+static BOOL airTrapFillInProgress;                    ///< Flag indicates an air trap fill is in progress.
 
 static F32 totalSalineVolumeDelivered_mL;             ///< Volume (mL) in total of saline delivered so far (cumulative for all boluses including current one).
 static F32 bolusSalineVolumeDelivered_mL;             ///< Volume (mL) of current bolus delivered so far (calculated from measured blood flow rate).
@@ -74,6 +74,7 @@
     bolusSalineVolumeDelivered_mL  = 0.0;
     salineBolusStartRequested      = FALSE;
     salineBolusAbortRequested      = FALSE;
+    airTrapFillInProgress          = FALSE;
     bolusSalineLastVolumeTimeStamp = getMSTimerCount();
 }
 
@@ -90,6 +91,7 @@
     bolusSalineVolumeDelivered_mL = 0.0;
     salineBolusStartRequested     = FALSE;
     salineBolusAbortRequested     = FALSE;
+    airTrapFillInProgress         = FALSE;
     currentSalineBolusState       = SALINE_BOLUS_STATE_IDLE;
     resetUF();
 }
@@ -125,6 +127,8 @@
             break;
     }
 
+    airTrapFillInProgress = isAirTrapFillInProgress();
+
     if ( priorSubState != currentSalineBolusState )
     {
         setCurrent4thLevelState( (U32)currentSalineBolusState );
@@ -217,7 +221,7 @@
     }
     else if ( ( TRUE == isAnyAlarmActive() ) && ( ( TRUE == isBloodRecircBlocked() ) || ( TRUE == isRinseBackBlocked() ) ) )
     {
-        // Any alarm can be active but blood recirculation and dialysate recirculation cannot be blocked in their properties in order
+        // Any alarm can be active but blood recirculation and rinseback cannot be blocked in their properties in order
         // to do saline bolus
         rejReason = REQUEST_REJECT_REASON_SALINE_BOLUS_NOT_ALLOWED;
     }
@@ -395,6 +399,23 @@
     bolusSalineVolumeDelivered_mL += volSinceLastUpdateMl;
     totalSalineVolumeDelivered_mL += volSinceLastUpdateMl;
 
+    // if an air trap fill has started, set BP rate and VBV state accordingly
+    if ( ( airTrapFillInProgress != TRUE ) && ( TRUE == isAirTrapFillInProgress() ) )
+    {
+        // set BP to air trap fill rate if air trap fill has been initiated
+        setBloodPumpTargetFlowRate( AIR_TRAP_FILL_BLOOD_FLOW_RATE, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_CLOSED_LOOP );
+        // close VBV for fill
+        setValvePosition( VBV, VALVE_POSITION_C_CLOSE );
+    }
+    // if an air trap fill has completed, restore BP and VBV to saline bolus
+    else if ( ( TRUE == airTrapFillInProgress ) && ( isAirTrapFillInProgress() != TRUE ) )
+    {
+        // Set to patient in case VBV is closed in treatment stop
+        setValvePosition( VBV, VALVE_POSITION_B_OPEN );
+        // Start blood pump at saline bolus rate
+        setBloodPumpTargetFlowRate( SALINE_BOLUS_FLOW_RATE, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_CLOSED_LOOP );
+    }
+
     // Check for empty saline bag per arterial line pressure
     if ( TRUE == isSalineBagEmpty() )
     {