Index: firmware/App/Controllers/DrainPump.c
===================================================================
diff -u -r359cf587f2f935ef9f40a16d17c4105efa653c1d -r2510a84808ee5179d3f84f0b04f24c5a4122dbe5
--- firmware/App/Controllers/DrainPump.c	(.../DrainPump.c)	(revision 359cf587f2f935ef9f40a16d17c4105efa653c1d)
+++ firmware/App/Controllers/DrainPump.c	(.../DrainPump.c)	(revision 2510a84808ee5179d3f84f0b04f24c5a4122dbe5)
@@ -49,8 +49,7 @@
 
 #define DRAIN_PUMP_P_COEFFICIENT               0.005           //TODO DARA
 #define DRAIN_PUMP_I_COEFFICIENT               0.0015          //TODO DARA
-#define DRAIN_PUMP_TARGET_DELTA_PRESSURE       NEARLY_ZERO     //TODO dara
-
+
 /// Enumeration of drain pump states.
 typedef enum DrainPump_States
 {
@@ -89,16 +88,17 @@
 static PUMP_CONTROL_MODE_T drainPumpControlMode = PUMP_CONTROL_MODE_OPEN_LOOP;      ///< requested drain pump control mode.
 static PUMP_CONTROL_MODE_T drainPumpControlModeSet = PUMP_CONTROL_MODE_OPEN_LOOP;  ///< currently set drain pump control mode.
 
-static OVERRIDE_U32_T drainPumpDataPublishInterval = { DRAIN_PUMP_DATA_PUB_INTERVAL, DRAIN_PUMP_DATA_PUB_INTERVAL, 0, 0 };  ///< interval (in ms) at which to publish RO flow data to CAN bus.
-static OVERRIDE_U32_T targetDrainPumpSpeed = { 0, 0, 0, 0 };                        ///< Target RO pressure (in PSI).
+static OVERRIDE_U32_T drainPumpDataPublishInterval = { DRAIN_PUMP_DATA_PUB_INTERVAL,
+                                                       DRAIN_PUMP_DATA_PUB_INTERVAL,
+                                                       0, 0 };  ///< interval (in ms) at which to publish RO flow data to CAN bus
+static OVERRIDE_U32_T targetDrainPumpSpeed = { 0, 0, 0, 0 };                        ///< Target RO pressure (in PSI)
+static OVERRIDE_U32_T targetDrainPumpDeltaP = { 0, 0, 0, 0 };                       ///< Target delta pressure for the drain pump
 
 static U32 drainControlTimerCounter = 0;                                            ///< determines when to perform control on drain pump
 
 static DRAIN_PUMP_SELF_TEST_STATE_T drainPumpSelfTestState = DRAIN_PUMP_SELF_TEST_STATE_START;  ///< current drain pump self test state
 static U32 drainPumpSelfTestTimerCount = 0;                                         ///< timer counter for drain pump self test
 
-static BOOL hasClosedLoopBeenRequested = FALSE;
-
 // ********** private function prototypes **********
 
 static DRAIN_PUMP_STATE_T handleDrainPumpOffState( void );
@@ -135,20 +135,31 @@
  * @param rpm : new target drain pump speed (in RPM).
  * @return TRUE if new target speed is set, FALSE if not
  *************************************************************************/
-BOOL setDrainPumpTargetSpeed( U32 rpm, PUMP_CONTROL_MODE_T mode )
+BOOL setDrainPumpTargetSpeed( U32 rpm )
 {
-    BOOL result = FALSE;
+    BOOL result = FALSE;
 
     if ( ( 0 == rpm ) ||
          ( ( rpm >= MIN_DRAIN_PUMP_RPM_TARGET ) && ( rpm <= MAX_DRAIN_PUMP_RPM_TARGET ) ) )
     {
         drainPumpDAC = (U32)((F32)rpm * DRP_SPEED_RPM_TO_ADC_FACTOR + FLOAT_TO_INT_ROUNDUP_OFFSET);
         targetDrainPumpSpeed.data = rpm;
-        drainPumpControlMode = mode;
+        drainPumpControlMode = PUMP_CONTROL_MODE_OPEN_LOOP;
         result = TRUE;
     }
 
     return result;
+}
+
+BOOL setDrainPumpTargetDeltaPressure ( U32 deltaP )
+{
+    BOOL result = FALSE;
+
+    targetDrainPumpDeltaP.data = deltaP;
+    drainPumpControlMode = PUMP_CONTROL_MODE_CLOSED_LOOP;
+    result = TRUE;
+
+    return result;
 }
 
 /*********************************************************************//**
@@ -242,17 +253,13 @@
 
     // if we've been given a pressure, transition to open loop state
     // as it will not be controlling and it will just run
-    if ( getTargetDrainPumpSpeed() > 0 && !hasClosedLoopBeenRequested )
+    if ( getTargetDrainPumpSpeed() > 0 &&
+         drainPumpControlMode == PUMP_CONTROL_MODE_OPEN_LOOP )
     {
         // set drain pump enable pin
         SET_DRAIN_PUMP_ENABLE();
         // set drain pump control mode
         drainPumpControlModeSet = drainPumpControlMode;
-        // Check if drain pump mode is closed loop
-        //if ( drainPumpControlModeSet == PUMP_CONTROL_MODE_CLOSED_LOOP )
-        //{
-        //   resetPIController( PI_CONTROLLER_ID_DRAIN_PUMP, MIN_DRAIN_PUMP_RPM_TARGET );
-        //}
         // set drain pump DAC
         drainPumpDACSet = drainPumpDAC;
         setFPGADrainPumpSpeed( drainPumpDACSet );
@@ -261,16 +268,17 @@
         result = DRAIN_PUMP_OPEN_LOOP_STATE;
     }
 
-    if ( hasClosedLoopBeenRequested )
+    else if ( drainPumpControlMode ==  PUMP_CONTROL_MODE_OPEN_LOOP )
     {
        // set drain pump enable pin
        SET_DRAIN_PUMP_ENABLE();
        // set drain pump control mode
        drainPumpControlModeSet = drainPumpControlMode;
 
-
        resetPIController( PI_CONTROLLER_ID_DRAIN_PUMP, MIN_DRAIN_PUMP_RPM_TARGET );
 
+       U32 rpm = 500;
+       drainPumpDAC = (U32)((F32)rpm * DRP_SPEED_RPM_TO_ADC_FACTOR + FLOAT_TO_INT_ROUNDUP_OFFSET);
        // set drain pump DAC
        drainPumpDACSet = drainPumpDAC;
        setFPGADrainPumpSpeed( drainPumpDACSet );
@@ -303,7 +311,7 @@
             F32 inletDrainPressure = getMeasuredDGPressure ( PRESSURE_SENSOR_DRAIN_PUMP_INLET );
             F32 outletDrainPressure = getMeasuredDGPressure ( PRESSURE_SENSOR_DRAIN_PUMP_OUTLET );
             F32 pressureDiff = fabs( inletDrainPressure - outletDrainPressure );
-            F32 rpm = runPIController( PI_CONTROLLER_ID_DRAIN_PUMP, DRAIN_PUMP_TARGET_DELTA_PRESSURE, pressureDiff );
+            F32 rpm = runPIController( PI_CONTROLLER_ID_DRAIN_PUMP, targetDrainPumpDeltaP.data, pressureDiff );
             drainPumpDAC = (U32)((F32)rpm * DRP_SPEED_RPM_TO_ADC_FACTOR + FLOAT_TO_INT_ROUNDUP_OFFSET);
             setFPGADrainPumpSpeed( drainPumpDAC );
         }
@@ -507,7 +515,7 @@
         targetDrainPumpSpeed.ovInitData = targetDrainPumpSpeed.data; // backup current target pressure
         targetDrainPumpSpeed.ovData = value;
         targetDrainPumpSpeed.override = OVERRIDE_KEY;
-        result = setDrainPumpTargetSpeed( value, PUMP_CONTROL_MODE_OPEN_LOOP );
+        result = setDrainPumpTargetSpeed( value );
     }
 
     return result;
@@ -532,7 +540,7 @@
         targetDrainPumpSpeed.override = OVERRIDE_RESET;
         targetDrainPumpSpeed.ovInitData = 0;
         targetDrainPumpSpeed.ovData = 0;
-        result = setDrainPumpTargetSpeed( targetDrainPumpSpeed.data, PUMP_CONTROL_MODE_OPEN_LOOP );
+        result = setDrainPumpTargetSpeed( targetDrainPumpSpeed.data );
     }
 
     return result;