Index: firmware/App/Controllers/ConcentratePumps.c
===================================================================
diff -u -r80028d3b1eef322950c1a5b74c282df2ba989ff5 -r3f22d883958a14b6193d6cd59c9acdbbd359b69e
--- firmware/App/Controllers/ConcentratePumps.c	(.../ConcentratePumps.c)	(revision 80028d3b1eef322950c1a5b74c282df2ba989ff5)
+++ firmware/App/Controllers/ConcentratePumps.c	(.../ConcentratePumps.c)	(revision 3f22d883958a14b6193d6cd59c9acdbbd359b69e)
@@ -36,6 +36,7 @@
 #define CONCENTRATE_PUMP_MIN_SPEED                          3.0                                                 ///< Minimum speed for concentrate pump in mL per min.
 #define CONCENTRATE_PUMP_MAX_SPEED                          49.0                                                ///< Maximum speed for concentrate pump in mL per min.
 #define CONCENTRATE_PUMP_ERROR_TOLERANCE                    0.02                                                ///< Measured speed needs to be within 2% of commanded speed.
+#define CONCENTRATE_PUMP_ZERO_FLOW_RATE_PULSE_WIDTH         0xFFFF                                              ///< Pulse width value when zero flow rate or pump is off.
 
 #define CONCENTRATE_PUMP_VOLUME_PER_REV                     0.15                                                ///< Volume output every revolution (mL).
 #define CONCENTRATE_PUMP_PULSE_PER_REV                      4.0                                                 ///< Number of pulses generate for every revolution.
@@ -83,7 +84,9 @@
 
 static void stepConcentratePumpToTargetSpeed( CONCENTRATE_PUMPS_T pumpId );
 static CONCENTRATE_PUMP_STATE_T handleConcentratePumpOnState( void );
+
 static U32 getPublishConcentratePumpDataInterval( void );
+static void calcMeasuredPumpsSpeed( CONCENTRATE_PUMPS_T pumpId, U16 pulseWidthCount );
 static F32 getMeasuredPumpSpeed( CONCENTRATE_PUMPS_T pumpId );
 
 /*********************************************************************//**
@@ -122,20 +125,17 @@
     {
         CONCENTRATE_PUMP_DATA_T data;
 
-        F32 const cp1PulseWidthInSecond = (F32)( getFPGACP1HallSensePulseWidth() * CONCENTRATE_PUMP_HALL_SENSE_PERIOD_RESOLUTION ) / US_PER_SECOND;
-        F32 const cp2PulseWidthInSecond = (F32)( getFPGACP2HallSensePulseWidth() * CONCENTRATE_PUMP_HALL_SENSE_PERIOD_RESOLUTION ) / US_PER_SECOND;
+        calcMeasuredPumpsSpeed( CONCENTRATEPUMPS_CP1, getFPGACP1HallSensePulseWidth() );
+        calcMeasuredPumpsSpeed( CONCENTRATEPUMPS_CP2, getFPGACP2HallSensePulseWidth() );
 
-        measuredPumpSpeed[ CONCENTRATEPUMPS_CP1 ].data = ( 1 / cp1PulseWidthInSecond ) * CONCENTRATE_PUMP_VOLUME_PER_PULSE * SEC_PER_MIN;
-        measuredPumpSpeed[ CONCENTRATEPUMPS_CP2 ].data = ( 1 / cp2PulseWidthInSecond ) * CONCENTRATE_PUMP_VOLUME_PER_PULSE * SEC_PER_MIN;
-
-        F32 const cp1Error =  fabs( getMeasuredPumpSpeed( CONCENTRATEPUMPS_CP1 ) - pumpTargetSpeed[ CONCENTRATEPUMPS_CP1 ] ) / pumpTargetSpeed[ CONCENTRATEPUMPS_CP1 ];
-        F32 const cp2Error =  fabs( getMeasuredPumpSpeed( CONCENTRATEPUMPS_CP2 ) - pumpTargetSpeed[ CONCENTRATEPUMPS_CP2 ] ) / pumpTargetSpeed[ CONCENTRATEPUMPS_CP2 ];
-
         data.cp1TargetSpeed   = pumpTargetSpeed[ CONCENTRATEPUMPS_CP1 ];
         data.cp1MeasuredSpeed = getMeasuredPumpSpeed( CONCENTRATEPUMPS_CP1 );
         data.cp2TargetSpeed   = pumpTargetSpeed[ CONCENTRATEPUMPS_CP2 ];
         data.cp2MeasuredSpeed = getMeasuredPumpSpeed( CONCENTRATEPUMPS_CP2 );
 
+        F32 const cp1Error =  fabs( getMeasuredPumpSpeed( CONCENTRATEPUMPS_CP1 ) - currentPumpSpeed[ CONCENTRATEPUMPS_CP1 ] ) / currentPumpSpeed[ CONCENTRATEPUMPS_CP1 ];
+        F32 const cp2Error =  fabs( getMeasuredPumpSpeed( CONCENTRATEPUMPS_CP2 ) - currentPumpSpeed[ CONCENTRATEPUMPS_CP2 ] ) / currentPumpSpeed[ CONCENTRATEPUMPS_CP2 ];
+
         checkPersistentAlarm( PERSISTENT_ALARM_CP1_SPEED_CONTROL_ERROR, cp1Error > CONCENTRATE_PUMP_ERROR_TOLERANCE, cp1Error );
         checkPersistentAlarm( PERSISTENT_ALARM_CP2_SPEED_CONTROL_ERROR, cp2Error > CONCENTRATE_PUMP_ERROR_TOLERANCE, cp2Error );
 
@@ -372,6 +372,27 @@
 
 /*********************************************************************//**
  * @brief
+ * The calcMeasuredPumpsSpeed function calculates the concentrate pump flow
+ * rate using the hall sense pulse width count.
+ * @details Inputs: none
+ * @details Outputs: measuredPumpSpeed
+ * @param pumpId concentrate pump id to increase current step speed
+ * @param pulseWidthCount hall sense pulse width count reading from FPGA
+ * @return none
+ *************************************************************************/
+static void calcMeasuredPumpsSpeed( CONCENTRATE_PUMPS_T pumpId, U16 pulseWidthCount )
+{
+    F32 const pulseWidthInSecond = (F32)( pulseWidthCount * CONCENTRATE_PUMP_HALL_SENSE_PERIOD_RESOLUTION ) / US_PER_SECOND;
+    measuredPumpSpeed[ pumpId ].data = ( 1 / pulseWidthInSecond ) * CONCENTRATE_PUMP_VOLUME_PER_PULSE * SEC_PER_MIN;
+
+    if ( CONCENTRATE_PUMP_ZERO_FLOW_RATE_PULSE_WIDTH == pulseWidthCount )
+    {
+        measuredPumpSpeed[ pumpId ].data = 0.0;
+    }
+}
+
+/*********************************************************************//**
+ * @brief
  * The getMeasuredPumpSpeed function gets the measured concentrate pump flow rate.
  * @details Inputs: measuredPumpSpeed
  * @details Outputs: none