Index: firmware/App/Controllers/BalancingChamber.h
===================================================================
diff -u -r6d0bd19fb192dcd272fa773e8833862cc8a8f750 -rc4e1d97e73dd863ddffe895833d209e172b5ae4a
--- firmware/App/Controllers/BalancingChamber.h	(.../BalancingChamber.h)	(revision 6d0bd19fb192dcd272fa773e8833862cc8a8f750)
+++ firmware/App/Controllers/BalancingChamber.h	(.../BalancingChamber.h)	(revision c4e1d97e73dd863ddffe895833d209e172b5ae4a)
@@ -38,15 +38,15 @@
 #define BC_FRESH_FILL_PRESSURE_PSIG                 15.0F              ///< Fresh side pressure (drop) during balancing chamber switching, indicates fill has been started / in progress.
 #define BC_SPENT_FILL_PRESSURE_PSIG                 29.0F              ///< Spent side pressure (drop) during balancing chamber switching, indicates fill has been started / in progress.
 #define BAL_CHAMBER_FILL_VOLUME_ML                  30.0F              ///< Balancing chamber fill/drain volume per batch operation.
+#define BAL_CHAMBER_TIME_BASED_D48_SPEED_RPM        250                ///< Minimum D48 speed and fixed speed for time-based balancing chamber switching.
 
 /// balancing chamber data structure
 typedef struct
 {
     U32 balChamberExecState;                                            ///< Balancing chamber execution state
     U32 balChamberSWState;                                              ///< Balancing chamber switching state (state 1 or state 2)
     F32 balChamberSWFreq;                                               ///< Balancing chamber switching frequency
-    U32 balChamberSwPeriod;                                             ///< Balancing chamber switching period
-    BOOL isBalChamberFillInProgress;                                    ///< Whether balancing chamber fill in progress or not
+    BOOL isSpentFillComplete;                                           ///< Whether balancing chamber spent fill completed or not
     U32 currentBalChamberSwitchingCounter;                              ///< Current balancing chamber switching counter
     BOOL isPressureStabilizedDuringFill;                                ///< Whether pressure stabilized during fill or not
     BOOL balChamberSWOnlyState;                                         ///< Balancing chamber switching only status ( On/Off)
@@ -63,6 +63,7 @@
 void updateBalChamberSwitchingPeriod( void );                            // Update the balancing chamber switching period
 BAL_CHAMBER_EXEC_STATE_T getCurrentBalancingChamberExecState( void );    // Get the current state of the balancing chamber execution
 F32 getBalChamberSwitchingFreq( void );                                  // Get the balancing chamber switching frequency
+F32 getBalChamberActiveDialysateFlowrate( void );                        // Get the active Qd used by balancing chamber timing
 U32 getDialDeliveryProgressStatus( void );                               // Get the dialysate delivery in progress status
 BOOL getBalancingChamberFillinProgressStatus( void );                    // Get the balancing chamber fill in progress status
 void valveControlForBCClosedState( void );                               // Closes all balancing chamber valves