Index: firmware/App/Controllers/DialOutFlow.c
===================================================================
diff -u -r5e77f78c5dee9dfb441bd5d2053f7f4ac50dc619 -r29e57b5232f605a871c62580e16a7db297aae992
--- firmware/App/Controllers/DialOutFlow.c	(.../DialOutFlow.c)	(revision 5e77f78c5dee9dfb441bd5d2053f7f4ac50dc619)
+++ firmware/App/Controllers/DialOutFlow.c	(.../DialOutFlow.c)	(revision 29e57b5232f605a871c62580e16a7db297aae992)
@@ -55,8 +55,10 @@
 
 #define DOP_HOME_RATE                           100             ///< target pump speed (in estimate mL/min) for homing.
 #define DOP_HOME_TIMEOUT_MS                     10000           ///< maximum time allowed for homing to complete (in ms).
-#define DOP_SPEED_CALC_INTERVAL                 ( 40 / TASK_PRIORITY_INTERVAL )  ///< interval (ms/task time) at which the dialysate outlet pump speed is calculated.
-#define DOP_SPEED_CALC_BUFFER__LEN              25              ///< number of hall sensor counts kept in buffer to hold last 1 second of count data.
+/// interval (ms/task time) at which the blood pump speed is calculated (every 40 ms).
+#define DOP_SPEED_CALC_INTERVAL                 ( 40 / TASK_PRIORITY_INTERVAL )
+/// number of hall sensor counts kept in buffer to hold last 1 second of count data.
+#define DOP_SPEED_CALC_BUFFER__LEN              ( 1000 / DOP_SPEED_CALC_INTERVAL / TASK_PRIORITY_INTERVAL )
 #define DOP_HALL_EDGE_COUNTS_PER_REV            48              ///< number of hall sensor edge counts per motor revolution.
 
 #define DOP_MAX_MOTOR_SPEED_WHILE_OFF_RPM       100.0           ///< maximum motor speed (RPM) while motor is commanded off.
@@ -750,7 +752,9 @@
     {
         U16 dopMotorHallSensorCount = getFPGADialOutPumpHallSensorCount();
         U32 nextIdx = INC_WRAP( dopMotorSpeedCalcIdx, 0, DOP_SPEED_CALC_BUFFER__LEN - 1 );
-        U16 incDelta = ( dopMotorHallSensorCount >= dopLastMotorHallSensorCounts[ nextIdx ] ? dopMotorHallSensorCount - dopLastMotorHallSensorCounts[ nextIdx ] : ( HEX_64_K - dopLastMotorHallSensorCounts[ nextIdx ] ) + dopMotorHallSensorCount );
+        U16 incDelta = ( dopMotorHallSensorCount >= dopLastMotorHallSensorCounts[ dopMotorSpeedCalcIdx ] ? \
+                         dopMotorHallSensorCount - dopLastMotorHallSensorCounts[ dopMotorSpeedCalcIdx ] : \
+                         ( HEX_64_K - dopLastMotorHallSensorCounts[ dopMotorSpeedCalcIdx ] ) + dopMotorHallSensorCount );
         U16 decDelta = HEX_64_K - incDelta;
         U16 delta;