Index: firmware/App/Controllers/DialInFlow.c
===================================================================
diff -u -rf861c4c5ab64f429e0b8b9cc456e2ed14e472f2b -rb5756e5b5041288a2e95585990cce5a93756d693
--- firmware/App/Controllers/DialInFlow.c	(.../DialInFlow.c)	(revision f861c4c5ab64f429e0b8b9cc456e2ed14e472f2b)
+++ firmware/App/Controllers/DialInFlow.c	(.../DialInFlow.c)	(revision b5756e5b5041288a2e95585990cce5a93756d693)
@@ -41,7 +41,8 @@
 
 #define DIAL_IN_FLOW_DATA_PUB_INTERVAL        ( MS_PER_SECOND / TASK_PRIORITY_INTERVAL )  ///< interval (ms/task time) at which the dialIn flow data is published on the CAN bus
 
-#define MAX_DIAL_IN_PUMP_PWM_STEP_CHANGE      0.01            ///< duty cycle    TODO - fixed or parameterized or set in motor controller?
+#define MAX_DIAL_IN_PUMP_PWM_STEP_UP_CHANGE   0.0133          ///< max duty cycle change when ramping up ~ 200 mL/min/s.
+#define MAX_DIAL_IN_PUMP_PWM_STEP_DN_CHANGE   0.02            ///< max duty cycle change when ramping down ~ 300 mL/min/s.
 #define MAX_DIAL_IN_PUMP_PWM_DUTY_CYCLE       0.88            ///< controller will error if PWM duty cycle > 90%, so set max to 88%
 #define MIN_DIAL_IN_PUMP_PWM_DUTY_CYCLE       0.12            ///< controller will error if PWM duty cycle < 10%, so set min to 12%
 
@@ -435,7 +436,7 @@
     if ( getTargetDialInFlowRate() != 0 )
     {
         // set initial PWM duty cycle
-        dialInPumpPWMDutyCyclePctSet = DIP_PWM_ZERO_OFFSET + MAX_DIAL_IN_PUMP_PWM_STEP_CHANGE;
+        dialInPumpPWMDutyCyclePctSet = DIP_PWM_ZERO_OFFSET + MAX_DIAL_IN_PUMP_PWM_STEP_UP_CHANGE;
         setDialInPumpControlSignalPWM( dialInPumpPWMDutyCyclePctSet );
         // allow dialIn pump to run in requested direction
         setDialInPumpDirection( dialInPumpDirection );
@@ -464,7 +465,7 @@
     if ( 0 == getTargetDialInFlowRate() )
     {
         // start ramp down to stop
-        dialInPumpPWMDutyCyclePctSet -= MAX_DIAL_IN_PUMP_PWM_STEP_CHANGE;
+        dialInPumpPWMDutyCyclePctSet -= MAX_DIAL_IN_PUMP_PWM_STEP_DN_CHANGE;
         setDialInPumpControlSignalPWM( dialInPumpPWMDutyCyclePctSet );
         result = DIAL_IN_PUMP_RAMPING_DOWN_STATE;
     }
@@ -485,7 +486,7 @@
     // continue ramp up
     else
     {
-        dialInPumpPWMDutyCyclePctSet += MAX_DIAL_IN_PUMP_PWM_STEP_CHANGE;
+        dialInPumpPWMDutyCyclePctSet += MAX_DIAL_IN_PUMP_PWM_STEP_UP_CHANGE;
         setDialInPumpControlSignalPWM( dialInPumpPWMDutyCyclePctSet );
     }
 
@@ -506,7 +507,7 @@
     DIAL_IN_PUMP_STATE_T result = DIAL_IN_PUMP_RAMPING_DOWN_STATE;
 
     // have we essentially reached zero speed
-    if ( dialInPumpPWMDutyCyclePctSet < (MAX_DIAL_IN_PUMP_PWM_STEP_CHANGE + DIP_PWM_ZERO_OFFSET) )
+    if ( dialInPumpPWMDutyCyclePctSet < (MAX_DIAL_IN_PUMP_PWM_STEP_UP_CHANGE + DIP_PWM_ZERO_OFFSET) )
     {
         stopDialInPump();
         result = DIAL_IN_PUMP_OFF_STATE;
@@ -528,7 +529,7 @@
     // continue ramp down
     else
     {
-        dialInPumpPWMDutyCyclePctSet -= MAX_DIAL_IN_PUMP_PWM_STEP_CHANGE;
+        dialInPumpPWMDutyCyclePctSet -= MAX_DIAL_IN_PUMP_PWM_STEP_DN_CHANGE;
         setDialInPumpControlSignalPWM( dialInPumpPWMDutyCyclePctSet );
     }