Index: firmware/App/Modes/Dialysis.c
===================================================================
diff -u -rcc511a2e779106c4fda8305c25bd1f9d9fbf06ce -r2df21d2472a8d79d78af7e359518acf3614accc5
--- firmware/App/Modes/Dialysis.c	(.../Dialysis.c)	(revision cc511a2e779106c4fda8305c25bd1f9d9fbf06ce)
+++ firmware/App/Modes/Dialysis.c	(.../Dialysis.c)	(revision 2df21d2472a8d79d78af7e359518acf3614accc5)
@@ -241,22 +241,41 @@
 BOOL pauseUF( void )
 {
     BOOL result = FALSE;
+    REQUEST_REJECT_REASON_CODE_T rejectReason = REQUEST_REJECT_REASON_NONE;
     TREATMENT_STATE_T trtState = getTreatmentState();
-    OP_MODE currMode = getCurrentOperationMode();
+    HD_OP_MODE_T currMode = getCurrentOperationMode();
 
     if ( ( MODE_TREA == currMode ) && ( TREATMENT_DIALYSIS_STATE == trtState ) &&
          ( DIALYSIS_UF_STATE == currentDialysisState ) && ( UF_RUNNING_STATE == currentUFState ) )
     {
+        result = TRUE;
         // set outlet pump to dialysate rate
-        result = setDialOutPumpTargetRate( setDialysateFlowRate, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_CLOSED_LOOP );
-
-        if ( TRUE == result )
+        setDialOutPumpTargetRate( setDialysateFlowRate, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_CLOSED_LOOP );
+        // go to UF paused state
+        currentUFState = UF_PAUSED_STATE;
+    }
+    else
+    {
+        if ( MODE_TREA != currMode )
         {
-            // go to UF paused state
-            currentUFState = UF_PAUSED_STATE;
+            rejectReason = REQUEST_REJECT_REASON_NOT_IN_TREATMENT_MODE;
         }
+        else if ( TREATMENT_DIALYSIS_STATE != trtState )
+        {
+            rejectReason = REQUEST_REJECT_REASON_INVALID_TREATMENT_STATE;
+        }
+        else if ( DIALYSIS_UF_STATE != currentDialysisState )
+        {
+            rejectReason = REQUEST_REJECT_REASON_SALINE_BOLUS_IN_PROGRESS;
+        }
+        else
+        {
+            rejectReason = REQUEST_REJECT_REASON_UF_NOT_IN_PROGESS;
+        }
     }
 
+    // TODO - send response w/ reason code if rejected
+
     return result;
 }
 
@@ -271,24 +290,43 @@
 BOOL resumeUF( void )
 {
     BOOL result = FALSE;
+    REQUEST_REJECT_REASON_CODE_T rejectReason = REQUEST_REJECT_REASON_NONE;
     TREATMENT_STATE_T trtState = getTreatmentState();
-    OP_MODE currMode = getCurrentOperationMode();
+    HD_OP_MODE_T currMode = getCurrentOperationMode();
 
     if ( ( MODE_TREA == currMode ) && ( TREATMENT_DIALYSIS_STATE == trtState ) &&
          ( DIALYSIS_UF_STATE == currentDialysisState ) && ( UF_PAUSED_STATE == currentUFState ) )
     {
+        result = TRUE;
         // set outlet pump to dialysate rate + set UF rate
-        result = setDialOutPumpTargetRate( setDialysateFlowRate + FLOAT_TO_INT_WITH_ROUND( setUFRate ), MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_CLOSED_LOOP );
-
-        if ( TRUE == result )
+        setDialOutPumpTargetRate( setDialysateFlowRate + FLOAT_TO_INT_WITH_ROUND( setUFRate ), MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_CLOSED_LOOP );
+        // restart UF time accumulation for reference volume calculation
+        lastUFTimeStamp = getMSTimerCount();
+        // go to UF paused state
+        currentUFState = UF_RUNNING_STATE;
+    }
+    else
+    {
+        if ( MODE_TREA != currMode )
         {
-            // restart UF time accumulation for reference volume calculation
-            lastUFTimeStamp = getMSTimerCount();
-            // go to UF paused state
-            currentUFState = UF_RUNNING_STATE;
+            rejectReason = REQUEST_REJECT_REASON_NOT_IN_TREATMENT_MODE;
         }
+        else if ( TREATMENT_DIALYSIS_STATE != trtState )
+        {
+            rejectReason = REQUEST_REJECT_REASON_INVALID_TREATMENT_STATE;
+        }
+        else if ( DIALYSIS_UF_STATE != currentDialysisState )
+        {
+            rejectReason = REQUEST_REJECT_REASON_SALINE_BOLUS_IN_PROGRESS;
+        }
+        else
+        {
+            rejectReason = REQUEST_REJECT_REASON_UF_NOT_PAUSED;
+        }
     }
 
+    // TODO - send response w/ reason code if rejected
+
     return result;
 }