Index: firmware/App/Controllers/PresOccl.c
===================================================================
diff -u -r921034ee7092206a50183eacfaa73b436d2dee5f -raceb6e5388e905d119c5c379bc97ced0720aa270
--- firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision 921034ee7092206a50183eacfaa73b436d2dee5f)
+++ firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision aceb6e5388e905d119c5c379bc97ced0720aa270)
@@ -66,6 +66,7 @@
 #define VENOUS_PRESSURE_MAX_MMHG            ( 2000.0F )                                     ///< Maximum venous pressure reading (in mmHg) for range check.
 #define VENOUS_PRESSURE_MIN_MMHG            ( -1500.0F )                                    ///< Minimum venous pressure reading (in mmHg) for range check.
 #define VENOUS_PRESSURE_ND_MAX_MMHG         ( 300.0F )                                      ///< Maximum venous pressure reading (in mmHg) when not dialyzing.
+#define VENOUS_PRESSURE_OCCL_OFFSET_MMHG    ( 50.0F )                                       ///< Venous pressure occlusion threshold offset from max alarm limit (in mmHg).
 
 #define PSI_TO_MMHG                         ( 51.7149F )                                    ///< Conversion factor for converting PSI to mmHg.
 
@@ -91,7 +92,8 @@
 #define EMPTY_SALINE_BAG_THRESHOLD_MMHG     -300.0F                                         ///< Threshold below which the saline bag is considered empty (in mmHg).  TODO - get real threshold from Systems
 static const U32 EMPTY_SALINE_BAG_PERSISTENCE = ( 250 / TASK_GENERAL_INTERVAL );            ///< Time that saline bag looks empty before saying it is empty.
 
-#define PRES_ALARM_PERSISTENCE              ( 1 * MS_PER_SECOND )                           ///< Alarm persistence period for pressure alarms.
+#define PRES_ALARM_PERSISTENCE              ( 1 * MS_PER_SECOND )                           ///< Alarm persistence period for pressure alarms.
+#define VEN_OCCL_ALARM_PERSISTENCE          100                                             ///< Alarm persistence period for venous occlusion alarm.
 
 /// Measured arterial pressure is filtered w/ 10 second moving average for pressure compensation of flow.
 #define SIZE_OF_LONG_ART_ROLLING_AVG        ( ( MS_PER_SECOND / TASK_GENERAL_INTERVAL ) * 10 )
@@ -197,6 +199,7 @@
     initPersistentAlarm( ALARM_ID_HD_ARTERIAL_PRESSURE_OUT_OF_RANGE, 0, PRES_ALARM_PERSISTENCE );
     initPersistentAlarm( ALARM_ID_HD_VENOUS_PRESSURE_OUT_OF_RANGE, 0, PRES_ALARM_PERSISTENCE );
     initPersistentAlarm( ALARM_ID_HD_BP_OCCLUSION_OUT_OF_RANGE, 0, PRES_ALARM_PERSISTENCE );
+    initPersistentAlarm( ALARM_ID_HD_VENOUS_LINE_OCCLUSION, 0, VEN_OCCL_ALARM_PERSISTENCE );
 
     lastArterialPressureReadCtr = 0;
     lastVenousPressureReadCtr   = 0;
@@ -665,13 +668,19 @@
     if ( getSoftwareConfigStatus( SW_CONFIG_DISABLE_PRESSURE_CHECKS ) != SW_CONFIG_ENABLE_VALUE )
 #endif
     {
-        // Range check occlusion sensor
+        F32 venPres = getMeasuredVenousPressure();
+        HD_OP_MODE_T hdMode = getCurrentOperationMode();
+        U32 hdSubMode = getCurrentSubMode();
+        BOOL txMode = ( MODE_TREA == hdMode ? TRUE : FALSE );
+        BOOL ptxMode = ( MODE_PRET == hdMode && hdSubMode > HD_PRE_TREATMENT_CART_INSTALL_STATE ? TRUE : FALSE );
+
+        // Range check occlusion sensor (OB)
         if ( TRUE == isPersistentAlarmTriggered( ALARM_ID_HD_BP_OCCLUSION_OUT_OF_RANGE, outOfRange ) )
         {
             SET_ALARM_WITH_1_U32_DATA( ALARM_ID_HD_BP_OCCLUSION_OUT_OF_RANGE, bpOccl );
         }
 
-        // Check for occlusion
+        // Check for BP occlusion
         if ( bpOccl > ( OCCLUSION_THRESHOLD_OFFSET + bloodPumpOcclusionAfterCartridgeInstall ) )
         {
             signalBloodPumpHardStop();  // Stop pump immediately
@@ -681,6 +690,20 @@
         {
             clearAlarmCondition( ALARM_ID_OCCLUSION_BLOOD_PUMP );
         }
+
+        // Check for venous occlusion
+        if ( ( TRUE == txMode || TRUE == ptxMode ) && ( venPres > getS32TreatmentParamUpperRangeLimit( TREATMENT_PARAM_VEN_PRESSURE_HIGH_LIMIT ) + VENOUS_PRESSURE_OCCL_OFFSET_MMHG ) )
+        {
+            if ( TRUE == isPersistentAlarmTriggered( ALARM_ID_HD_VENOUS_LINE_OCCLUSION, TRUE ) )
+            {
+                SET_ALARM_WITH_1_F32_DATA( ALARM_ID_HD_VENOUS_LINE_OCCLUSION, venPres );
+            }
+        }
+        else
+        {
+            clearAlarmCondition( ALARM_ID_HD_VENOUS_LINE_OCCLUSION );
+            isPersistentAlarmTriggered( ALARM_ID_HD_VENOUS_LINE_OCCLUSION, FALSE );
+        }
     }
 }
 
Index: firmware/App/Modes/OperationModes.c
===================================================================
diff -u -r45627442c3b93ec57ed18cd0943eed2662fb2dbc -raceb6e5388e905d119c5c379bc97ced0720aa270
--- firmware/App/Modes/OperationModes.c	(.../OperationModes.c)	(revision 45627442c3b93ec57ed18cd0943eed2662fb2dbc)
+++ firmware/App/Modes/OperationModes.c	(.../OperationModes.c)	(revision aceb6e5388e905d119c5c379bc97ced0720aa270)
@@ -253,6 +253,18 @@
 
 /*********************************************************************//**
  * @brief
+ * The getCurrentSubMode function gets the current operation sub-mode.
+ * @details Inputs: currentSubMode
+ * @details Outputs: none
+ * @return the current operation sub-mode
+ *************************************************************************/
+U32 getCurrentSubMode( void )
+{
+    return currentSubMode;
+}
+
+/*********************************************************************//**
+ * @brief
  * The initiateAlarmAction function initiate an alarm or alarm recovery
  * action according to the current operation mode.
  * @details Inputs: currentMode
Index: firmware/App/Modes/OperationModes.h
===================================================================
diff -u -r24b2fe72608344e67ef37234085d15ad5e4fcc37 -raceb6e5388e905d119c5c379bc97ced0720aa270
--- firmware/App/Modes/OperationModes.h	(.../OperationModes.h)	(revision 24b2fe72608344e67ef37234085d15ad5e4fcc37)
+++ firmware/App/Modes/OperationModes.h	(.../OperationModes.h)	(revision aceb6e5388e905d119c5c379bc97ced0720aa270)
@@ -45,6 +45,7 @@
 void requestNewOperationMode( HD_OP_MODE_T newMode );               // Request a transition to a new operation mode
 HD_OP_MODE_T getCurrentOperationMode( void );                       // Get the current operation mode
 HD_OP_MODE_T getPreviousOperationMode( void );                      // Get the previous operation mode
+U32  getCurrentSubMode( void );                                     // Get the current sub-mode
 void initiateAlarmAction( ALARM_ACTION_T action );                  // Initiate an alarm or alarm recovery action according to current op mode
 
 BOOL testSetOperationMode( HD_OP_MODE_T newMode );                  // Force transition to a given mode (if allowed)
Index: firmware/App/Modes/Prime.c
===================================================================
diff -u -rd4a4438fece666d728dc9825157af6ca99be8eb9 -raceb6e5388e905d119c5c379bc97ced0720aa270
--- firmware/App/Modes/Prime.c	(.../Prime.c)	(revision d4a4438fece666d728dc9825157af6ca99be8eb9)
+++ firmware/App/Modes/Prime.c	(.../Prime.c)	(revision aceb6e5388e905d119c5c379bc97ced0720aa270)
@@ -87,7 +87,7 @@
       { 120, 257 },                                             // DIALYZER_TYPE_BBRAUN_PRO_19H
       {  87, 233 },                                             // DIALYZER_TYPE_FRESENIUS_OPTIFLUX_F160NRE
       { 102, 280 },                                             // DIALYZER_TYPE_FRESENIUS_OPTIFLUX_F180NRE
-      { 113, 300 } };                                           // DIALYZER_TYPE_FRESENIUS_OPTIFLUX_F200NRE
+      { 113, 348 } };                                           // DIALYZER_TYPE_FRESENIUS_OPTIFLUX_F200NRE
 
 static U32 primeDialysateDialyzerTimeLimit;                     ///< Time limit in msec for priming dialysate dialyzer path.
 static U32 primeSalineDialyzerTimeLimit;                        ///< Time limit in msec for priming saline dialyzer path.