Index: firmware/App/Controllers/DialInFlow.c
===================================================================
diff -u -r326e3597e1555ef2ac4978f58786e7ce638b1287 -rc05775820109b5e83596c58a3b4248ac6cdb1d65
--- firmware/App/Controllers/DialInFlow.c	(.../DialInFlow.c)	(revision 326e3597e1555ef2ac4978f58786e7ce638b1287)
+++ firmware/App/Controllers/DialInFlow.c	(.../DialInFlow.c)	(revision c05775820109b5e83596c58a3b4248ac6cdb1d65)
@@ -116,6 +116,8 @@
 #define DIALYSATE_FLOW_FAST_READ_TO_PERSIST  100
 /// Dialysate flow slow read timeout alarm persistence.
 #define DIALYSATE_FLOW_SLOW_READ_TO_PERSIST  ( MS_PER_SECOND * 3 )
+/// Blood flow comm error persistence.
+#define DIALYSATE_FLOW_COMM_ERROR_PERSIST    MS_PER_SECOND
 
 #define DFM_SENSOR_CONNECTED_STATUS          0x00            ///< Dialysate flow meter connected status.
 #define DFM_SENSOR_PARAM_CORRUPT_STATUS      0x07            ///< Dialysate flow meter NVM parameter corrupt status.
@@ -190,16 +192,17 @@
 static U32 errorDialInRotorSpeedPersistTimerCtr = 0;                                ///< Persistence timer counter for rotor speed error condition.
 static U32 errorDialInPumpDirectionPersistTimerCtr = 0;                             ///< Persistence timer counter for pump direction error condition.
 
-static F32 flowReadings[ SIZE_OF_ROLLING_AVG ];                                     ///< Holds flow samples for a rolling average
-static U32 flowReadingsIdx = 0;                                                     ///< Index for next sample in rolling average array
-static F32 flowReadingsTotal = 0.0;                                                 ///< Rolling total - used to calc average
-static U32 flowReadingsCount = 0;                                                   ///< Number of samples in flow rolling average buffer
+static F32 flowReadings[ SIZE_OF_ROLLING_AVG ];                                     ///< Holds flow samples for a rolling average.
+static U32 flowReadingsIdx = 0;                                                     ///< Index for next sample in rolling average array.
+static F32 flowReadingsTotal = 0.0;                                                 ///< Rolling total - used to calc average.
+static U32 flowReadingsCount = 0;                                                   ///< Number of samples in flow rolling average buffer.
 
-static U32 dipCurrErrorDurationCtr = 0;                                             ///< Used for tracking persistence of dip current errors
+static U32 dipCurrErrorDurationCtr = 0;                                             ///< Used for tracking persistence of dip current errors.
 
-static U08 lastDialysateFlowFastPacketReadCtr = 0;                                  ///< Previous read counter for the dialysate flow fast packets
-static U08 lastDialysateFlowSlowPacketReadCtr = 0;                                  ///< Previous read counter for the dialysate flow slow packets
-static U08 lastDialInPumpDirectionCount = 0;                                        ///< Previous pump direction error count reported by FPGA
+static U08 lastDialysateFlowFastPacketReadCtr = 0;                                  ///< Previous read counter for the dialysate flow fast packets.
+static U08 lastDialysateFlowSlowPacketReadCtr = 0;                                  ///< Previous read counter for the dialysate flow slow packets.
+static U08 lastDialInPumpDirectionCount = 0;                                        ///< Previous pump direction error count reported by FPGA.
+static U08 lastDialysateFlowCommErrorCount = 0;                                     ///< Previous DPi flow sensor comm error count.
 
 // ********** private function prototypes **********
 
@@ -256,6 +259,7 @@
     initPersistentAlarm( ALARM_ID_DIALYSATE_FLOW_SIGNAL_STRENGTH_TOO_LOW, FLOW_SIG_STRGTH_ALARM_PERSIST, FLOW_SIG_STRGTH_ALARM_PERSIST );
     initPersistentAlarm( ALARM_ID_HD_DP_FLOW_READ_TIMEOUT_ERROR, 0, DIALYSATE_FLOW_FAST_READ_TO_PERSIST );
     initPersistentAlarm( ALARM_ID_HD_DP_FLOW_SLOW_READ_TIMEOUT_ERROR, 0, DIALYSATE_FLOW_SLOW_READ_TO_PERSIST );
+    initPersistentAlarm( ALARM_ID_HD_DP_FLOW_SENSOR_ERROR, 0, DIALYSATE_FLOW_COMM_ERROR_PERSIST );
 }
 
 /*********************************************************************//**
@@ -421,10 +425,15 @@
     U08 flowStatus = getFPGADialysateFlowMeterStatus();
 
 #ifndef DISABLE_PUMP_FLOW_CHECKS
+    if ( TRUE == isPersistentAlarmTriggered( ALARM_ID_HD_DP_FLOW_SENSOR_ERROR, ( flowErrorCtr != lastDialysateFlowCommErrorCount ) ) )
+    {
+        activateAlarmNoData( ALARM_ID_HD_DP_FLOW_SENSOR_ERROR );
+    }
     if ( flowStatus != DFM_SENSOR_CONNECTED_STATUS )
     {
         SET_ALARM_WITH_1_U32_DATA( ALARM_ID_HD_DIALYSATE_FLOW_STATUS_SELF_TEST_FAILURE, (U32)flowStatus );
     }
+    lastDialysateFlowCommErrorCount = flowErrorCtr;
 #endif
 
 #ifndef DISABLE_FPGA_COUNTER_CHECKS
@@ -471,7 +480,6 @@
     // Publish dialIn flow data on interval
     publishDialInFlowData();
 }
-//ALARM_ID_HD_DP_FLOW_SENSOR_ERROR = 210,                         ///< HD dialysate flow sensor error
 
 /*********************************************************************//**
  * @brief