Index: firmware/App/Controllers/DialInFlow.c
===================================================================
diff -u -r6fcdec8a308be986e5a64b4222918e718622a19d -r794f0aea88a5a860448e54e99db6e2e881b22900
--- firmware/App/Controllers/DialInFlow.c	(.../DialInFlow.c)	(revision 6fcdec8a308be986e5a64b4222918e718622a19d)
+++ firmware/App/Controllers/DialInFlow.c	(.../DialInFlow.c)	(revision 794f0aea88a5a860448e54e99db6e2e881b22900)
@@ -112,6 +112,9 @@
 #define FLOW_SIG_STRGTH_ALARM_PERSIST        ( 5 * MS_PER_SECOND )
 #define MIN_FLOW_SIG_STRENGTH                0.9             ///< Minimum flow sensor signal strength (90%).
 
+/// Dialysate flow read timeout alarm persistence.
+#define DIALYSATE_FLOW_READ_TIMEOUT_PERSIST  ( MS_PER_SECOND )
+
 #define DFM_SENSOR_PARAM_CORRUPT_STATUS      0x7             ///< Dialysate flow meter NVM parameter corrupt status.
 
 /// Enumeration of dialysate inlet pump states.
@@ -133,6 +136,15 @@
     NUM_OF_DIAL_IN_FLOW_SELF_TEST_STATES        ///< Number of dialysate inlet pump self-test states.
 } DIAL_IN_FLOW_SELF_TEST_STATE_T;
 
+/// Enumeration of dialysate flow read counters.
+typedef enum DialysateFlow_Read_Counters
+{
+    DIALYSATE_FLOW_READ_CTR_FAST_PACKET = 0,    ///< Dialysate flow fast packet read counter
+    DIALYSATE_FLOW_READ_CTR_SLOW_PACKET,        ///< Dialysate flow slow packet read counter
+    DIALYSATE_FLOW_READ_CTR_STATUS_PACKET,      ///< Dialysate flow status packet read counter
+    NUM_OF_DIALYSATE_FLOW_READ_COUNTERS         ///< Number of dialysate flow read counters.
+} DIALYSATE_FLOW_READ_COUNTER_T;
+
 // Pin assignments for pump stop and direction outputs
 #define STOP_DI_PUMP_GIO_PORT_PIN        2U             ///< Pin # on GIO A for stopping the dialysate inlet pump.
 #define DIR_DI_PUMP_SPI5_PORT_MASK       0x00000100     ///< Pin on unused SPI5 peripheral (ENA) - re-purposed as output GPIO to set dialysate inlet pump direction.
@@ -189,6 +201,10 @@
 
 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 lastDialysateFlowStatusPacketReadCtr = 0;                                ///< Previous read counter for the dialysate flow status packets
+
 // ********** private function prototypes **********
 
 static DIAL_IN_PUMP_STATE_T handleDialInPumpOffState( void );
@@ -242,6 +258,7 @@
 
     // Initialize persistent alarm for flow sensor signal strength too low
     initPersistentAlarm( ALARM_ID_DIALYSATE_FLOW_SIGNAL_STRENGTH_TOO_LOW, FLOW_SIG_STRGTH_ALARM_PERSIST, FLOW_SIG_STRGTH_ALARM_PERSIST );
+    initPersistentAlarm( ALARM_ID_HD_BP_FLOW_READ_TIMEOUT_ERROR, 0, DIALYSATE_FLOW_READ_TIMEOUT_PERSIST );
 }
 
 /*********************************************************************//**
@@ -400,7 +417,30 @@
     HD_OP_MODE_T opMode = getCurrentOperationMode();
     U16 dipRPM = getIntADCReading( INT_ADC_DIAL_IN_PUMP_SPEED );
     U16 dipmA = getIntADCReading( INT_ADC_DIAL_IN_PUMP_MOTOR_CURRENT );
-    F32 dipFlow = ( getFPGADialysateFlow() * dialInFlowCalGain ) + dialInFlowCalOffset;
+    F32 dipFlow = ( getFPGADialysateFlow() * dialInFlowCalGain ) + dialInFlowCalOffset;
+    U08 fpReadCtr = getFPGADialysateFlowFastPacketReadCounter();
+    U08 spReadCtr = getFPGADialysateFlowSlowPacketReadCounter();
+    U08 stpReadCtr = getFPGADialysateFlowStatusPacketReadCounter();
+    U08 flowErrorCtr = getFPGADialysateFlowErrorCounter();
+
+    // Check for stale flow reading
+    if ( TRUE == isPersistentAlarmTriggered( ALARM_ID_HD_DP_FLOW_READ_TIMEOUT_ERROR, ( fpReadCtr == lastDialysateFlowFastPacketReadCtr ) ) )
+    {
+        SET_ALARM_WITH_1_U32_DATA( ALARM_ID_HD_DP_FLOW_READ_TIMEOUT_ERROR, (U32)DIALYSATE_FLOW_READ_CTR_FAST_PACKET )
+    }
+    if ( TRUE == isPersistentAlarmTriggered( ALARM_ID_HD_DP_FLOW_READ_TIMEOUT_ERROR, ( spReadCtr == lastDialysateFlowSlowPacketReadCtr ) ) )
+    {
+        SET_ALARM_WITH_1_U32_DATA( ALARM_ID_HD_DP_FLOW_READ_TIMEOUT_ERROR, (U32)DIALYSATE_FLOW_READ_CTR_SLOW_PACKET )
+    }
+    if ( TRUE == isPersistentAlarmTriggered( ALARM_ID_HD_DP_FLOW_READ_TIMEOUT_ERROR, ( stpReadCtr == lastDialysateFlowStatusPacketReadCtr ) ) )
+    {
+        SET_ALARM_WITH_1_U32_DATA( ALARM_ID_HD_DP_FLOW_READ_TIMEOUT_ERROR, (U32)DIALYSATE_FLOW_READ_CTR_STATUS_PACKET )
+    }
+
+    // Record flow read counters for next time around
+    lastDialysateFlowFastPacketReadCtr = fpReadCtr;
+    lastDialysateFlowSlowPacketReadCtr = spReadCtr;
+    lastDialysateFlowStatusPacketReadCtr = stpReadCtr;
 
     adcDialInPumpMCSpeedRPM.data = (F32)(SIGN_FROM_12_BIT_VALUE(dipRPM)) * DIP_SPEED_ADC_TO_RPM_FACTOR;
     adcDialInPumpMCCurrentmA.data = (F32)(SIGN_FROM_12_BIT_VALUE(dipmA)) * DIP_CURRENT_ADC_TO_MA_FACTOR;
@@ -430,6 +470,7 @@
     // Publish dialIn flow data on interval
     publishDialInFlowData();
 }
+//ALARM_ID_HD_DP_FLOW_SENSOR_ERROR = 210,                         ///< HD dialysate flow sensor error
 
 /*********************************************************************//**
  * @brief
@@ -1235,7 +1276,7 @@
     // Get the flow sensors calibration record
     HD_FLOW_SENSORS_CAL_RECORD_T cal = getHDFlowSensorsCalibrationRecord();
 
-    if (  DFM_SENSOR_PARAM_CORRUPT_STATUS != dfmStatus )
+    if ( DFM_SENSOR_PARAM_CORRUPT_STATUS != dfmStatus )
     {
         dialInFlowCalGain   = cal.hdFlowSensors[ CAL_DATA_HD_DIALYZER_FLOW_SENSOR ].gain;
         dialInFlowCalOffset = cal.hdFlowSensors[ CAL_DATA_HD_DIALYZER_FLOW_SENSOR ].offset;