Index: firmware/App/Controllers/PresOccl.c
===================================================================
diff -u -rd27dcf1fbbc9651636f211028917a1c0702bb56a -r7611b3a8e323b688441c88f56aa114d292efd4e1
--- firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision d27dcf1fbbc9651636f211028917a1c0702bb56a)
+++ firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision 7611b3a8e323b688441c88f56aa114d292efd4e1)
@@ -113,10 +113,11 @@
 
 static U32 emptySalineBagCtr = 0;                                               ///< Timer counter for empty bag detection.
 
-static U08 lastVenousPressureReadCtr;                                           ///< Previous venous pressure read count.
-static U08 lastBPOcclReadCtr;                                                   ///< Previous BP occlusion read count.
-static U08 lastDPiOcclReadCtr;                                                  ///< Previous DPi occlusion read count.
-static U08 lastDPoOcclReadCtr;                                                  ///< Previous DPo occlusion read count.
+static U08 lastArterialPressureReadCtr;                                         ///< Previous arterial pressure sensor read count.
+static U08 lastVenousPressureReadCtr;                                           ///< Previous venous pressure sensor read count.
+static U08 lastBPOcclReadCtr;                                                   ///< Previous BP occlusion sensor read count.
+static U08 lastDPiOcclReadCtr;                                                  ///< Previous DPi occlusion sensor read count.
+static U08 lastDPoOcclReadCtr;                                                  ///< Previous DPo occlusion sensor read count.
 static U08 lastBPErrorCtr;                                                      ///< Previous BP error count.
 static U08 lastDPIErrorCtr;                                                     ///< Previous DPi error count.
 static U08 lastDPOErrorCtr;                                                     ///< Previous DPo error count.
@@ -146,6 +147,7 @@
     initPersistentAlarm( ALARM_ID_ARTERIAL_PRESSURE_HIGH, PRES_ALARM_PERSISTENCE, PRES_ALARM_PERSISTENCE );
     initPersistentAlarm( ALARM_ID_VENOUS_PRESSURE_LOW, PRES_ALARM_PERSISTENCE, PRES_ALARM_PERSISTENCE );
     initPersistentAlarm( ALARM_ID_VENOUS_PRESSURE_HIGH, PRES_ALARM_PERSISTENCE, PRES_ALARM_PERSISTENCE );
+    initPersistentAlarm( ALARM_ID_HD_ARTERIAL_PRESSURE_READ_TIMEOUT_ERROR, 0, PRES_ALARM_PERSISTENCE );
     initPersistentAlarm( ALARM_ID_HD_VENOUS_PRESSURE_READ_TIMEOUT_ERROR, 0, PRES_ALARM_PERSISTENCE );
     initPersistentAlarm( ALARM_ID_HD_VENOUS_PRESSURE_SENSOR_TEMP_OUT_OF_RANGE, 0, PRES_ALARM_PERSISTENCE );
     initPersistentAlarm( ALARM_ID_HD_BP_OCCLUSION_READ_TIMEOUT_ERROR, 0, PRES_ALARM_PERSISTENCE );
@@ -160,6 +162,7 @@
     initPersistentAlarm( ALARM_ID_HD_DPI_OCCLUSION_OUT_OF_RANGE, 0, PRES_ALARM_PERSISTENCE );
     initPersistentAlarm( ALARM_ID_HD_DPO_OCCLUSION_OUT_OF_RANGE, 0, PRES_ALARM_PERSISTENCE );
 
+    lastArterialPressureReadCtr = 0;
     lastVenousPressureReadCtr = 0;
     lastBPOcclReadCtr = 0;
     lastDPiOcclReadCtr = 0;
@@ -341,7 +344,20 @@
     // Convert arterial pressure to mmHg if no fault
     if ( 0 == artPresAlarm )
     {
-        arterialPressure.data = ARTERIAL_PRESSURE_V_PER_BIT * ( (F32)(artPres) / ( ARTERIAL_PRESSURE_SENSITIVITY * ARTERIAL_PRESSURE_V_BIAS ) );
+        U08 artReadCtr = getFPGAArterialPressureReadCounter();
+        U08 artErrorCtr = getFPGAArterialPressureErrorCounter();
+
+        // Check for stale arterial pressure reading
+        if ( FALSE == isPersistentAlarmTriggered( ALARM_ID_HD_VENOUS_PRESSURE_READ_TIMEOUT_ERROR, ( lastArterialPressureReadCtr == artReadCtr || artErrorCtr > 0 ) ) )
+        {
+            arterialPressure.data = ARTERIAL_PRESSURE_V_PER_BIT * ( (F32)(artPres) / ( ARTERIAL_PRESSURE_SENSITIVITY * ARTERIAL_PRESSURE_V_BIAS ) );
+        }
+        else
+        {
+            SET_ALARM_WITH_1_U32_DATA( ALARM_ID_HD_ARTERIAL_PRESSURE_READ_TIMEOUT_ERROR, (U32)artErrorCtr );
+        }
+        // Record arterial pressure sensor read counter for next time around
+        lastArterialPressureReadCtr = artReadCtr;
     }
     else
     {
@@ -355,7 +371,7 @@
     {
         activateAlarmNoData( ALARM_ID_HD_VENOUS_PRESSURE_READ_TIMEOUT_ERROR );
     }
-    // Record venous read counter for next time around
+    // Record venous pressure sensor read counter for next time around
     lastVenousPressureReadCtr = venReadCtr;
     // Convert venous pressure to PSI and then mmHg
     venPresPSI = ( (F32)(venPres - VENOUS_PRESSURE_OFFSET) * (VENOUS_PRESSURE_MAX_PSI - VENOUS_PRESSURE_MIN_PSI) / (F32)VENOUS_PRESSURE_SCALE ) + VENOUS_PRESSURE_MIN_PSI;
@@ -454,8 +470,8 @@
 
 #ifndef DISABLE_PRESSURE_CHECKS
     // Check arterial pressure is in range
-    if ( TRUE == isPersistentAlarmTriggered( ALARM_ID_HD_ARTERIAL_PRESSURE_OUT_OF_RANGE, artPres > ARTERIAL_PRESSURE_MAX_MMHG ) ||
-         TRUE == isPersistentAlarmTriggered( ALARM_ID_HD_ARTERIAL_PRESSURE_OUT_OF_RANGE, artPres < ARTERIAL_PRESSURE_MIN_MMHG ) )
+    if ( TRUE == isPersistentAlarmTriggered( ALARM_ID_HD_ARTERIAL_PRESSURE_OUT_OF_RANGE,
+                                             ( artPres > ARTERIAL_PRESSURE_MAX_MMHG || artPres < ARTERIAL_PRESSURE_MIN_MMHG ) ) )
     {
         SET_ALARM_WITH_1_F32_DATA( ALARM_ID_HD_ARTERIAL_PRESSURE_OUT_OF_RANGE, artPres );
     }