Index: firmware/App/Controllers/DGInterface.c
===================================================================
diff -u -r23c460cb679562d2bc55b1a60ce5c58db895752b -r0b0c51179b65caa058354dd491441956432654bc
--- firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision 23c460cb679562d2bc55b1a60ce5c58db895752b)
+++ firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision 0b0c51179b65caa058354dd491441956432654bc)
@@ -43,13 +43,15 @@
 
 #define SIZE_OF_LARGE_LOAD_CELL_AVG              32                         ///< Large load cell moving average has 32 samples.
 
-#define DIALYSATE_TEMP_OUT_OF_TARGET_TOL_C       4.0F                       ///< Dialysate temperature out of target tolerance C.
-#define DIALYSATE_TEMP_OUT_OF_TARGET_TIMEOUT_MS  ( 300 * MS_PER_SECOND )    ///< Dialysate temperature out of target timeout in milliseconds.
-#define DIALYSATE_TEMP_HIGH_SAFETY_LIMIT_C       46.0F                      ///< Dialysate high safety temperature limit in C.
-#define DIALYSATE_TEMP_HIGH_SAFETY_TIMEOUT_MS    ( 1 * MS_PER_SECOND )      ///< Dialysate temperature high safety timeout in milliseconds.
-#define DIALYSATE_TEMP_LOW_SAFETY_LIMIT_C        42.0F                      ///< Dialysate low safety temperature limit in C.
-#define DIALYSATE_TEMP_LOW_SAFETY_TIMEOUT_MS     ( 10 * MS_PER_SECOND )     ///< Dialysate temperature low safety timeout in milliseconds.
-#define DG_DATA_FRESHNESS_TIMEOUT_MS             ( 3 * MS_PER_SECOND )      ///< DG data freshness timeout (in ms).
+#define DIALYSATE_TEMP_OUT_OF_TARGET_TOL_C              4.0F                        ///< Dialysate temperature out of target tolerance C.
+#define DIALYSATE_TEMP_OUT_OF_TARGET_TIMEOUT_MS         ( 300 * MS_PER_SECOND )     ///< Dialysate temperature out of target timeout in milliseconds.
+#define DIALYSATE_TEMP_UPPER_MAX_SAFETY_LIMIT_C         46.0F                       ///< Dialysate upper bound maximum temperature limit in C.
+#define DIALYSATE_TEMP_UPPER_MAX_SAFETY_TIMEOUT_MS      ( 1 * MS_PER_SECOND )       ///< Dialysate temperature upper bound maximum safety timeout in milliseconds.
+#define DIALYSATE_TEMP_UPPER_SAFETY_LIMIT_C             42.0F                       ///< Dialysate upper bound safety temperature limit in C.
+#define DIALYSATE_TEMP_UPPER_SAFETY_TIMEOUT_MS          ( 300 * MS_PER_SECOND )     ///< Dialysate temperature upper bound timeout in milliseconds.
+#define DIALYSATE_TEMP_LOWER_SAFETY_LIMIT_C             33.0F                       ///< Dialysate lower bound safety temperature limit in C.
+#define DIALYSATE_TEMP_LOWER_SAFETY_TIMEOUT_MS          ( 300 * MS_PER_SECOND )     ///< Dialysate temperature lower bound timeout in milliseconds.
+#define DG_DATA_FRESHNESS_TIMEOUT_MS                    ( 3 * MS_PER_SECOND )       ///< DG data freshness timeout (in ms).
 
 // ********** private data **********
 
@@ -170,9 +172,13 @@
     lgLoadCellBackupReadingsTotal[ DG_RESERVOIR_1 ] = 0.0F;
     lgLoadCellBackupReadingsTotal[ DG_RESERVOIR_2 ] = 0.0F;
 
-    initPersistentAlarm( ALARM_ID_HD_DIALYSATE_TEMP_OUT_OF_HIGH_SAFETY_RANGE, DIALYSATE_TEMP_HIGH_SAFETY_TIMEOUT_MS, DIALYSATE_TEMP_HIGH_SAFETY_TIMEOUT_MS );
-    initPersistentAlarm( ALARM_ID_HD_DIALYSATE_TEMP_OUT_OF_LOW_SAFETY_RANGE, DIALYSATE_TEMP_LOW_SAFETY_TIMEOUT_MS, DIALYSATE_TEMP_LOW_SAFETY_TIMEOUT_MS );
+    initPersistentAlarm( ALARM_ID_HD_DIALYSATE_TEMP_ABOVE_HIGH_SAFETY_RANGE, DIALYSATE_TEMP_UPPER_MAX_SAFETY_TIMEOUT_MS, DIALYSATE_TEMP_UPPER_MAX_SAFETY_TIMEOUT_MS );
+    initPersistentAlarm( ALARM_ID_HD_DIALYSATE_TEMP_ABOVE_LOW_SAFETY_RANGE, DIALYSATE_TEMP_UPPER_SAFETY_TIMEOUT_MS, DIALYSATE_TEMP_UPPER_SAFETY_TIMEOUT_MS );
+    initPersistentAlarm( ALARM_ID_HD_DIALYSATE_TEMP_BELOW_LOW_SAFETY_RANGE, DIALYSATE_TEMP_LOWER_SAFETY_TIMEOUT_MS, DIALYSATE_TEMP_LOWER_SAFETY_TIMEOUT_MS );
 
+    initPersistentAlarm( ALARM_ID_HD_DIALYSATE_TEMP_BELOW_TARGET_TEMP, DIALYSATE_TEMP_OUT_OF_TARGET_TIMEOUT_MS, DIALYSATE_TEMP_OUT_OF_TARGET_TIMEOUT_MS );
+    initPersistentAlarm( ALARM_ID_HD_DIALYSATE_TEMP_ABOVE_TARGET_TEMP, DIALYSATE_TEMP_OUT_OF_TARGET_TIMEOUT_MS, DIALYSATE_TEMP_OUT_OF_TARGET_TIMEOUT_MS );
+
     initPersistentAlarm( ALARM_ID_HD_NEW_LOAD_CELL_DATA_MESSAGE_NOT_RECEIVE, DG_DATA_FRESHNESS_TIMEOUT_MS, DG_DATA_FRESHNESS_TIMEOUT_MS );
     initPersistentAlarm( ALARM_ID_HD_NEW_DIALYSATE_TEMPERATURE_DATA_MESSAGE_NOT_RECEIVE, DG_DATA_FRESHNESS_TIMEOUT_MS, DG_DATA_FRESHNESS_TIMEOUT_MS );
     initPersistentAlarm( ALARM_ID_HD_NEW_RESERVOIRS_DATA_MESSAGE_NOT_RECEIVE, DG_DATA_FRESHNESS_TIMEOUT_MS, DG_DATA_FRESHNESS_TIMEOUT_MS );
@@ -1097,8 +1103,9 @@
  *************************************************************************/
 void checkDialysateTemperature( void )
 {
-    BOOL isTDiTempAboveHighSafety      = ( dgDialysateTemp >= DIALYSATE_TEMP_HIGH_SAFETY_LIMIT_C ? TRUE : FALSE );
-    BOOL isTDiTempAboveLowSafety       = ( dgDialysateTemp >= DIALYSATE_TEMP_LOW_SAFETY_LIMIT_C ? TRUE : FALSE );
+    BOOL isTDiTempAboveHighSafety      = ( dgDialysateTemp >= DIALYSATE_TEMP_UPPER_MAX_SAFETY_LIMIT_C ? TRUE : FALSE );
+    BOOL isTDiTempAboveLowSafety       = ( dgDialysateTemp >= DIALYSATE_TEMP_UPPER_SAFETY_LIMIT_C ? TRUE : FALSE );
+    BOOL isTDITempBelowLowSafety       = ( dgDialysateTemp <= DIALYSATE_TEMP_LOWER_SAFETY_LIMIT_C ? TRUE : FALSE );
     F32 TDiHigh                        = dgTrimmerTempSet + DIALYSATE_TEMP_OUT_OF_TARGET_TOL_C;
     BOOL isTDiTempAboveDialysateTarget = ( dgDialysateTemp >= TDiHigh ? TRUE : FALSE );
     F32 TDiLow                         = dgTrimmerTempSet - DIALYSATE_TEMP_OUT_OF_TARGET_TOL_C;
@@ -1108,31 +1115,10 @@
     if ( getSoftwareConfigStatus( SW_CONFIG_DISABLE_DIALYSATE_TEMP_CHECK ) != SW_CONFIG_ENABLE_VALUE )
 #endif
     {
-        checkPersistentAlarm( ALARM_ID_HD_DIALYSATE_TEMP_OUT_OF_HIGH_SAFETY_RANGE, isTDiTempAboveHighSafety, dgDialysateTemp, DIALYSATE_TEMP_HIGH_SAFETY_LIMIT_C );
-        checkPersistentAlarm( ALARM_ID_HD_DIALYSATE_TEMP_OUT_OF_LOW_SAFETY_RANGE,  isTDiTempAboveLowSafety,  dgDialysateTemp, DIALYSATE_TEMP_LOW_SAFETY_LIMIT_C );
-
-        // Per PRS 377
-        if ( TRUE == isTDiTempAboveDialysateTarget )
-        {
-            SET_ALARM_WITH_2_F32_DATA( ALARM_ID_HD_DIALYSATE_TEMP_ABOVE_TARGET_TEMP, dgDialysateTemp, TDiHigh );
-        }
-
-        else
-        {
-            clearAlarmCondition( ALARM_ID_HD_DIALYSATE_TEMP_ABOVE_TARGET_TEMP );
-        }
-
-        // Per PRS 124
-        if ( TRUE == isTDiTempBelowDialysateTarget )
-        {
-            SET_ALARM_WITH_2_F32_DATA( ALARM_ID_HD_DIALYSATE_TEMP_BELOW_TARGET_TEMP, dgDialysateTemp, TDiLow );
-        }
-
-        else
-        {
-            clearAlarmCondition( ALARM_ID_HD_DIALYSATE_TEMP_BELOW_TARGET_TEMP );
-        }
-
+        // Per PRS 377 & PRS 124
+        checkPersistentAlarm( ALARM_ID_HD_DIALYSATE_TEMP_ABOVE_HIGH_SAFETY_RANGE, isTDiTempAboveHighSafety, dgDialysateTemp, DIALYSATE_TEMP_UPPER_MAX_SAFETY_LIMIT_C );
+        checkPersistentAlarm( ALARM_ID_HD_DIALYSATE_TEMP_ABOVE_LOW_SAFETY_RANGE,  isTDiTempAboveLowSafety,  dgDialysateTemp, DIALYSATE_TEMP_UPPER_SAFETY_LIMIT_C );
+        checkPersistentAlarm( ALARM_ID_HD_DIALYSATE_TEMP_BELOW_LOW_SAFETY_RANGE,  isTDITempBelowLowSafety,  dgDialysateTemp, DIALYSATE_TEMP_LOWER_SAFETY_LIMIT_C );
     }
 }