Index: firmware/App/Drivers/SafetyShutdown.c
===================================================================
diff -u -r19ddae332910253204721af6204594467096f468 -r7d4711edd7b40cd3e29f43e766f79a8a09586fe9
--- firmware/App/Drivers/SafetyShutdown.c	(.../SafetyShutdown.c)	(revision 19ddae332910253204721af6204594467096f468)
+++ firmware/App/Drivers/SafetyShutdown.c	(.../SafetyShutdown.c)	(revision 7d4711edd7b40cd3e29f43e766f79a8a09586fe9)
@@ -1,14 +1,14 @@
 /**************************************************************************
 *
-* Copyright (c) 2019-2023 Diality Inc. - All Rights Reserved.
+* Copyright (c) 2019-2024 Diality Inc. - All Rights Reserved.
 *
 * THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
 * WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
 *
 * @file    SafetyShutdown.c
 *
-* @author  (last)      Dara Navaei
-* @date    (last)      14-Oct-2022
+* @author  (last)      Vinayakam Mani
+* @date    (last)      03-Oct-2023
 *
 * @author  (original)  Dara Navaei
 * @date    (original)  05-Nov-2019
@@ -36,8 +36,9 @@
 #define SAFETY_SHUTDOWN_POST_TIMEOUT_MS     500                                     ///< Safety shutdown POST test timeout (in ms).
 #define SAFETY_SHUTDOWN_RECOVERY_TIME_MS    500                                     ///< After safety shutdown POST test, wait this long (in ms) to recover before moving on.
 
-#define MAX_24V_LEVEL_ON_SAFETY_SHUTDOWN    5.0F                                    ///< Maximum voltage on 24V line when safety shutdown asserted.
-#define MIN_24V_LEVEL_ON_SAFETY_RECOVER     22.6F                                   ///< Minimum voltage on 24V line when safety shutdown is recovered.
+#define MAX_24V_LEVEL_ON_SAFETY_SHUTDOWN     5.0F                                   ///< Maximum voltage on 24V line when safety shutdown asserted.
+#define MAX_ISOLATED_24V_LEVEL_ON_SS_EXPIRED 22.6F                                  ///< Maximum voltage on isolated 24V line when watchdog is expired. 10% of 24V.
+#define MIN_24V_LEVEL_ON_SAFETY_RECOVER      22.6F                                  ///< Minimum voltage on 24V line when safety shutdown is recovered.
 
 /// Enumeration of safety shutdown self-test states.
 typedef enum Safety_Shutdown_Self_Test_States
@@ -73,7 +74,7 @@
     safetyShutdownSelfTestState      = SAFETY_SHUTDOWN_SELF_TEST_STATE_START;
     safetyShutdownSelfTestStatus     = SELF_TEST_STATUS_IN_PROGRESS;
     safetyShutdownSelfTestTimerCount = 0;
-    CLR_SAFETY_SHUTDOWN();
+    CLR_SAFETY_SHUTDOWN();
 }
 
 /*********************************************************************//**
@@ -126,10 +127,11 @@
         case SAFETY_SHUTDOWN_SELF_TEST_STATE_IN_PROGRESS:
             if ( TRUE == didTimeout( safetyShutdownSelfTestTimerCount, SAFETY_SHUTDOWN_POST_TIMEOUT_MS ) )
             {
-                F32 v24 = getIntADCVoltageConverted( INT_ADC_SECONDARY_HEATER_24_VOLTS );
+                F32 v24         = getIntADCVoltageConverted( INT_ADC_SECONDARY_HEATER_24_VOLTS );
+                F32 isolatedV24 = getRawIsolatedPowerSupplyVoltage();
 
                 // Verify 24V is down when w.d. expired
-                if ( v24 > MAX_24V_LEVEL_ON_SAFETY_SHUTDOWN )
+                if ( ( v24 > MAX_24V_LEVEL_ON_SAFETY_SHUTDOWN ) || ( isolatedV24 > MAX_ISOLATED_24V_LEVEL_ON_SS_EXPIRED ) )
                 {
                     SET_ALARM_WITH_2_F32_DATA( ALARM_ID_DG_SAFETY_SHUTDOWN_POST_TEST_FAILED, 1.0, v24 );
                     safetyShutdownSelfTestStatus = SELF_TEST_STATUS_FAILED;
@@ -144,11 +146,13 @@
         case SAFETY_SHUTDOWN_SELF_TEST_STATE_RECOVER:
             if ( TRUE == didTimeout( safetyShutdownSelfTestTimerCount, SAFETY_SHUTDOWN_RECOVERY_TIME_MS ) )
             {
-                F32 v24 = getIntADCVoltageConverted( INT_ADC_SECONDARY_HEATER_24_VOLTS );
+                F32 v24         = getIntADCVoltageConverted( INT_ADC_SECONDARY_HEATER_24_VOLTS );
+                F32 isolatedV24 = getRawIsolatedPowerSupplyVoltage();
 
                 // Verify 24V is down when w.d. recovered
-                if ( v24 < MIN_24V_LEVEL_ON_SAFETY_RECOVER )   // TODO - If issue persisted talk with systems why 24V does not recover fully.
+                if ( ( v24 < MIN_24V_LEVEL_ON_SAFETY_RECOVER ) || ( isolatedV24 < MAX_ISOLATED_24V_LEVEL_ON_SS_EXPIRED ) )
                 {
+                    // TODO - If issue persisted talk with systems why 24V does not recover fully.
                     SET_ALARM_WITH_2_F32_DATA( ALARM_ID_DG_SAFETY_SHUTDOWN_POST_TEST_FAILED, 2.0, v24 );
                     safetyShutdownSelfTestStatus = SELF_TEST_STATUS_FAILED;
                 }