Index: firmware/App/Modes/ModeService.c
===================================================================
diff -u -ra303cd4258157a8fbcbd8af4dd2bbaadec1a736c -r3b70632c04247a6973960e1f37ae73eb4384a6b7
--- firmware/App/Modes/ModeService.c	(.../ModeService.c)	(revision a303cd4258157a8fbcbd8af4dd2bbaadec1a736c)
+++ firmware/App/Modes/ModeService.c	(.../ModeService.c)	(revision 3b70632c04247a6973960e1f37ae73eb4384a6b7)
@@ -1,63 +1,98 @@
 /**************************************************************************
- *
- *  Copyright (c) 2019-2020 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 ModeService.c
- *
- *  @date 19-Sep-2019
- *  @author S. Nash
- *
- *  @brief Top-level state machine for the service mode.
- *
- **************************************************************************/
+*
+* Copyright (c) 2019-2022 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    ModeService.c
+*
+* @author  (last)      Michael Garthwaite
+* @date    (last)      07-Sep-2022
+*
+* @author  (original)  Dara Navaei
+* @date    (original)  05-Nov-2019
+*
+***************************************************************************/
 
-#include "Common.h"
 #include "OperationModes.h"
 #include "ModeService.h"
 
+/**
+ *  @addtogroup DGServiceMode
+ *  @{
+ */
+
+// ********** private definitions **********
+
 // ********** private data **********
 
+static DG_SERVICE_STATE_T serviceState = DG_SERVICE_STATE_START;       ///< Currently active service state.
+
 // ********** private function prototypes **********
 
-/*************************************************************************
- * @brief initServiceMode
- * The initServiceMode function initializes the Service Mode module.
- * @details
- * Inputs : none
- * Outputs : Service Mode module initialized.
- * @param none
+/*********************************************************************//**
+ * @brief
+ * The initServiceMode function initializes the service mode module.
+ * @details Inputs: none
+ * @details Outputs: Service mode module initialized
  * @return none
  *************************************************************************/
 void initServiceMode( void )
 {
+    serviceState = DG_SERVICE_STATE_START;
 }
 
-/*************************************************************************
- * @brief transitionToServiceMode
+/*********************************************************************//**
+ * @brief
  * The transitionToServiceMode function prepares for transition to service mode.
- * @details
- * Inputs : none
- * Outputs :
- * @param none
- * @return none
+ * @details Inputs: none
+ * @details Outputs: none
+ * @return initial state
  *************************************************************************/
-void transitionToServiceMode( void )
+U32 transitionToServiceMode( void )
 {
+    deenergizeActuators();
+
+    initServiceMode();
+
+    return serviceState;
 }
 
-/*************************************************************************
- * @brief execServiceMode
- * The execServiceMode function executes the Service Mode state machine.
- * @details
- * Inputs : none
- * Outputs :
- * @param none
- * @return none
+/*********************************************************************//**
+ * @brief
+ * The execServiceMode function executes the service mode state machine.
+ * @details Inputs: none
+ * @details Outputs: Service mode state machine executed
+ * @return current state.
  *************************************************************************/
-void execServiceMode( void )
+U32 execServiceMode( void )
 {
+    // execute current service state
+    switch ( serviceState )
+    {
+        case DG_SERVICE_STATE_START:
+            break;
+
+        default:
+            SET_ALARM_WITH_2_U32_DATA( ALARM_ID_DG_SOFTWARE_FAULT, SW_FAULT_ID_SERVICE_MODE_INVALID_EXEC_STATE, serviceState )
+            serviceState = DG_SERVICE_STATE_START;
+            break;
+    }
+
+    return serviceState;
 }
 
+/*********************************************************************//**
+ * @brief
+ * The getCurrentServiceState function returns the current state of the service mode.
+ * @details Inputs: serviceState
+ * @details Outputs: none
+ * @return the current state of service mode
+ *************************************************************************/
+DG_SERVICE_STATE_T getCurrentServiceState( void )
+{
+    return serviceState;
+}
+
+/**@}*/