Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -r4d637d588c0d78d95645e24ccbfdc01d45718a2f -rd5f2ac4d84453feb1b782f35f9d69432977a95f6
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 4d637d588c0d78d95645e24ccbfdc01d45718a2f)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision d5f2ac4d84453feb1b782f35f9d69432977a95f6)
@@ -7,8 +7,8 @@
 *
 * @file    SystemCommMessages.c
 *
-* @author  (last)      Dara Navaei
-* @date    (last)      21-Jun-2022
+* @author  (last)      Michael Garthwaite
+* @date    (last)      07-Sep-2022
 *
 * @author  (original)  Dara Navaei
 * @date    (original)  05-Nov-2019
@@ -1393,6 +1393,56 @@
 
 /*********************************************************************//**
  * @brief
+ * The handleTestSetOpModeRequest function handles a request to set the
+ * DG operation mode.
+ * @details Inputs: none
+ * @details Outputs: message handled
+ * @param message a pointer to the message to handle
+ * @return none
+ *************************************************************************/
+void handleTestSetOpModeRequest( MESSAGE_T *message )
+{
+    BOOL result = FALSE;
+
+    if ( message->hdr.payloadLen == sizeof(U32) )
+    {
+        U32 mode;
+
+        memcpy( &mode, message->payload, sizeof(U32) );
+        result = testSetOperationMode( (DG_OP_MODE_T)mode );
+    }
+
+    // Respond to request
+    sendTestAckResponseMsg( (MSG_ID_T)message->hdr.msgID, result );
+}
+
+/*********************************************************************//**
+ * @brief
+ * The handleTestTareReservoirRequest function handles a request to tare a
+ * given reservoir's weight.
+ * @details Inputs: none
+ * @details Outputs: message handled
+ * @param message a pointer to the message to handle
+ * @return none
+ *************************************************************************/
+void handleTestTareReservoirRequest( MESSAGE_T *message )
+{
+    BOOL result = FALSE;
+
+    if ( message->hdr.payloadLen == sizeof(U32) )
+    {
+        U32 res;
+
+        memcpy( &res, message->payload, sizeof(U32) );
+        result = testTareReservoir( res );
+    }
+
+    // Respond to request
+    sendTestAckResponseMsg( (MSG_ID_T)message->hdr.msgID, result );
+}
+
+/*********************************************************************//**
+ * @brief
  * The handleSetHDOperationMode function receives the HD operation modes data
  * publish message.
  * @details Inputs: none
@@ -3692,4 +3742,73 @@
     sendTestAckResponseMsg( (MSG_ID_T)message->hdr.msgID, result );
 }
 
+/*********************************************************************//**
+* @brief
+* The handleServiceModeRequest function handles a request to enter service
+* mode.
+* @details Inputs: none
+* @details Outputs: message handled
+* @param message a pointer to the message to handle
+* @return none
+*************************************************************************/
+void handleServiceModeRequest( MESSAGE_T *message )
+{
+    BOOL status = FALSE;
+    DG_OP_MODE_T currentMode = getCurrentOperationMode();
+    REQUEST_REJECT_REASON_CODE_T reject;
+
+    if ( 0 == message->hdr.payloadLen )
+    {
+        if ( ( DG_MODE_STAN == currentMode ) || ( DG_MODE_FAUL == currentMode ) )
+        {
+            status = TRUE;
+            requestNewOperationMode( DG_MODE_SERV );
+            reject = REQUEST_REJECT_REASON_NONE;
+        }
+        else
+        {
+            reject = REQUEST_REJECT_REASON_DG_NOT_IN_STANDBY_IDLE_STATE;
+        }
+    }
+    else
+    {
+        reject = REQUEST_REJECT_REASON_INVALID_REQUEST_FORMAT;
+    }
+
+    // Respond to request
+    sendTestAckResponseMsg( (MSG_ID_T)message->hdr.msgID, status );
+    sendServiceModeResponse( status, (U32)reject );
+}
+
+/*********************************************************************//**
+ * @brief
+ * The sendServiceModeResponse function sends out the DG response to a
+ * UI request to go to service mode.
+ * @details Inputs: none
+ * @details Outputs: Service mode request response msg constructed and queued
+ * @param accepted TRUE if request was accepted, FALSE if not
+ * @param rejCode Reject reason code explaining why request was rejected
+ * @return none
+ *************************************************************************/
+BOOL sendServiceModeResponse( BOOL accepted, U32 rejCode )
+{
+    BOOL result;
+    MESSAGE_T msg;
+    U08 *payloadPtr = msg.payload;
+
+    // Create a message record
+    blankMessage( &msg );
+    msg.hdr.msgID = MSG_ID_DG_RESPONSE_SERVICE_MODE_REQUEST;
+    msg.hdr.payloadLen = sizeof( BOOL ) + sizeof( U32 );
+
+    memcpy( payloadPtr, &accepted, sizeof( BOOL ) );
+    payloadPtr += sizeof( BOOL );
+    memcpy( payloadPtr, &rejCode, sizeof( U32 ) );
+
+    // Serialize the message (w/ sync, CRC, and appropriate CAN padding) and add serialized message data to appropriate comm buffer
+    result = serializeMessage( msg, COMM_BUFFER_OUT_CAN_DG_2_HD, ACK_REQUIRED );
+
+    return result;
+}
+
 /**@}*/