Index: firmware/App/Services/SystemComm.h
===================================================================
diff -u -ref12a43be17c4f1ed13302f81ca616a483850483 -r7d4711edd7b40cd3e29f43e766f79a8a09586fe9
--- firmware/App/Services/SystemComm.h	(.../SystemComm.h)	(revision ef12a43be17c4f1ed13302f81ca616a483850483)
+++ firmware/App/Services/SystemComm.h	(.../SystemComm.h)	(revision 7d4711edd7b40cd3e29f43e766f79a8a09586fe9)
@@ -1,14 +1,14 @@
 /**************************************************************************
 *
-* Copyright (c) 2019-2021 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    SystemComm.h
 *
-* @author  (last)      Quang Nguyen
-* @date    (last)      24-Aug-2020
+* @author  (last)      Michael Garthwaite
+* @date    (last)      17-Aug-2023
 *
 * @author  (original)  Dara Navaei
 * @date    (original)  05-Nov-2019
@@ -32,17 +32,17 @@
 
 // ********** public definitions **********
 
-#define MESSAGE_SYNC_BYTE           0xA5                                                                ///< Denali message syncronization byte.
+#define MESSAGE_SYNC_BYTE                       0xA5                                                                ///< Denali message syncronization byte.
 
-#define CAN_MESSAGE_PAYLOAD_SIZE    8                                                                   ///< CAN frame payload size (in bytes).
+#define CAN_MESSAGE_PAYLOAD_SIZE                8                                                                   ///< CAN frame payload size (in bytes).
 
-#define MSG_ID_ACK                  0xFFFF                                                              ///< Denali message ID for acknowledging received messages (when required).
-#define MSG_ACK_BIT                 0x8000                                                              ///< ACK bit in sequence number that indicates an ACK is required.
-#define MAX_MSG_SEQ_NO              0x7FFF                                                              ///< Maximum sequence number for Denali message (then wraps to 1).
-#define MIN_MSG_SEQ_NO              0x0001                                                              ///< Minimum sequence number for Denali message.
-#define MAX_ACK_MSG_SIZE            ( sizeof( MESSAGE_WRAPPER_T ) + 1 + CAN_MESSAGE_PAYLOAD_SIZE )      ///< Maximum size (in bytes) of Denali message including full (wrapped) message + sync + any CAN padding)
+#define MSG_ID_ACK_MESSAGE_THAT_REQUIRES_ACK    0xFFFF                                                              ///< Denali message ID for acknowledging received messages (when required).
+#define MSG_ACK_BIT                             0x8000                                                              ///< ACK bit in sequence number that indicates an ACK is required.
+#define MAX_MSG_SEQ_NO                          0x7FFF                                                              ///< Maximum sequence number for Denali message (then wraps to 1).
+#define MIN_MSG_SEQ_NO                          0x0001                                                              ///< Minimum sequence number for Denali message.
+#define MAX_ACK_MSG_SIZE                        ( sizeof( MESSAGE_WRAPPER_T ) + 1 + CAN_MESSAGE_PAYLOAD_SIZE )      ///< Maximum size (in bytes) of Denali message including full (wrapped) message + sync + any CAN padding)
 
-typedef COMM_BUFFER_T   CAN_MESSAGE_BOX_T;                                                              ///< the CAN comm buffers align with the active CAN message boxes
+typedef COMM_BUFFER_T   CAN_MESSAGE_BOX_T;                                                                          ///< the CAN comm buffers align with the active CAN message boxes
 
 // ********** public function prototypes **********
 
@@ -55,6 +55,10 @@
 BOOL isHDCommunicating( void );
 BOOL isDGOnlyCANNode( void );
 BOOL addMsgToPendingACKList( MESSAGE_T *msg, COMM_BUFFER_T channel, U08 *msgData, U32 len );
+BOOL testSetHDCommunicationStatus( U32 value );
+BOOL testResetHDCommuncationStatus( void );
+BOOL testSetPendingACKOverride( U32 value );
+BOOL testResetPendingACKOverride( void );
 
 /**@}*/