Index: firmware/App/Services/SystemCommTD.h
===================================================================
diff -u -r73d8423edc56daed591bc0b3f7baee5540aea423 -r01892698468068bb97a80a84c96a6d7c5d6fde9b
--- firmware/App/Services/SystemCommTD.h	(.../SystemCommTD.h)	(revision 73d8423edc56daed591bc0b3f7baee5540aea423)
+++ firmware/App/Services/SystemCommTD.h	(.../SystemCommTD.h)	(revision 01892698468068bb97a80a84c96a6d7c5d6fde9b)
@@ -33,14 +33,8 @@
 
 // ********** public definitions **********
 
-#define MESSAGE_SYNC_BYTE           0xA5                                                            ///< Denali message syncronization byte.
-
-#define CAN_MESSAGE_PAYLOAD_SIZE    8                                                               ///< CAN frame payload size (in bytes).
-
-#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 NUM_OF_CAN_OUT_BUFFERS      5                                                               ///< Number of CAN buffers for transmit
 #define NUM_OF_CAN_IN_BUFFERS       9                                                               ///< Number of CAN buffers for receiving