Index: firmware/App/Services/SystemComm.c
===================================================================
diff -u -r46b163d19c65e8c21db7b0247bbb1af0dba1ece5 -r72ab02a2c5612b5ee178d682671b5e34d16ca3c3
--- firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 46b163d19c65e8c21db7b0247bbb1af0dba1ece5)
+++ firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 72ab02a2c5612b5ee178d682671b5e34d16ca3c3)
@@ -55,7 +55,10 @@
 
 #define MSG_NOT_ACKED_MAX_RETRIES       20      ///< Maximum number of times a message that requires ACK that was not ACK'd can be re-sent before alarm
 #define PENDING_ACK_LIST_SIZE           25      ///< Maximum number of Denali messages that can be pending ACK at any given time
-
+
+#define MAX_FPGA_CLOCK_SPEED_ERRORS     3       ///< maximum number of FPGA clock speed errors within window period before alarm
+#define MAX_FPGA_CLOCK_SPEED_ERROR_WINDOW_MS    (10 * SEC_PER_MIN * MS_PER_SECOND)    ///< FPGA clock speed error window
+
 #pragma pack(push, 1)
 
 /// Record for transmitted message that is pending acknowledgment from receiver.
@@ -142,6 +145,9 @@
 
     // Initialize bad message CRC time windowed count
     initTimeWindowedCount( TIME_WINDOWED_COUNT_BAD_MSG_CRC, MAX_COMM_CRC_FAILURES, MAX_COMM_CRC_FAILURE_WINDOW_MS );
+
+    // Initialize FPGA clock speed error time windowed count
+    initTimeWindowedCount( TIME_WINDOWED_COUNT_FPGA_CLOCK_SPEED_ERROR, MAX_FPGA_CLOCK_SPEED_ERRORS, MAX_FPGA_CLOCK_SPEED_ERROR_WINDOW_MS);
 
     // Initialize pending ACK list
     for ( i = 0; i < PENDING_ACK_LIST_SIZE; i++ )
@@ -256,7 +262,7 @@
  * @return none
  *************************************************************************/
 void execSystemCommRx( void )
-{
+{
     // Parse messages from comm buffers and queue them
     processIncomingData();
 
@@ -698,7 +704,7 @@
 {
     BOOL isThereMsgRcvd = TRUE;  // Assume TRUE at first to get into while loop
     MESSAGE_WRAPPER_T message;
-
+
     while ( TRUE == isThereMsgRcvd )
     {
         // See if any messages received