Index: firmware/App/Services/SystemComm.h
===================================================================
diff -u -r9864b14f76782f1e68bf266dcd843451748715a0 -r6c60d0d0300828750c76f2e397d4e7ccaa84bbb2
--- firmware/App/Services/SystemComm.h	(.../SystemComm.h)	(revision 9864b14f76782f1e68bf266dcd843451748715a0)
+++ firmware/App/Services/SystemComm.h	(.../SystemComm.h)	(revision 6c60d0d0300828750c76f2e397d4e7ccaa84bbb2)
@@ -49,7 +49,7 @@
 BOOL isDGCommunicating( void );
 BOOL isUICommunicating( void );
 BOOL uiCommunicated( void );
-#ifdef ACK_IMPLEMENTED
+#ifndef ACK_NOT_IMPLEMENTED
 BOOL addMsgToPendingACKList( MESSAGE_T *msg, COMM_BUFFER_T channel, U08 *msgData, U32 len );
 #endif