Index: sources/update/MsgLink.h
===================================================================
diff -u -r20b370a54d2737831b307a0de82aec9e06e2b772 -r110fa8df5fc77830fa05d04af55b349dd8f9c6d9
--- sources/update/MsgLink.h	(.../MsgLink.h)	(revision 20b370a54d2737831b307a0de82aec9e06e2b772)
+++ sources/update/MsgLink.h	(.../MsgLink.h)	(revision 110fa8df5fc77830fa05d04af55b349dd8f9c6d9)
@@ -149,9 +149,11 @@
         // We are expecting data.
         _expecting = true;
 
-        _wasData = 
-            (msgId == SwUpdateCanMsgIds::DataBufferId_FW) ||
-            (msgId == SwUpdateCanMsgIds::DataBufferId_FPGA);
+        _wasData =
+            (msgId == SwUpdateCanMsgIds::DataBufferId_HD_FW)   ||
+            (msgId == SwUpdateCanMsgIds::DataBufferId_HD_FPGA) ||
+            (msgId == SwUpdateCanMsgIds::DataBufferId_DG_FW)   ||
+            (msgId == SwUpdateCanMsgIds::DataBufferId_DG_FPGA);
 
         // Either command or data. if data use ResponseId, 
         // if a command and verify or version use VerifyId else ResponseId.
Index: sources/update/UiProtocol.cpp
===================================================================
diff -u -r61c46e9379ca82d826fbe7fae018b8362a107d9d -r110fa8df5fc77830fa05d04af55b349dd8f9c6d9
--- sources/update/UiProtocol.cpp	(.../UiProtocol.cpp)	(revision 61c46e9379ca82d826fbe7fae018b8362a107d9d)
+++ sources/update/UiProtocol.cpp	(.../UiProtocol.cpp)	(revision 110fa8df5fc77830fa05d04af55b349dd8f9c6d9)
@@ -374,8 +374,10 @@
         // Create the security token and send it.
         SwUpdate_createSecurity((uint8 *) &msg, sizeof(SwUpdateDataBuffer));
         ok = _link.sendOk(
-            (_target == HD) || (_target == DG) ? 
-                SwUpdateCanMsgIds::DataBufferId_FW : SwUpdateCanMsgIds::DataBufferId_FPGA, 
+            (_target == HD) ? SwUpdateCanMsgIds::DataBufferId_HD_FW :
+            (_target == DG) ? SwUpdateCanMsgIds::DataBufferId_DG_FW :
+            (_target == HDFPGA) ? SwUpdateCanMsgIds::DataBufferId_HD_FPGA :
+                SwUpdateCanMsgIds::DataBufferId_DG_FPGA,
             (uint8*)&msg, _retryEffort);
         if ((_desired != Complete) || (!ok)) {
             return false;
@@ -414,8 +416,10 @@
     // Create the security token and send it.
     SwUpdate_createSecurity((uint8 *) &msg, sizeof(SwUpdateDataBuffer));
     bool ok = _link.sendOk(
-        (_target == HD) || (_target == DG) ? 
-            SwUpdateCanMsgIds::DataBufferId_FW : SwUpdateCanMsgIds::DataBufferId_FPGA, 
+        (_target == HD) ? SwUpdateCanMsgIds::DataBufferId_HD_FW :
+        (_target == DG) ? SwUpdateCanMsgIds::DataBufferId_DG_FW :
+        (_target == HDFPGA) ? SwUpdateCanMsgIds::DataBufferId_HD_FPGA :
+        SwUpdateCanMsgIds::DataBufferId_DG_FPGA,
         (uint8*)&msg, _retryEffort);
 
     return (ok && (_link.numberRetries() <= _maxCyberRetries));
Index: sources/update/UpdateProtocol.h
===================================================================
diff -u -r20b370a54d2737831b307a0de82aec9e06e2b772 -r110fa8df5fc77830fa05d04af55b349dd8f9c6d9
--- sources/update/UpdateProtocol.h	(.../UpdateProtocol.h)	(revision 20b370a54d2737831b307a0de82aec9e06e2b772)
+++ sources/update/UpdateProtocol.h	(.../UpdateProtocol.h)	(revision 110fa8df5fc77830fa05d04af55b349dd8f9c6d9)
@@ -55,13 +55,17 @@
  * on each 8 byte transfer... The only way to 100% be sure the
  * streams don't get confused by the "mailbox" system used by
  * TI style CAN bus HW is to make them distinct command IDs.
+ *
+ * The app msgs are < 0x8000. We start there.
  */
 typedef enum SwUpdateCanMsgIds {
-    CommandId = 1,          ///< SwUpdateCommand ID.
-    DataBufferId_FW = 2,    ///< SwUpdateDataBuffer ID for FW.
-    DataBufferId_FPGA = 3,  ///< SwUpdateDataBuffer ID for FPGA.
-    ResponseId = 4,         ///< SwUpdateResponse ID.
-    VerifyId = 5,           ///< SwUpdateResponse ID.
+    CommandId = 0x8001,          ///< SwUpdateCommand ID.
+    DataBufferId_HD_FW = 0x8002,    ///< SwUpdateDataBuffer ID for FW.
+    DataBufferId_HD_FPGA = 0x8003,  ///< SwUpdateDataBuffer ID for FPGA.
+    DataBufferId_DG_FW = 0x8004,    ///< SwUpdateDataBuffer ID for FW.
+    DataBufferId_DG_FPGA = 0x8005,  ///< SwUpdateDataBuffer ID for FPGA.
+    ResponseId = 0x8006,         ///< SwUpdateResponse ID.
+    VerifyId = 0x8007,           ///< SwUpdateResponse ID.
     NumMsgIds               ///< Always last.    
 } SwUpdateCanMsgIds;