Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -r46b163d19c65e8c21db7b0247bbb1af0dba1ece5 -ra16225ab0fc1c575ad857ccf1dcccdb7a3aa8eef
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 46b163d19c65e8c21db7b0247bbb1af0dba1ece5)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision a16225ab0fc1c575ad857ccf1dcccdb7a3aa8eef)
@@ -36,6 +36,7 @@
 #include "SystemComm.h"
 #include "SystemCommMessages.h"
 #include "Temperatures.h"
+#include "Timers.h"
 #include "TreatmentEnd.h"
 #include "TreatmentRecirc.h"
 #include "TreatmentStop.h"
@@ -52,6 +53,7 @@
 // ********** private definitions **********
 
 #define MAX_MSGS_BLOCKED_FOR_XMIT       8                   ///< Maximum number of messages to block transmission for.
+#define NUM_CONFIRM_REQUESTS            4                   ///< Number of available confirmation requests.
 
 #pragma pack(push,1)
 /// Payload record structure for block message transmission request.
@@ -67,6 +69,11 @@
 static volatile U16 nextSeqNo = 1;                          ///< Value of sequence number to use for next transmitted message.
 /// List of message IDs that are requested not to be transmitted.
 static BLOCKED_MSGS_DATA_T blockedMessagesForXmit = { 0, 0, 0, 0, 0, 0, 0, 0 };
+static CONFIRMATION_REQUEST_T confirmRequests[NUM_CONFIRM_REQUESTS] =
+                                                   { 0, 0, CONFIRMATION_REQUEST_STATUS_UNUSED,
+                                                     0, 0, CONFIRMATION_REQUEST_STATUS_UNUSED,
+                                                     0, 0, CONFIRMATION_REQUEST_STATUS_UNUSED,
+                                                     0, 0, CONFIRMATION_REQUEST_STATUS_UNUSED, };
 
 // ********** private function prototypes **********
 
@@ -76,6 +83,93 @@
 
 /*********************************************************************//**
  * @brief
+ * The checkConfrimRequestStatus function checks the status of a confirmation request
+ * @details Inputs: confirmRequests[]
+ * @details Outputs: confirmRequests[] cleared if read.
+ * @param request ID
+ * @return CONFIRMATION_REQUEST_STATUS_T
+ *************************************************************************/
+CONFIRMATION_REQUEST_STATUS_T checkConfirmationRequestStatus( U32 request_id )
+{
+    U08 i;
+    CONFIRMATION_REQUEST_STATUS_T status = CONFIRMATION_REQUEST_STATUS_PENDING;
+
+    for ( i=0; i<NUM_CONFIRM_REQUESTS; i++ )
+    {
+        if ( confirmRequests[ i ].requestID == request_id )
+        {
+            if ( TRUE == didTimeout( confirmRequests[ i ].timeStamp, CONFIRMATION_REQUEST_TIMEOUT_MS ) )
+            {
+                status = CONFIRMATION_REQUEST_STATUS_TIMEOUT;
+            }
+            else
+            {
+                status = confirmRequests[ i ].status;
+            }
+            if ( CONFIRMATION_REQUEST_STATUS_PENDING != status)
+            {
+                // Clear the confirmation request
+                confirmRequests[ i ].requestID = 0;
+                confirmRequests[ i ].timeStamp = 0;
+                confirmRequests[ i ].status = CONFIRMATION_REQUEST_STATUS_UNUSED;
+            }
+        }
+    }
+
+    return status;
+}
+
+/*********************************************************************//**
+ * @brief
+ * The sendConfirmationRequest function sends a confirmation request to UI
+ * @details Inputs:
+ * @details Outputs: confirmRequests[].
+ * @param
+ * @return request ID - will be non-zero if sent
+ *************************************************************************/
+U32 sendConfirmationRequest( CONFIRMATION_REQUEST_TYPE_T request_type, U32 reject_reason )
+{
+    MESSAGE_T msg;
+    U08 *payloadPtr = msg.payload;
+    U08 i;
+    static U32 request_id = 0;
+    U32 new_id = 0;
+
+    for ( i=0; i<NUM_CONFIRM_REQUESTS; i++ )
+    {
+        if ( confirmRequests[ i ].status == CONFIRMATION_REQUEST_STATUS_UNUSED )
+        {
+            request_id++;
+            // Save the confirmation request info
+            confirmRequests[ i ].requestID = request_id;
+            confirmRequests[ i ].timeStamp = getMSTimerCount();
+            confirmRequests[ i ].status = CONFIRMATION_REQUEST_STATUS_PENDING;
+            new_id = request_id;
+
+            // Create a message record
+            blankMessage( &msg );
+            msg.hdr.msgID = MSG_ID_HD_REQUEST_UI_CONFIRMATION;
+            // The payload length is U32 Request ID, U32 Type, U32 Reject Reason
+            msg.hdr.payloadLen = 3 * sizeof( U32 );
+
+            memcpy( payloadPtr, &request_id, sizeof( U32 ) );
+            payloadPtr += sizeof( U32 );
+            memcpy( payloadPtr, &request_type, sizeof( U32 ) );
+            payloadPtr += sizeof( U32 );
+            memcpy( payloadPtr, &reject_reason, sizeof( U32 ) );
+
+            // Serialize the message (w/ sync, CRC, and appropriate CAN padding) and add serialized message data to appropriate comm buffer
+            serializeMessage( msg, COMM_BUFFER_OUT_CAN_HD_2_UI, ACK_NOT_REQUIRED );
+
+            break;
+        }
+    }
+
+    return new_id;
+}
+
+/*********************************************************************//**
+ * @brief
  * The serializeMessage function serializes a given message into a given
  * array of bytes.  A sequence # is added to the message here and the ACK
  * bit of the sequence # is set if ACK is required per parameter.  A sync byte
@@ -7324,4 +7418,48 @@
     return result;
 }
 
+/*********************************************************************//**
+ * @brief
+ * The handleUIConfirmationResponse function handles a UI response for
+ * confirmation request.
+ * @details Inputs: none
+ * @details Outputs: message handled
+ * @param message a pointer to the message to handle
+ * @return none
+ *************************************************************************/
+void handleUIConfirmationResponse( MESSAGE_T *message )
+{
+    BOOL result = FALSE;
+
+    if ( message->hdr.payloadLen == 2 * sizeof(U32) )
+    {
+        U32 request_id;
+        CONFIRMATION_REQUEST_STATUS_T status;
+        U08 i;
+
+        memcpy( &request_id, message->payload, sizeof(U32) );
+        memcpy( &status, ( message->payload + sizeof(U32) ), sizeof(U32) );
+
+        for ( i=0; i<NUM_CONFIRM_REQUESTS; i++ )
+        {
+            if ( confirmRequests[ i ].requestID == request_id )
+            {
+                if ( ( CONFIRMATION_REQUEST_STATUS_REJECTED == status ) ||
+                     ( CONFIRMATION_REQUEST_STATUS_ACCEPTED == status ) )
+                {
+                    confirmRequests[ i ].status = status;
+                }
+                else
+                {
+                    // illegal response
+                    // TODO set alarm?
+                }
+            }
+        }
+    }
+
+    // TODO is ACK needed?
+    sendAckResponseMsg( (MSG_ID_T)message->hdr.msgID, COMM_BUFFER_OUT_CAN_HD_2_UI, result );
+}
+
 /**@}*/