diff -r 5e1d3c9430e0 -r 1d0711235a61 master/datagram_pair.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/master/datagram_pair.h	Thu Jan 12 17:41:05 2012 +0100
@@ -0,0 +1,62 @@
+/******************************************************************************
+ *
+ *  $Id$
+ *
+ *  Copyright (C) 2006-2012  Florian Pose, Ingenieurgemeinschaft IgH
+ *
+ *  This file is part of the IgH EtherCAT Master.
+ *
+ *  The IgH EtherCAT Master is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License version 2, as
+ *  published by the Free Software Foundation.
+ *
+ *  The IgH EtherCAT Master is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+ *  Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with the IgH EtherCAT Master; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ *  ---
+ *
+ *  The license mentioned above concerns the source code only. Using the
+ *  EtherCAT technology and brand is only permitted in compliance with the
+ *  industrial property and similar rights of Beckhoff Automation GmbH.
+ *
+ *****************************************************************************/
+
+/**
+   \file
+   EtherCAT datagram pair structure.
+*/
+
+/*****************************************************************************/
+
+#ifndef __EC_DATAGRAM_PAIR_H__
+#define __EC_DATAGRAM_PAIR_H__
+
+#include <linux/list.h>
+
+#include "globals.h"
+#include "datagram.h"
+
+/*****************************************************************************/
+
+/** Domain datagram pair.
+ */
+typedef struct {
+    struct list_head list; /**< List header. */
+    ec_datagram_t datagrams[EC_NUM_DEVICES]; /**< Main and backup datagram.
+                                               */
+} ec_datagram_pair_t;
+
+/*****************************************************************************/
+
+void ec_datagram_pair_init(ec_datagram_pair_t *);
+void ec_datagram_pair_clear(ec_datagram_pair_t *);
+
+/*****************************************************************************/
+
+#endif