--- a/master/slave_config.h	Mon Apr 19 21:54:54 2010 +0200
+++ b/master/slave_config.h	Mon Apr 19 21:56:16 2010 +0200
@@ -70,7 +70,9 @@
                                                    configurations. */
     ec_fmmu_config_t fmmu_configs[EC_MAX_FMMUS]; /**< FMMU configurations. */
     uint8_t used_fmmus; /**< Number of FMMUs used. */
-    unsigned int used_for_fmmu_datagram[EC_DIR_COUNT];
+    unsigned int used_for_fmmu_datagram[EC_DIR_COUNT]; /**< Number of FMMUs
+                                                         used for process data
+                                                         exchange datagrams. */
     uint16_t dc_assign_activate; /**< Vendor-specific AssignActivate word. */
     ec_sync_signal_t dc_sync[EC_SYNC_SIGNAL_COUNT]; /**< DC sync signals. */