diff --git a/class/netdiagdevice.class.php b/class/netdiagdevice.class.php
index 3ea9c88..a0b0c73 100644
--- a/class/netdiagdevice.class.php
+++ b/class/netdiagdevice.class.php
@@ -57,7 +57,7 @@ class NetDiagDevice extends CommonObject
 		'devicetype'    => array('type' => 'varchar(64)', 'label' => 'DeviceType', 'enabled' => 1, 'visible' => 1, 'position' => 40),
 		'note'          => array('type' => 'text', 'label' => 'Note', 'enabled' => 1, 'visible' => 3, 'position' => 50),
 		'date_creation' => array('type' => 'datetime', 'label' => 'DateCreation', 'enabled' => 1, 'visible' => 0, 'notnull' => 1, 'position' => 500),
-		'tms'           => array('type' => 'timestamp', 'label' => 'DateModification', 'enabled' => 1, 'visible' => 0, 'notnull' => 1, 'position' => 501),
+		'tms'           => array('type' => 'timestamp', 'label' => 'DateModification', 'enabled' => 1, 'visible' => 0, 'notnull' => 0, 'position' => 501),
 	);
 
 	public $rowid;
diff --git a/class/netdiagmeasurement.class.php b/class/netdiagmeasurement.class.php
index 5b939e1..85d388b 100644
--- a/class/netdiagmeasurement.class.php
+++ b/class/netdiagmeasurement.class.php
@@ -66,7 +66,7 @@ class NetDiagMeasurement extends CommonObject
 		'measure_status' => array('type' => 'smallint', 'label' => 'MeasureStatus', 'enabled' => 1, 'visible' => 1, 'notnull' => 1, 'default' => 0, 'position' => 50),
 		'date_measure'   => array('type' => 'datetime', 'label' => 'DateMeasure', 'enabled' => 1, 'visible' => 1, 'position' => 55),
 		'date_creation'  => array('type' => 'datetime', 'label' => 'DateCreation', 'enabled' => 1, 'visible' => 0, 'notnull' => 1, 'position' => 500),
-		'tms'            => array('type' => 'timestamp', 'label' => 'DateModification', 'enabled' => 1, 'visible' => 0, 'notnull' => 1, 'position' => 501),
+		'tms'            => array('type' => 'timestamp', 'label' => 'DateModification', 'enabled' => 1, 'visible' => 0, 'notnull' => 0, 'position' => 501),
 	);
 
 	public $rowid;
diff --git a/class/netdiagprotocol.class.php b/class/netdiagprotocol.class.php
index 9e4acad..2379802 100644
--- a/class/netdiagprotocol.class.php
+++ b/class/netdiagprotocol.class.php
@@ -68,7 +68,7 @@ class NetDiagProtocol extends CommonObject
 		'status'            => array('type' => 'smallint', 'label' => 'Status', 'enabled' => 1, 'visible' => 1, 'notnull' => 1, 'default' => 0, 'index' => 1, 'position' => 60, 'arrayofkeyval' => array(0 => 'Draft', 1 => 'Done')),
 		'note'              => array('type' => 'text', 'label' => 'Note', 'enabled' => 1, 'visible' => 3, 'position' => 70),
 		'date_creation'     => array('type' => 'datetime', 'label' => 'DateCreation', 'enabled' => 1, 'visible' => 0, 'notnull' => 1, 'position' => 500),
-		'tms'               => array('type' => 'timestamp', 'label' => 'DateModification', 'enabled' => 1, 'visible' => 0, 'notnull' => 1, 'position' => 501),
+		'tms'               => array('type' => 'timestamp', 'label' => 'DateModification', 'enabled' => 1, 'visible' => 0, 'notnull' => 0, 'position' => 501),
 		'fk_user_creat'     => array('type' => 'integer:User:user/class/user.class.php', 'label' => 'UserAuthor', 'enabled' => 1, 'visible' => 0, 'notnull' => 1, 'position' => 510),
 		'fk_user_modif'     => array('type' => 'integer:User:user/class/user.class.php', 'label' => 'UserModif', 'enabled' => 1, 'visible' => 0, 'position' => 511),
 	);