/// <summary>
        /// Update OBIS code.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void ObjectTypeCb_SelectedIndexChanged(object sender, EventArgs e)
        {
            LogicalNameTb.Items.Clear();
            bool first = true;

            foreach (KeyValuePair <string, string> it in converter.GetObisCodesByType((ObjectType)ObjectTypeCb.SelectedItem))
            {
                LogicalNameTb.Items.Add(it.Key);
                if (first)
                {
                    LogicalNameTb.Text = it.Key;
                    DescriptionTb.Text = it.Value;
                    first = false;
                }
            }
        }
        /// <summary>
        /// Object type has changed.
        /// </summary>
        private void ObjectTypeCb_SelectedIndexChanged(object sender, EventArgs e)
        {
            LogicalNameTb.Items.Clear();
            bool first = true;

            foreach (KeyValuePair <string, string> it in converter.GetObisCodesByType((ObjectType)ObjectTypeCb.SelectedItem))
            {
                LogicalNameTb.Items.Add(it.Key);
                if (first)
                {
                    LogicalNameTb.Text = it.Key;
                    DescriptionTb.Text = it.Value;
                    first = false;
                }
            }
            //Restore default columns if old target is association LN.
            if (Target is GXDLMSAssociationLogicalName)
            {
                VersionCb.Enabled = true;
                CreateAccessrightsColumns(version);
            }
            if (Target == null || Target.ObjectType != (ObjectType)ObjectTypeCb.SelectedItem)
            {
                Target = GXDLMSClient.CreateObject((ObjectType)ObjectTypeCb.SelectedItem);
            }
            UpdateAttributes();
            //Update max version number.
            VersionCb.Items.Clear();
            for (int pos = 0; pos != 1 + (Target as IGXDLMSBase).GetMaxSupportedVersion(); ++pos)
            {
                VersionCb.Items.Insert(0, pos);
            }
            if (Target is GXDLMSAssociationLogicalName)
            {
                VersionCb.SelectedItem = version;
                VersionCb.Enabled      = false;
            }
            else
            {
                VersionCb.SelectedIndex = 0;
            }
        }