.. /*
    * This file is part of the SavaPage project <https://www.savapage.org>.
    * Copyright (c) 2026 Datraverse B.V.
    * Author: Rijk Ravestein.
    *
    * SPDX-FileCopyrightText: (c) 2020 Datraverse B.V. <info@datraverse.com>
    * SPDX-License-Identifier: CC-BY-SA-4.0
    *
    * For more information, please contact Datraverse B.V. at this
    * address: info@datraverse.com
    */

.. _app-nfc-reader-local:

Local Card Reader
-----------------

A *Local Card Reader* is an NFC Reader that functions as USB Keyboard
Emulator. At each card swipe the reader must react by “typing” the
card's UID (Card Number) appended by a Carriage Return (CR).
SavaPage makes use of this function by capturing [2]_ the
keystrokes at Login time in the Web App.

.. note::

   The way a reader formats the UID can deviate from the |PRODUCT_NAME|
   HEX/LSB standard. Therefore you need to specify the format at the
   interfaces where the reader's UID is used. Most keyboard emulating
   readers can be configured to a specific output format and byte order.

.. tip::

   At the time of this writing
   `StrongLink <http://www.stronglink-rfid.com>`__ sells a reliable Plug
   and Play USB Keyboard Emulating Card Reader (SL040A) for a
   competitive price. The reader supports UID reads for Mifare Mini,
   Mifare 1k, Mifare 4k, Mifare Plus, Ultralight, DesFire and
   Mifare_ProX cards.


.. [2]
   SavaPage uses a short time limit to capture the keystrokes from a
   Local Card Reader. The time limit (milliseconds) is contained in the
   configuration key ``webapp.card-local.keystrokes-max-msecs``. Do not
   change this value, except when requested by the SavaPage support
   desk.