Extendid; Baudrate Control Register (0Ch); Resetting The Baudrate To Default - Elatec TWN3 Mini Reader Mifare NFC Technical Manual

5.3.5 ExtendID

If set, the unique serial number (UID) of the transponder is extended by a single prefix byte. This bit
has only effect for ISO14443A transponders.
This setting affects the commands continuous reading („c‟), single tag select („s‟) and multi tag select
(„m‟).
Default value: 0
Possible values for the prefix byte are:
Prefix Description
01h Cascade Level 1 transponder, e.g. Mifare® Classic
02h Cascade Level 2 transponder, e.g. Mifare® Ultralight
03h Cascade Level 3 transponder

5.4 Baudrate Control Register (0Ch)

The Baudrate control register defines the start-up baudrate of the reader. For baudrate values, refer to
the tables below:
Baudrate Control Register
Bit 7 Bit 6
RFU RFU
BS2 BS1
0 0
0 0
0 1
0 1
1 0
1 0
1 1
1 1

5.4.1 Resetting the baudrate to default

The reader has a built-in mechanism to reset the baudrate to the default value of 9600 bps. This is
useful, if no communication is possible any more due to an errant setting of the Baudrate control
register. The reset can be done by sending a byte sequence at 9600 bps to the reader. If the
sequence matches, the reader turns its baudrate setting to 9600 bps. This configuration remains valid
until a subsequent reset or power-down event occurs. The user may now write the desired baudrate
setting to the Baudrate Control Register. After that, a reset must be executed, so that the new settings
may take effect.
In order to reset the baudrate, the host has to send the value FFh at 9600 bps three times to the
reader. The bytes must have a temporal distance of at least 100ms. If a valid sequence is recognized,
the reader switches to 9600 bps and sends an acknowledge to the host („B<CR><LF>‟) using the
ASCII protocol.
Elatec GmbH
Bit 5 Bit 4
RFU RFU
BS0 Resulting Baudrate
0 9600 bps (default)
1 19200 bps
0 38400 bps
1 57600 bps
0 115200 bps
1 reserved
0 reserved
1 reserved
Bit 3 Bit 2
RFU BS2
Bit 1 Bit 0
BS1 BS0
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