Eccel Technology Ltd BIORADRDR0200 Manuel D’Utilisation

4.2.16 Recover Value (0x10)

Table 4.16

The Recover Value command takes as arguments the address of the block where the value is stored (Block Address),
the offset of the data buffer where the value and read address will be stored (Data Buffer Offset), the Authentication
Key Number and (optionally) the Authentication Key. This command has the same functionality as the Read Value
command, except that it can be used on a block which is corrupted – it tries to recover data from a corrupted block.
The format of a value-type block allows for some bits to be corrupted and it still be possible to read and recover the
proper value. The 4-byte signed value followed by 1-byte address value is stored in the Data Buffer under the Data
Buffer Offset index.

Command Number

Command Name

Valid Tag Types

Argument Offset [bytes]

0x00

0x01

0x02

0x03

Argument Name

Block Address

Data Buffer Offset

Authentication Key

Number

Authentication Key

Argument Size [bytes]

0x01

0x06

Argument Description

Address of the block in

the memory from

which the value is to be

read. The block must

be formatted as a value

type block before

reading.

Buffer offset in bytes

from where the data

from the tag is to be

stored. Total read size

and the offset cannot

exceed the data buffer

length.

The 6 least significant

bits define the

Authentication Key

Number from 0 to 39

that is to be used to

read the data. If the

most significant bit (bit

7) is set, then the key

will be used as Key B. If

it is zero it will be used

as Key A. If bit 6 is set,

then the key will be

taken from the

argument list (next 6

bytes).

Optional parameter

used when bit 6 in the

preceding

Authentication Key

Number argument is

set. This key will be

used as Key B if bit 7 of

the Authentication Key

Number is set, or as

Key A if it is zero. The

byte order is the least

significant byte first.

0x10

Recover Value

Mifare Classic