2 - Connection Types
eDynamo| Secure Card Reader Authenticator | Programmer’s Manual (COMMANDS)
Page 27 of 245 (
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Table 2-3 - Card Data Characteristic
Characteristic Name
Card Data
Properties
Read, Notify
Data Size
Variable (512 max)
UUID (LSB Order)
01:02:B6:0C:41:E3:43:F8:8F:89:82:AD:F8:E6:08:05
Description/Usage
Contains the card data.
If the host software configures the
Card Data
characteristic to enable
notifications, the device sends card data to the host in multiple notification
messages when a card is swiped. This is the fastest way for the device to
transmit card data. The first byte of each notification message always
contains the block identifier of the card data, starting with block 0 for the
first message and incrementing in subsequent messages. The host software
can use the block identifier field to detect whether blocks have been lost due
to communication loss or out-of-range problems. The remaining bytes of
each notification message contain card data. After the device has sent all
card data, it sends one more notification message with block identifier 0xFF
to indicate all the card data has been sent. This last notification message also
contains a second byte indicating the total number of blocks of card data it
transmitted.
If the host configures the
Card Data
characteristic to disable notifications
(default configuration), the device does not include block identifier fields in
the blocks; the read simply fails if a communication error occurs. The host
software must read the card data from the
Card Data
characteristic in blocks
using long reads, and must use the
Data Ready
and
Data Read Status
characteristics.
Table 2-4 - Data Ready Characteristic
Characteristic Name
Data Ready
Properties
Notify
Data Size
4
UUID (LSB Order)
02:02:B6:0C:41:E3:43:F8:8F:89:82:AD:F8:E6:08:05
Description/Usage
Contains the characteristic identifier (byte 0), characteristic block identifier
(byte 1), and the block length (byte 2 and 3 LSB first) of the data that is
ready to be read. The characteristic identifiers are defined as 0 = Command
data, 1 = Card or notification data. The first block of card or notification
data is block 0, the second block is block 1, and so on. The host software
knows it has received all available data when the data block is less than 512
bytes long. If the last block of card data happens to be exactly 512 bytes
long, the device sends an additional
Data ready
notification with a block
length of zero.
