User Manual

CHAPTER 6: COMMAND PROTOCOLS
COBALT HF RFID CONTROLLERS OPERATOR’S MANUAL
P/N: 17-1320 REV 01 (03-06) PAGE 61 OF 116
6.2.2 ABx Fast - Command Packet Structure
The packet structure of every ABx Fast command contains certain basic elements,
including a Command Header, a number of command parameters and a Terminator.
COMMAND PACKET PARAMETER CONTENT SIZE
COMMAND HEADER:
The first two bytes of an ABx Fast Command Packet:
0x02, 0x02 2 bytes
COMMAND SIZE:
This 2-byte value defines the number of bytes in the packet
(excluding Header, Command Size, Checksum and
Terminator).
0x0008
2-byte
integer
COMMAND ID:
This single-byte value indicates the RFID command to execute.
0x06
(Write Data)
1 byte
START ADDRESS:
The 2-byte Start Address parameter indicates the location of
tag memory where a read or write operation shall begin.
0x0000
2-byte
integer
READ/WRITE LENGTH:
The 2-byte Read/Write Length parameter represents the
number of bytes that are to be retrieved from or written to the
RFID tag.
0x0001
2-byte
integer
TIMEOUT VALUE:
This 2-byte integer indicates the maximum length of time for
which the controller will attempt to complete the command.
Measured in milliseconds, this value can have a range of
0x0001 to 0xFFFE or between 1 and 65,534 msecs (0x07D0 =
2000 x .001 = 2 seconds).
0x07D0
2-byte
integer
ADDITIONAL DATA:
This parameter uses one byte to hold a single character for fill
operations and supports the use of multiple bytes when several
characters are needed for write commands (when applicable).
0x00
One or
more bytes
(when
applicable)
CHECKSUM:
This optional parameter holds a single-byte checksum (only
applicable when using ABx Fast with Checksum).
optional
1 byte
(when
applicable)
TERMINATOR:
Single-byte command packet terminator:
0x03 1 byte
Table 6-1: ABx Fast - Command Packet Structure