User's Manual

COBALT UHF-SERIES CHAPTER 5: COMMAND PROTOCOLS
PAGE 49 OF 140
5.3 ABX COMMAND PROTOCOL OVERVIEW
There are two versions of the ABx Command Protocol that are supported by the
Cobalt UHF Serial Controller, they are:
 ABx Fast (default)
 ABx Standard
The ABx Fast Command Protocol has a single-byte based packet structure that
permits the execution of RFID commands while requiring the transfer of fewer total
bytes than ABx Standard. ABx Fast is the default command protocol used by Cobalt
UHF Serial RFID Controller. It can be used with or without a checksum byte.
The ABx Standard Command Protocol
uses a double-byte, word based format that
shares a common syntax with most existing RFID systems produced by Escort
Memory Systems. This protocol offers legacy support, which may be required by
existing PLC applications that only support a 2-byte word packet format. If your
application requires compatibility with existing or legacy RFID devices from
Datalogic’s EMS product line, use ABx Standard. ABx Standard does not support the
use of a checksum byte.
NOTE:
By default, the UHF-CNTL-232-02 is configured to use the ABx Fast Command
Protocol. ABx Fast (as the name suggests) is the faster and more efficient of the two
ABx protocols, offering increased communication speed and error immunity.
5.3.1 ABx Command Packet Structure
All ABx-based RFID commands contain certain fundamental packet elements,
including a
Command Header, a Command ID, one or more Command
Parameters (when applicable) and a Command Terminator.
Command Packet Structure = [Command Header + Command ID + Command
Parameters + Command Terminator]
5.3.2 ABx Protocols - Headers and Terminators
In ABx Standard, commands begin with the one-byte command header "0xAA," and
end with the two-byte command terminator "0xFF, 0xFF".
In ABx Fast, commands begin with the two-byte command header “0x02, 0x02” and
end with the one-byte command terminator “0x03.”
See the table below for further clarification.
ABx Protocols - Headers and Terminators
ABX PROTOCOL HEADER TERMINATOR
ABx Fast
0x02, 0x02 0x03
ABx Standard
0xAA 0xFF, 0xFF
Table 5-4: ABx Protocols - Headers and Terminators