User's Manual

COBALT UHF-SERIES CHAPTER 8: STANDARD TCP/IP INTERFACE
PAGE 124 OF 140
8.3 STANDARD TCP/IP - COMMAND & RESPONSE
EXAMPLES
In standard TCP/IP, RFID commands issued by the host resemble Modbus TCP
commands. The Cobalt handles all handshaking tasks.
Moreover, the command & response packets need an additional word at the
beginning of the string:
Protocol Header 0xFF in MSB, <Node ID> in LSB.
Please notice that these two bytes are not considered part of the CBx command
packet and should not be counted in the Overall Length.
Below is the structure of the additional word required, named as Word # 00:
WORD # COMMAND PACKET ELEMENT MSB LSB
00
Protocol Header in MSB: 0xFF
Node ID in LSB
0xFF <Node ID>
And similarly for the response:
WORD # RESPONSE PACKET ELEMENT MSB LSB
00 Protocol Header
in MSB: 0xFF
Node ID Echo
in LSB
0xFF <Node ID
Echo>
NOTE: These first two bytes will not be returned in the response packet for commands
executed by Node 01.
Therefore, the command packet structure for standard TCP/IP applications is:
Figure 8-3: Standard TCP/IP Protocol Command Packet Structure