User's Manual

COBALT UHF-SERIES CHAPTER 5: COMMAND PROTOCOLS
PAGE 73 OF 140
5.5.6 CBx Multi-Tag Response Packet Structures
When executing multi-tag commands designed to retrieve information from several
tags at once (for example CBx Command 0x92: Multi-Tag Read ID and Data All), the
RFID controller will generate separate host-bound response packets for each tag that
has been read. Below is the structure of a basic CBx multi-tag response packet
generated by the controller at Node 01.
CBx Multi-tag Response Packet Structure (One Packet for Each Tag Read)
WORD # RESPONSE PACKET ELEMENT MSB LSB
01
Overall Length
: 2-byte integer indicates the
number of “
words
” in the response packet.
0x00 0x06 +
(number of
additional
words
retrieved)
02
0xAA
in MSB
Command Echo
: single-byte value identifies
the command that was performed in LSB
0xAA <Command
Echo>
03 Instance Counter: 1-byte MSB value indicates
number of responses generated by the Node ID
identified in the LSB.
Node ID Echo: 1-byte value indicates the Node
ID of the RFID controller that performed the
command.
<IC> 0x01
04
Month and Day Timestamp
<Month> <Day>
05
Hour and Minute Timestamp
<Hour> <Minute>
06
Second Timestamp
in MSB
Additional Data Length
: single-byte LSB
value indicates the number of additional bytes
retrieved, includes both Tag ID and Read Data
bytes (when applicable)
<Second> <N-bytes>
07
Tag ID bytes 1 and 2
: holds the first two bytes
of the Tag ID number
<ID byte 1> <ID byte 2>
08
Tag ID bytes 3 and 4
<ID byte 3> <ID byte 4>
09
Tag ID bytes 5 and 6
<ID byte 5> <ID byte 6>
10
Tag ID bytes 7 and 8
<ID byte 7> <ID byte 8>
11
Read Data bytes 1 and 2
: holds 2 bytes of
retrieved data from tag read operations
<D01> <D02>
…
…
… …
18
Read Data bytes 15 and 16
<D15> <D16>
Table 5-16: CBx Multi-Tag Response Packet Structure