User's Manual

COBALT UHF-SERIES CHAPTER 5: COMMAND PROTOCOLS
PAGE 69 OF 140
04
Timeout Value:
2-byte integer
representing the length of time allowed for
the completion of the command (when
applicable). Measured in one-millisecond
increments, the Timeout Value can have a
value of 0x0001 to 0xFFFE (1 - 65,534
milliseconds).
<Timeout
MSB>
<Timeout
LSB>
05
Start Address:
2-byte integer indicating
the location of tag memory where a read or
write operation will begin (when applicable)
<Start MSB> <Start LSB>
06
Block Size:
2-byte integer indicating the
number of bytes that are to be read from or
written to a tag during the operation (when
applicable)
<Size MSB> <Size LSB>
07
Additional Data:
(bytes 1 & 2) used to
hold 2-bytes of data used for writes and
fills (when applicable)
<D1> <D2>
08
Additional Data:
(bytes 3 & 4) used to
hold an additional 2-bytes of data for writes
(when applicable)
<D3> <D4>
Table 5-13: CBx Command Packet Structure
5.5.3 CBx Response Packet Structure
After executing a command, the controller will generate a host-bound response
message. The response message will contain EITHER the results of the attempted
command or an error code indicating the reason the operation could not be
completed successfully. Below is the structure of a standard CBx response packet.
CBx Response Packet Structure
WORD # RESPONSE PACKET ELEMENT MSB LSB
01
Overall Length:
2-byte integer indicating
the number of “
words
” in the response
packet. This value will always be at least
6 words
.
0x00 0x06 +
(number of
additional data
words
retrieved, if
any)
02
0xAA
in MSB
Command Echo:
single-byte LSB value
identifies the command that was
performed.
0xAA <Command
Echo>