User's Manual

COBALT UHF-SERIES CHAPTER 5: COMMAND PROTOCOLS
PAGE 68 OF 140
5.5.2 CBx - Command Packet Structure
As noted, CBx commands contain a minimum of six words. Below is the structure of
a standard CBx command packet.
Table 5-12: CBx Command Packet Structure
CBx Command Packet Structure
(MSB = Most Significant Byte, LSB = Least Significant Byte)
WORD # COMMAND PACKET ELEMENT MSB LSB
01
Overall Length:
2-byte integer indicating
the number of 16-bit “
words
” in the
command packet.
Note: this value will always be at least
6
,
as each command has a minimum of 12-
bytes (or 6 words). Overall Length will
increase when additional data words are
used in the command (for fills, writes, etc.).
0x00 0x06 +
(number of
additional data
words, if any)
02
0xAA
in MSB
Command ID
: single-byte value in LSB
indicates command to perform
0xAA <Command
ID>
03
0x00
in MSB
Node ID:
LSB value indicates the Node ID
number of the device to which the
command is intended.
Note: this value must be 0x20 (Node ID
32) when the command is directed to a
Gateway or Hub, and must be 0x01 (Node
ID 01) when the command is directed to a
Cobalt IND controller.
0x00 <Node ID>