Operation
Networking
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide
43
The default value for the
MM
configuration parameter is 0 which enables both the Digi header and the
MAC acknowledgment.
XBee retries configuration
Configures the maximum number of retries the device executes in addition to the three retries
provided by the 802.15.4 MAC.
controls XBee retries configuration. It is also known
as Application Retries.
For each XBee retry, the 802.15.4 MAC can execute up to three retries.
This only applies if MAC Mode configuration has Digi Header enabled.
Transmit status based on MAC mode and XBee retries configurations
When working in API mode, a transmit request frame sent by the user is always answered with a
transmit status frame sent by the device, if the frame ID is non-zero.
The following tables report the expected transmit status for unicast transmissions and the maximum
number of MAC and application retries the device attempts.
The tables also report the transmit status reported when the device detects energy above the CCA
threshold (when a CCA failure happens).
The following table applies in either of these cases:
l
Digi Header is disabled.
l
Digi Header is enabled and XBee Retries (
RR
parameter) is equal to 0 (default configuration).
Mac ACK
Config
Destination reachable
Destination unreachable
CCA failure
happened
TX status
Retries
TX status
Retries
TX
status
Retries
MAC
App
MAC
App
MAC
App
Enabled
00
(Success)
up to
3
0
01 (No
acknowledgment
received)
3
0
02 (CCA
failure)
3
0
Disabled
00
(Success)
0
0
00 (Success)
0
0
02 (CCA
failure)
3
0
The following table applies when:
l
Digi Header is enabled and XBee Retries (
RR
parameter) is bigger than 0.