Campbell Scientific RF401A-Series Spread Spectrum Radios - Manual (Page 31)

RF401A-Series Spread Spectrum Radio
Always
on, 8 Sec
Header
< 15 mA The radio receiver is always on. A wakeup header
of 8.2 seconds is transmitted at the beginning of
the first transmission occurring after a period of RF
inactivity to ensure that other radios in the network
set to an 8 second mode are awake and ready to
communicate. Using this setting is uncommon,
generally only used in a base radio that
communicates with a CR200-series datalogger
configured with a power mode of “8 second” (no
header).
0.5
Second
< 2 mA The radio receiver is turned on every 0.5 seconds
for 100 milliseconds to look for RF activity. The
radio transmits a 700 millisecond wakeup header
with the first transmission occurring after a period
of RF inactivity. This is the most common setting
in networks that do not contain CR200(X)-series
dataloggers.
1 Second < 1 mA The radio receiver is turned on every 1 second for
100 milliseconds to look for RF activity. The radio
transmits a 1.2 second wakeup header with the first
transmission occurring after a period of RF
inactivity. This is the most common setting in
networks that contain CR200(X)-series
dataloggers.
8 Second < 0.3 mA The radio receiver is turned on every 8 seconds for
100 milliseconds to look for RF activity. The radio
transmits an 8.2 second wakeup header with the
first transmission occurring after a period of RF
inactivity. Only use this setting in networks where
time between communications is long (hours) and
saving an average an additional 1 to 1.5 mA is
essential.
11.1.9 Retry Level
An advantage of using one of the PakBus® protocol modes is that the radios
will retry packet delivery at the RF level. This setting specifies the level to
which the radio should retry to deliver an unacknowledged RF packet
transmission. When an RF packet fails to be acknowledged by the destination,
the radio will delay a random amount of time before resending the packet
again. A receiving radio responds to the sending radio with an ACK packet for
every radio packet it receives addressed to it with a valid CRC.
Retry Level Retry Count Random Delay Slots Transmit Timer
None
0 0 65535
Low 3 1 400
Medium 5 2 400
High 7 3 400
21