Campbell RF401, Инструкция по эксплуатации, Страница: 127 / 130

Appendix M. PakBus Networking Details
M-3
M.6.1 Hop Metric Code
The HopMetric code corresponds to the following times that are seen in
PakBus Graph:
HopMetric Code Time
0 200 msec or less
1 1000 msec
2 5000 msec
3 10000 msec
4 20000 msec
The duty cycle portion of the hop metric is:
Standby Mode Hop Metric
<24 mA Always On 0
< 4 mA 1/2 sec Cycle 1
< 2 mA 1 sec Cycle 1
<.4 mA 8 sec Cycle 2
M.7 RF Router
The signal strength portion of the hop metric is determined by:
Signal level for upper threshold of hop metric going from
2 -> 1 => 60 (-80 dBm)
Signal level for lower threshold of hop metric going from
1 -> 2 => 49 (-94 dBm)
These two hop metrics are added together to give the composite hop metric.
For example, if the radio was always ON, and signal level >60, the composite
hop metric would be 1 (1000 msec). If the radio was doing the ½ sec Cycle,
and signal level was <49, the composite hop metric would be 3 (5000 msec).
The signal strength that is used for the hop metric is averaged, and incorporates
hysterisis so that it neither changes quickly nor sporadically. The radio keeps
track of the averaged signal strength for 10 individual neighbo
u
ring nodes (30
for the RF Router mode).
RF401 or RF430 radios using PakBus Node protocol can be set as a PakBus
RF router. In this mode, the radio is not attached to any datalogger or PC; it is
ONLY
a RF router. The radio will maintain a routing table, discover additional
nodes, and route PakBus packets based on its routing table. The radio will also
have a Beacon Interval, Hello List, Verify Interval, and Central Router setting.
These settings function as they do in the CR1000. The default settings are:
Beacon Interval: 60 seconds
Verify Interval: 150 seconds
Hello List: None
Central Router: None