Campbell Scientific RF401-series and RF430-series Spread Spectrum Data Radios/Modems User Manual
Page 113
Appendix L. RF401/RF411 Average Current Drain Calculations
EXAMPLE #1 (Remote RF401/RF411 in default standby mode)
There is a Point-to-Point system with base RF401/RF411 and remote
RF401/RF411. The remote station senses weather conditions and sends low-
resolution data to final storage. The base station collects 10 data points from
the remote station once per minute. Both stations are configured for “<4 mA,
½ sec Cycle” (the default standby mode). The remote station operates on solar
power and we are interested in knowing the average current drain contribution
of the RF401/RF411. From the above section:
It = Is + Id + Ir + Ii
Calculating each term:
Is = table mA value = 4 mA
It ≈ 6.1 mA
The dominant average current drain contributors are the standby mode current
and the “time of inactivity to sleep” currents. If large quantities of data per
minute were being generated/collected, then Id would become a significant
contributor. In this example the “time of inactivity to sleep” could be reduced
because only 10 data points are sent per collection. Try a value of 10 instead
of 50 reducing the Ii contribution from 2 mA to 0.4 mA.
mA
0.08
mA
73
ms
60,000
ms
65
mA
73
(ms)
T
(ms)]
N
2
(ms)
45
[
Id
=
Ч
=
Ч
+
=
mA
0.008
mA
24
(ms)
60,000
(ms)
20
Ir
=
×
=
mA
2
mA
24
(ms)
60,000
ms
5000
Ii
=
×
=
L-3