Campbell Scientific RF401-series and RF430-series Spread Spectrum Data Radios/Modems User Manual
Page 114

Appendix L. RF401/RF411 Average Current Drain Calculations
EXAMPLE #2 (Base RF401/RF411 in default standby mode)
The base RF401/RF411 in the above example does more receiving and less
transmitting than the remote RF401/RF411 so you might expect less average
current drain, however, the amount of data being transmitted per minute is
small, and the long header required is significant. Here are the results:
It = Is + Ih + Iq + Ir + Ii
Calculating each term:
Is = table mA value = 4 mA
It ≈ 6.9 mA
As in Example #1, the standby mode current, long header, and the “time of
inactivity to sleep” currents dominate the average RF401/RF411 current drains,
so the calculated values for remote and base RF401/RF411s are nearly equal.
Larger data collections would make the Ir contribution more significant.
ms)
700
length
header"
long
"
(default
mA
0.875
mA
73
ms
60,000
ms
700
73
(ms)
T
(ms)
L
Ih
=
=
Ч
=
Ч
=
mA
mA
0.025
mA
73
(ms)
60,000
(ms)
20
Iq
=
×
=
mA
0.026
mA
24
(ms)
60,000
ms]
20
(ms)
45
[
Ir
=
×
+
=
50)
sleep"
to
inactivity
of
time
"
default
(using
mA
2
mA
24
(ms)
60,000
ms
5000
Ii
=
=
×
=
L-4