Campbell Scientific RF400/RF410/RF415 Spread Spectrum Radio/Modem User Manual
Page 82
Appendix L. RF400/RF410 Average Current Drain Calculations
L-4
EXAMPLE #2 (Base RF400/RF410 in default standby mode)
The base RF400/RF410 in the above example does more receiving and less
transmitting than the remote RF400/RF410 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 RF400/RF410 current drains,
so the calculated values for remote and base RF400/RF410s 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
=
=
Ч
=