Campbell Scientific ET107 Evapotranspiration Monitoring Station - Manual (Page 50)

ET107 Weather Station
2) Mount the surge protector box to a flat surface within 5 feet of the PC’s
serial port. Ground the center terminal to an earth (or building) ground
using the 14 AWG wire.
3) Connect the 5-foot patch cable from the surge box to the Rad Modem.
Fasten the cable to the strain relief tab with a cable tie. Connect the Rad to
the PC’s serial port with the 9-to-25 pin serial cable.
4) Route the user-supplied cable from the remote splice to the surge
protector. Connect it and the 5-foot patch cable to the surge protector.
FIGURE 2-29. Short-haul modem wiring diagram
2.5.4 RF450 900 MHz, 1 Watt Spread Spectrum Radio
The RF450 is a license free 1 watt spread spectrum radio. Communication is
strictly line-of-sight. Communication distance is dependent on antennas,
cabling, and terrain (please note that line-of-sight obstructions and RF
interference will affect transmission distance).
2.5.4.1 Power Considerations
AC power is recommended when using RF450 radios with the station. A 10
watt solar panel can be used but days without sunlight and winter months with
little sunlight should be considered. The ET107 station comes with a 7 amp-
hour battery that is NOT designed to handle deep discharge. Discharging the
battery below 11 Vdc may require battery replacement. Below are some
examples of power calculations. Battery current consumption is based on
See Figure 2.5-1 for close-up
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