Table 9-1: Symptom, cause, and solutions
Symptom
Possible cause
Solution
All CS650 output values read 0 No SDI12Recorder instruction
in data logger program
Conditional statement that
triggers reading is not
evaluating as true
Add SDI12Recorder instruction
to data logger program
Check logic of conditional
statement that triggers
readings
All values read NAN. First value
reads NAN and all other values
read 0 or never change from
one measurement to another
CS650 SDI-12 address does not
match address specified in
data logger program
CS650 green wire not attached
to SDI port specified in data
logger program
CS650 not being powered
Change sensor address or
modify program so that they
match
Connect wire to correct control
port or modify program to
match wiring
Make sure red wire is
connected to 12V or SW12V
and black wire to G
If using SW12 to power sensor,
make sure red wire is
connected and data logger
program switches SW12 on
VWC reading is 9999999
Soil bulk permittivity is outside
sensor operational range
Modify program to collect
permittivity value and try soil
specific calibration
EC reading is 9999999
Soil bulk electrical conductivity
is outside sensor operational
range
If using CS650, try CS655
Readings erratic, including
NAN and 9999999
Multiple sensors with same
SDI-12 address sharing same
control port
Give sensors unique addresses
or put on separate control
ports
CS650 and CS655 Water Content Reflectometers
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