B.4
SDI-12
B.4.1 Data logger receives no SDI-12 data
Reason
Solution
The sensor is set to
Measurement trigger
inter-
val
, but the data logger sends a
M!
command,
i.e. the data logger polls data.
If data are polled from the sensor,
Measurement
interval
must be set to
SDI-12/RS485
.
The sensor is set to
Measurement trigger
SDI-
12/RS485
, but the data logger sends an
R!
com-
mand, i.e. the sensor pushes data.
If the sensor pushes data,
Measurement interval
must be set to
interval
.
Multiple sensors are connected to the data log-
ger and two or more sensors have the same
SDI-12 address.
If multiple sensors are connected to the same
data logger, each sensor must be assigned a
unique SDI-12 address.
Some third-party sensors may not issue a ser-
vice request when they have completed a meas-
urement.
If a sensor does not issue a service request after
a measurement, a
C!
command instead of a
M!
command must be sent to start a measurement.
Otherwise the data logger runs into a timeout or
is waiting indefinitely for a service request.
B.4.2 The USH-9 is not detected by a SDI-12 master device
Reason
Solution
The USH-9 and the SDI-12 master have dif-
ferent grounds.
Verify that the USH-9 and the SDI-12 master are
connected by a ground (GND) wire.
A
p
p
en
d
ix
B
T
ro
u
b
le
sh
o
o
ti
n
g
Manual
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