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tank level
temperature
tide and sea state
turbidity
water velocity
weight of snow and ice on a snow pillow
wind speed and direction
Sutron also offers general purpose interfaces for making analog and digital measurements via SDI-12.
For more information on SDI-12, go to
18.2
Wiring Guidelines
SDI enables you to connect up to 10 sensors with as many as many as 9 parameters each. The interface is
implemented using three wires: data, ground, and +12V. The ground conductor of the SDI interface line
should be large enough to keep the voltage drop between the data recorder and the sensor to less than
0.5 volts during the maximum sensor current drain. Failure to observe this specification will cause bad
communications and/or bad data. The maximum current used on the +12V line should not exceed 0.5
amps at any time.
18.3
Connector
The connector type is not part of the SDI specification. Make sure to connect all three lines: SDI-12 Data,
SDI-12 PWR, and GND. Multiple sensors can be connected to a single connector.
18.4
Setup of SDI sensors
Each SDI-12 sensor has an address from 0 to 9. This address differentiates one sensor from another. Most
sensors are factory default set to address zero (0). If/when interfacing more than one sensor, each sensor
must be assigned a unique address. This is normally done by setting dip switches on the sensor or by
software commands. Failure to set unique addresses for each sensor will result in failure of the
communications interface (i.e.
no data logged). Consult the sensor manufacturer’s data for information on
your particular sensor(s).
When setting up multiple SDI-12 sensors, connect one sensor at a time. Once a new sensor is connected,
you must give it a unique address. To do so, either use LinkComm or the command line. Type SDI-12 FIND
to detect new sensors. Once a sensor is found, change its address by typing SDI xAy!, where x is the old
address, A is A, and y the new address. For example, SDI 0A1! will change the address from 0 to 1.
When getting more than one parameter from a single sensor, be sure to set the measurement schedules
the same. When the station finds multiple parameters from a single sensor (same address), it will only
issue a measurement of the sensor once, then read each of the parameters from the one measurement.
Summary of Contents for SUTRON XLINK 100
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