SDI-12
SDI-12 is a digital communication interface commonly used with environmental, hydrology, agriculture and weather sensors.
YuDash data loggers with SDI-12 support can communicate with compatible SDI-12 sensors, acquire multiple variables from a sensor and map the returned values to user-defined parameter names.
Typical applications include:
Soil moisture and soil temperature
Water level and hydrology sensors
Water-quality instruments
Meteorological sensors
Agriculture and irrigation monitoring
Multi-parameter environmental probes
On supported FELYX models, SDI-12 is available as a dedicated sensor interface.
How SDI-12 works in YuDash devices
A typical configuration consists of:
SDI-12 Sensor → YuDash Data Logger → Variable Mapping → Data Logging / Cloud / Local Monitoring
Each connected sensor is assigned an SDI-12 address. The YuDash device sends the configured measurement command to the sensor and reads the returned measurement values.
The individual returned values can then be assigned meaningful variable names.
SDI-12 Sensor Connection
Connect the SDI-12 sensor to the supported YuDash device before starting configuration.
A typical SDI-12 connection includes:
Power — sensor supply from the device, where supported
GND — common ground
SDI — SDI-12 data line
The example below shows an SDI-12 soil-moisture sensor connected to a YuDash FELYX data logger.
Always refer to the sensor datasheet and the product wiring guide for the exact terminal assignment, supply requirement, and wire colors.
Configuring an SDI-12 Sensor
Add or select a sensor
In the SDI-12 Sensor Manager, add a new sensor or select an existing sensor from the list.
Configure the sensor settings:
Address — SDI-12 address assigned to the sensor.
Label — optional descriptive name for the sensor.
Measure Cmd — measurement command used to request data from the sensor.
M!is the standard measurement command shown in this example.sdi12VarCnt — optional variable-count setting. Leave blank when all returned variables are to be processed.
Under Variable Mapping, map the values returned by the sensor to YuDash variables.
For each variable, configure:
Var Name — name used for the parameter in YuDash.
Factor — scaling multiplier; normally
1when no additional scaling is required.Unit — engineering unit, where required.
Description — optional description of the parameter.
The IDX represents the sequence position of the value returned by the sensor.
In the example shown, one SDI-12 sensor returns five parameters:
Volumetric water content
Soil temperature
Relative permittivity
Bulk EC
Pore water EC
Select Save & Close after completing the sensor configuration.
Verify SDI-12 Data
After the device restarts, open the Live Dashboard.
The configured SDI-12 variables should appear under Sensor Data with their current values.
The Device Run Status can also be used to confirm communication with the sensor. During normal operation, the log will show the SDI-12 sequence, including sensor detection, measurement, reading and processing of the returned values.
This provides a quick way to verify that:
Sensor detected → Measurement completed → Values read → Variables available
SDI-12 Tool
YuDash also provides an SDI-12 Tool for sensor commissioning, testing and troubleshooting. It can be used independently to communicate with SDI-12 sensors before or during field installation.
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