SDI-12 for the GP2 Data Logger

SDI-12 capability enables a single GP2 logger to handle a very large number of networked SDI-12 sensors


  • Huge additional input capacity for SDI-12 sensors
  • Existing analogue and digital channels fully available
  • Highly flexible logger + sensor networks
  • Free of charge upgrade

Ease of Use

  • Seamless integration into GP2 Program Editor, facilitating construction of sophisticated calculations and other operations from SDI-12 measurements
  • Unusually easy point and click configuration; firmware handles scheduling and issuing commands
  • Real time, on demand readings for diagnostics and reassurance
  • Readings from analogue & SDI-12 sensors combined in same dataset

Program Editor

DeltaLINK 3.2 fully integrates SDI-12 functionality into the GP2 Program Editor.

After entering the SDI-12 address and other SDI-12 measurement details, each measurement can feature in Recordings, Custom Formulas, Conditions and Scripts – in exactly the same manner as conventional analogue and digital measurements, and without further reference to SDI-12 commands or measurement timings.

Third-party SDI-12 sensors are also supported.

Upgrading GP2s to SDI-12

GP2s supplied before March 2016 were not SDI-12 enabled.

To upgrade to SDI-12 simply install DeltaLINK 3.2 software (incorporating firmware 2.10) – which is downloadable from our Product Resources section.

Please see below for details of the SDI-12 Sensor Library download.


The GP2 firmware takes care of scheduling (including power switching) and issuing the necessary commands to ensure that results are available for the program to process when required.

DeltaLINK’s ‘Read Now’ feature provides additional ad-hoc readings, in real time and on demand, for commissioning and diagnostic use – and for reassurance that an installation is functioning as intended.

Sensor Library

An SDI-12 sensor library resource containing pre-configured SDI-12 sensor configurations and installation notes for widely used SDI-12 sensors (titled: DeltaLINK SDI-12 SENSOR LIBRARY) is available to download from our Product Resources section.

When imported into DeltaLINK, ready-configured SDI-12 measurements can be easily added to a program with a single point and click menu selection.

The SDI-12 library will be continuously updated – please enquire or submit a request if a sensor of interest is not listed. Users who wish to utilise the full flexibility of SDI-12 devices can generically configure each SDI-12 measurement parameter, and an SDI-12 Transparent Mode terminal is provided for directly issuing SDI-12 commands – as required for setting the SDI-12 address, and also for advanced configuration operations such as using SDI-12 extended commands.

Cables and Connectors

A field-attachable connector for SDI-12 interconnects with the rugged Delta-T M12 5-way sensor/RS232 cabling system. The interchangeable extension cables and T-connectors allow an SDI-12 bus to be easily assembled – and also disassembled when diagnosing the cause of SDI-12 bus operation faults. The GP2 is compliant with SDI-12 Specification Version 1.3.

The GP2 provides a regulated +12 V, 0.5 A supply, which is switched to optimise power consumption.

SDI-12 Profile Probes

The SDI-12 enabled GP2 is the natural data logger of choice for the SDI-12 version of the PR2 Profile Probe. Up to 50 SDI-12 PR2/6 Profile Probes, or up to 62 SDI-12 PR2/4s, can be connected to a single GP2 SDI-12 Data Logger (subject to cable length and power requirements). In addition to SDI-12 inputs, the GP2 can log 12 analog channels.

Learn more about the PR2 Profile Probe SDI-12 here.

WET150 Multi-Parameter Soil Sensors

The GP2 Data Logger is also a perfect partner for the WET150 Multi Parameter Soil Sensor – enabling networks of
up to 62 WET150s per single GP2 (see GP2 manual for details).

Learn more about the WET150 Soil Sensor here.


More information:

GP2 Data Logger Data Sheet.

GP2 User Manual.

View GP2 Data Logger main page