About the Actisense DST-2 and its DST Smart Calibration Utility

Article HD25106, September 8, 2015

Actisense DST-2 features and notes on the DST Smart Calibration Utility.


 

Analogue to Digital Conversion using the Actisense DST-2

Overview points about DST-2 module

  • Depth transducers : 3-wire piezo-electric crystal connection type, outputs NMEA 0183 sentences DBT & DPT.
  • Speed transducers : 3-wire hall-effect paddle-wheel connection type, outputs NMEA 0183 sentences VHW & VLW, but only after detection (of at least three pulses from the paddlewheel after power-up). Once detected, any periods that the paddle-wheel is stationary for will be correctly communicated as a zero speed in VHW.
  • Temperature transducer : 2-wire thermistor connection type, outputs NMEA 0183 sentence MTW, but only after detection.
  • Only outputting Speed and Temperature data after detection prevents confusing transmissions when a transducer is not connected.
  • The available frequencies of 150, 170 and 200 kHz need to match the frequency of the Depth transducer.
  • Flash upgradeable to allow in-the-field updates via ActiPatch.
  • Comprehensive Calibration Utility that allows the DST-2 to be calibrated to work with a large range of transducers.

DST Smart Calibration Utility Usage

  • Connect a computer's USB port to the DST-2 via Actisense USG-1 or a similar USB to device connector.
  • In the Smart Calibration Utility, select the virtual COM port receiving data from the DST-2. If available, a COM port to an NMEA 0183 GPS source is recommended when calibrating a speed transducer since the GPS data can be used to automatically build up a speed correction curve.
  • The bottom section that displays the NMEA 0183 data coming from each open COM port is visible on all tabs.
  • The Depth tab displays the current depth values received from the DST-2 and also offers the option to specify a Depth Offset either as a positive Depth Below Surface offset or as a negative Depth Below Keel offset.
  • The Speed tab displays the current speed calibration curve and offers the options to specify up to a 10-point speed calibration curve. As already touched on, this 10-point curve can be auto-calculated based on GPS data.
  • The Temperature tab displays the current temperature value and offers the option to specify a temperature offset to correct basic errors in the chosen thermistor transducer.
  • The GPS and Reference tabs are display helpful information.
  • The Tools tab allows the user to understand what NMEA 0183 sentences are currently coming from the DST-2 and GPS, plus it offers a convenient method of recording the NMEA 0183 data to a file.

Tabs of the Software

DST Calibration Connection tab

DST Calibration Depth tab

DST Calibration Speed tab

DST Calibration Temperature tab

DST Calibration Tools tab