How to Output Digital Depth

How do I output digital depth information?

The digital depth is output from any Matrix, 700, 800, 900, 1100 or HELIX Series unit over the NMEA interface once every second. This can be directed to a personal computer or laptop computer for real time depth recording. The AS PC 3 cable accessories are required to connect the computer to the accessory connector on the Fishing System. We recommend using Hyperterminal or Tera Term on the PC to capture the data. Hyperterminal is common on most older Windows based PC's. Tera Term can be found on Windows XP or higher. It can usually be found by clicking on the Start button and selecting Programs>Accessories>Communications>

Note: The default setting for NMEA output on your Fishing System unit is OFF. To turn the NMEA output ON, press the MENU key twice to bring up the main menu system. Use the RIGHT cursor key to select the Setup tab. Use the DOWN cursor key to select the User Mode menu. Use the RIGHT cursor key to select Advanced. Use the DOWN cursor key to select the NMEA Output menu at the bottom of the list. Use the RIGHT cursor key to select ON. Use the EXIT key to exit the menu system.

These programs will capture the NMEA messages, called sentences, as they are output from the Matrix and display them on the computer screen. Hyperterminal or Tera Term can also be setup up to save the captured sentences to a text file. You can then use Microsoft Excel to read in this text file using the comma delineated input feature to separate out the depth and offset values.

NMEA Sentence

The following NMEA Sentences are output from the units:

  • DPT - Depth
  • MTW - Water Temperature
  • GLL(*) - Geographic Position (latitude/longitude)
  • GGA(*) - GPS Fix Data
  • RMC(*) - GNSS Data
  • VTG(*) - Course Over Ground and Ground Speed
  • ZDA(*) - Time and Date
  • XTE(*) - Measured Cross-Track Error (Only outputs while navigating)
  • APB(*) - Autopilot Heading/Track Controller (Only outputs while navigating)

(*) - These sentences are related to GPS and do not contain any information unless a GPS receiver (external or internal) is connected to the Humminbird unit.

If a GPS receiver is connected to the Humminbird unit, then other NMEA sentences containing navigation and waypoint information will also be output by the Humminbird Unit. For more information on the NMEA0183 specification, consult the www.nmea.org website.

Digital Depth

is embedded in the DPT sentence. Its format is as follows:
$INDPT,d.d,o.o*hh<CR><LF
Where:

  • d.d is the decimal depth value in meters relative to the transducer
  • o.o is an offset from the transducer to the surface. This Depth Offset can be programmed into the Matrix unit under the advanced main menu system. (see Matrix User's Manual for more details)
  • hh is an automatically generated checksum for communications error checking <CR><LF> - stands for "carriage return" and "line feed" which indicates the end of the transmitted sentence.

Water Temperature

Water Temperature is embedded in the MTW sentence. Its format is as follows:
$INMTW,t.t,C*hh<CR><LF>
Where:

  • t.t is the decimal temperature value in Celsius degrees
  • hh is an automatically generated checksum for communications error checking <CR><LF> - stands for "carriage return" and "line feed" which indicates the end of the transmitted sentence.

Note: The NMEA0183 standard requires that digital depth and water temperature be reported in metric units. It is left up to the user to convert to imperial units if desired.

To use Tera Terminal follow the steps below:

  1. Download and install TeraTerm http://logmett.com/freeware/TeraTerm.php
  2. Download and install driver http://www.ftdichip.com/Drivers/VCP.htm
  3. Open TeraTerm
  4. Click the serial port radio button
  5. Use the drop down box to select the correct serial port. The AS-PC3 cable will typically say USB to Serial Converter.
  6. In the Setup menu select Terminal and Select the Local Echo box
  7. In the Setup menu select Serial Port
    1. Change the Baud Rate to 4800.
    2. Set Data to 8 Bit
    3. Set Parity to none
    4. Set Stop to 1 bit
    5. Set Flow Control to none
  8. In the Setup menu select Save Setup to save the Tera Term configuration to your computer. You can use this file in the future to avoid Steps 4-6.
  9. Enable NMEA0183 on your Humminbird Control Head. You should begin to see the NMEA0183 data appearing on the computer screen.
  10. To save the NMEA0183 data to a text file, in the File menu select Log.
    1. Provide a filename and location to save the file.
    2. Adjust any logging options at the bottom (Append, Plain Text, etc.)
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