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Drivers Manual

NMEA (DPT-DBT-DBS) (With Annotation) - 01


Driver for decoding water depths from an echosounder providing a NMEA DPT, DBT or DBS telegram, or from an echosouder outputtting a Simrad ping based ASCII telegram, such as a Simrad EA 400 system.

The driver will decode the water depth reading (in meters) and the bottom condition (as quality indicator), if available in case of a Simrad ASCII telegram.
The driver can also output a NMEA annotation telegram.

Driver Information

Driver NMEA (With Annotation)
Simrad (With Annotation) 
Interface Type Serial Driver Class Type Terminated
UTC Driver (question) No Input / Output Input and Output Executable DrvAnnotate.exe
Related Systems
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Decoding Notes

Driver will decode the x.x field from a NMEA DPT telegram or the y.y field from a NMEA DBT or DBS telegram.
Signal quality indicator is always 1 for a water depth decoded from a valid NMEA telegram.

Driver will decode the xxxx.xx field from the Simrad ASCII telegrams.
The zzz field is decoded as signal quality indicator.
The time field in the Simrad ASCII telegram is disregarded by the Qinsy driver.

Interfacing Notes

It is important that the wiring of the cable between the echosounder and the COM port is bi-directional, i.e. allows two-way data transfer, so that the Qinsy driver can send the annotation telegrams, if selected.

System Configuration

The NMEA telegrams can only provide depth information from one channel.
With the Simrad EA 400 echosounder system, which channel is used, is selected in the depth output dialog box, whereas the telegram type to be transmitted (DPT, DBT, DBS, Simrad, Atlas Deso 25) is selected in the same dialog box.
For the Simrad ASCII output telegram, one telegram is exported from each echosounder channel (limited to 3).

Database Setup

Select the "NMEA (DPT,DBT,DBS) (With Annotation)" driver to decode any incoming NMEA DPT, DBT and/or DBS telegrams.
Select the "Simrad ASCII (With Annotation)" to decode a so-called Simrad ping based ASCII telegram for a certain channel.


Driver with user-interface, so settings can be changed online, by clicking on system button on task bar:

The driver window displays the user selections. Notice that decoded values are not shown in the display.


Use Settings – Annotation to select the annotation format and output data content.
Use Options – Direct Annotation to send a fix mark and/or annotation comment directly to the echosounder or side-scan sonar.

Use Context Sensitive Help in the Annotation Dialog to get more information about each specific item.


Simrad annotation is the same as NMEA annotation. At present, the checksum field is always added.

Drivers IO Notes

Command line parameter "NMEA" will decode any DPT, DBT and/or DBS telegram.
Parameter "SIMRAD" will decode the Simrad ASCII telegram that starts with the "D#" combination for the selected channel.