My Issues

Drivers Manual

Subsea Telemetry Position - 12

Description

Driver to decode position or heading data which originates from the Subsea telemetry system. Data may hold multiple positions.

The driver is typically used when performing Anchor Handling with the Tug Management System (Output Driver: Tug Manager) of QINSy.

The format followed for the transfer of data in/out using the SubSea Telemetry option is based upon the NMEA 0183 message formats for heading and position.
The NMEA 0183 documentation detailing the standard GGA and HDT messages is appended.

Note that there are several points where the actual message form varies from the standard :

  • The address fields have been altered to reflect the code of the vessel originating the data. The result is that $GPGGA is altered to $Gc where c is the code (0-65535) of the originating vessel, and $HEHDT is altered to $Hc.
  • If the heading and the position are output simultaneously, the <cr><lf> is removed from the end of the $Gc string (leaving the *hh) and the $Hc string is appended to the end with its *hh <cr><lf> is left unchanged.
  • In the output, if any fields are unknown, e.g. Geoid Separation, they are set to 0.
  • The GPS status is interpreted as defined by Sercel (for the NR103/NR203 receivers), not as detailed in the NMEA 0183 document.

Note that the latitude and longitude must be in WGS84.

Serial Mux

The string can be generated by using the program Serial Mux from the QINSy Console.

The Serial Mux Program needs to be fed with an NMEA GGA and HDT string (on multiple or a single COM port) and will then be able to output the Subsea Telemetry string.

Driver Information

Driver Subsea Telemetry Position/Heading Interface Type Serial  Driver Class Type Terminated <LF> 
UTC Driver (question) No Input / Output Input  Executable DrvSubseaTelemetry.exe 
Related Systems
Related Pages



Decoding Notes

Heading is only decoded if a Subsea Telemetry (Heading) driver is defined.

Database Setup

The Subsea Telemetry driver can be used to obtain a position and/or a heading (gyro) reading. Select a different system with its own type for each one of the data types to be decoded.

Be sure to define the same interfacing parameters, including driver description and COM port number and settings, for all of these systems.

Position

  1. Add a "System" of type "Position navigation system" and define the interfacing parameters (equal to the Gyro Compass system);
  2. Add a "Variable Node" for the antenna to the QINSy Database; 
  3. Select receiver position (variable node)
  4. Enter receiver number n. This number is used as a slot number to decode the correct position from the data message.
  5. Select the satellite system and its datum.

Heading

  1. Add a "System" of type "Gyro Compass" and define the interfacing parameters (equal to the Position system);
  2. Select: Bearing (True)
  3. Enter slot number n. This number is used as a slot number to decode the correct heading from the data message.