Posted by: Ger Rietman | June 29, 2015

Many updates in the GPS module of NemaStudio in Version 1.27


New Version 1.27 updates

Version 1.27 of NemaStudio comes with many updates, especially regarding the GPS instrument.

A major update is shown in the image left (click image to enlarge). It show the new GUI change when in Navigate mode.

As you may know in this mode you can ‘sail’ a pre-set route, defined in a so called $GPWPL file. The GPS module will then ‘sail’ from Waypoint to Waypoint, as defined in the file. You must navigate and keep the boat on track with the controls in the Object Control Center.

In Navigate Mode you have the option to send two extra NMEA 0183 sentences: XTE and RMB. Before Version 1.27 NemaStudio always has updated the “Destination Closing Velocity” field in the RMB sentence with the value from the Velocity control. This was actually not according the NMEA 0183 specification.

From version 1.27 however NemaStudio is calculating the VMG (Velocity Made Good) and saves this value in the “Destination Closing Velocity” field of the RMB sentence.


How this works is shown by the picture on the left.

Suppose we are following a given route and we are sailing from Waypoint WPn to Waypoint WPn+1.

The further we get off our given track, the Rhumb Line, the lower our relative speed (VMG) will become. At a certain point the relative speed can even get negative.

As set before NemaStudio now saves the VMG in the RMB sentence and is also shown in the GUI, as is the Rhumb Line.

Slave GPS

Also new in Version 1.27 is the possibility to define one or more Slave GPS’s. A slave GPS always has GPS1 as master, so GPS1 always must be active when you want to assign a slave GPS.

NemaStudio127Screenshot2The slave GPS will have all Object Control controls disabled. Course and Velocity are taken from the master, thus GPS1. Also the current position is taken from GPS1.

This way you can simulate you have two or more GPS’s on the vessel, without having to synchronize position, course and speed.

You select the option in the Exec Mode frame.

GPS, other changes and bug fixes

  • From version 1.27 you can, optionally, choose your own Sentence Identifier.
  • A CLR stack overflow Exception situation was corrected,
  • Pos. Update Timer was reset to 1.0 when applying User Tweaked UTC. Corrected.
  • An error in Magnetic Course calculation in the VTG sentence was corrected.

Transducer module

  • The user can now define her/his own Sensor Identification string

Custom module

  • A vertical scroll bar on the sentence input panel was added

Multicast UDP option implemented

NemaStudio now offers also UDP Multicast as an option.


This feature has only be tested to a minimal level, so without routers and other IP hard- or software.

If you are considering using this option I would really like your feedback!

Observe that for UDP Multicast the IP address must be in the range to and that the TimeToLive must be > 0.

Apart from feedback on the UDP Multicast feature I would also like feedback whether you would appreciate implementation of the TAG block in NemaStudio!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s


%d bloggers like this: