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iXBlue GAPS (PTSAX-PTSAY) (No PV Check) - 02


Driver to decode the absolute or relative positioning message from an iXSea GAPS (Global Acoustic Positioning System), a fully integrated (INS and GPS) portable USBL system.

Two versions of the driver are available: a Serial version and a Network version (UDP). The internal workings of the drivers are the same except for the data reception.

This section will describe how to decode the relative positioning message.
To decode the absolute positioning message, see the 12 - iXSea GAPS ($PTSAG Message)

Take careful notice of the explanation about entering slot numbers in your template database setup, see tab page Qinsy Config.

Driver Information


iXSea GAPS (PTSAG Message)

Interface Type Serial  Driver Class Type Terminated <LF> 
UTC Driver (question) No Input / Output Input  Executable DrvIxseaGaps.exe 
Related Systems
Related Pages

Decoding Notes

  • Date and time from the message may be decoded, but only if you are sure that this is UTC time AND that Qinsy also uses PPS. In that case you have to select the driver with the "With UTC"-option. 
    Otherwise the data will be time stamped when it is received at the I/O port.
  • Data is only accepted when the Position Validity (field 9) indicates an 'F'. 
    If you want to overrule this position validity check, and if you want to accept data when Position Validity check (field 9) indicates '0', then select the driver with the "No PV Check"-option. 
    Quality indicators other than 'F' and '0' are not decoded!
    When the position validity is valid ('F'), then the quality indicators for USBL XYZ observations are zero, and can be monitored using an Observation Physics Display. 
    When the position validity is not valid ('0'), then the quality indicators for USBL XYZ observations will be -1.
  • The Frame number (field 1), the Depth Validity (field 11) and the Sensor depth (field 12) are not decoded.
    However, the frame number is stored for debug purposes as differential age value for Positioning System, which can be monitored using a Positioning System Display.

Interfacing Notes

No specific interfacing or configuring recommendations. The driver does not send any commands to the GAPS.

If you use the network driver, data should come in via a UDP network connection.

For MOXA NPort Server Pro (8/16 Ports Serial Device Server ) users please look up the example settings described in iXSea GAPS ($PTSAG)  Message.

Database Setup

Add a USBL System to your template and select the driver "iXSea  GAPS ($PTSAX/$PTSAY Message)"

Slot Numbers

The slot numbers on the USBL Targets wizard page must be the actual Transponder # (1 to 128, for Qincy 9.5.2 or older, or 1 to 2147483647 for Qincy 9.5.3 or newer), plus a character 'X' or 'Y' added, in order to make a distinction between decoding targets from the PTSAX or PTSAY message.
Note: use upper case character 'X' or 'Y', and not 'x' or 'y'.

For example, enter slot number '2Y' if you want to decode data from transponder 2 of the PTSAY message.

Or, enter slot number '3X' if you want to decode data from transponder 3 of the PTSAX message.
(If you omit the 'X' or 'Y' character, only data for a PTSAX message will be decoded).

Don't forget to set the Heading field, in Database Setup - USBL System Parameters - Corrections applied to data, to "Raw gyro" or "Corrected gyro" when using the $PTSAY format.

Applying roll and pitch automatically means that the data is corrected for the roll and pitch movement; the transducer misalignment for pitch and roll still needs to be entered.

Additional Information


  • Added support for new cmdline NOPVC, in order to accept data with a non-valid position validity (field 9). 
    See Decoding Notes for more information about this