FURUNO Singapore News & Events

“GPS Rollover on 20th December 2020 for FELCOM15/16, FELCOM70, FA-100/R and GP-310B”

31 March 2020

We would like to inform valued customers and users of FURUNO GPS marine products of the GPS week number rollover occurring on 20th December 2020.

This happens because the GPS system calculates time by counting to 1023 weeks, after which, the count resets to zero. This is called the “GPS Week Number Rollover”. Subsequent erroneous data information on the GPS receiver clock may result in position instability, causing position errors, including failure of the GPS position acquisition etc.

List of Affected Equipment

Rollover Occurrence Date: 20th December 2020



S/N before 3533-9370


S/N before 3534-2755

Rollover will not affect communication function, but the following my occur:

       – Date will not be automatically updated.

       – Time of position dates on interval reports such as the SSAS and   VMS Data Report will be incorrect.


Rollover will not affect communication function, but the dates on communication logs will be incorrect.

Note: The service of Inmarsat F will terminate on 30th Nov 2020.

FA-100/RRollover will not affect communication function, but it will affect the dates of the AIS internal system (internal GPS, display of own ship dynamic data, logs transmitted, messages received, alarm logs and power on/off logs).


S/N before 3453-5687

No calculation of the position occurs.



  • To update the software for FELCOM15/16 to software 3.11 or 5.05.
  • For models AIS FA-100, a retrofit to FA-170 is recommended.
  • Similarly, for models F77 FELCOM70, Non-IMO GPS GP-310B, a retrofit is recommended.



(i) Flowchart to check if software upgrade is necessary

(ii) How to check GPS Port

Contact us for more information:

For Retrofits: salesgrp@furuno.sg

For Software Upgrade: sdc@furuno.sg


Click here for more details.