Furuno GPS Rollback Week

Old 08-02-2013, 11:56 AM
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Default Furuno GPS Rollback Week

Here is an announcement from Furuno that we just received and thought everyone with these products should know.

On August 11, 2013 the internal date calculation of the GB-94 and GN-77NNCC-N GPS receivers will roll back to December 26, 1993. This is what is referred to as "GPS Week Number Rollover". This is similar to the rollover that affected a number of our products a few years ago.

These GPS receivers were used in a number of Furuno products (see below). They were replaced several years ago and are no longer in use, so there are no current products that will be affected by the GPS Week Number Rollover.

The list of products that will be affected are as follows:

This GPS Week Number Rollover will not affect the accuracy of the position, course or speed data of the listed product(s). However, the date information will NOT BE CORRECT.

In applications where this GPS receiver is being used solely for providing position/course/speed data and the date information is ignored or not relevant, THERE WILL NOT BE A PROBLEM and this issue may not even be noticed!

However, if the GPS receiver is integrated into a data-collecting system or connected to equipment where the accuracy of the date is critical, a problem will likely arise because the date information may be processed incorrectly.

Examples of equipment applications where this GPS Week Number Rollover may pose a problem:
GMDSS Radio Stations transmitting critical messages such as distress alerts.
Ship Security & Alert System (SSAS) transmitting distress alerts.
Vessel Monitoring System (VMS) automatically transmitting updated position, course and speed data at regular intervals.
The reason behind the GPS Week Number Rollover:
GPS systems calculate the date by counting the number of weeks in a 1,023 week cycle. On the evening at the start of the 1,024th week, the GPS week "counter" will roll back, or start over at zero weeks (Time Scale Origin). The result of this is that some GPS receivers may process certain satellite data incorrectly and then provide incorrect date information.

For the GP80 and RS1000A/C, no upgrade is available so the GPS unit will need to be replaced. Please click here for a table of other other models affected by the GPS Week Number Rollover.

GPS Rollover Parts 2013
We apologize for any inconvenience this issue may cause you and we appreciate your understanding. If you have any questions, you may contact a Furuno technician at either our Camas, WA facility 360-834-9300 or our Denton, MD facility 410-479-4420.

Furuno USA, Inc.
threeriversmarine is offline  
Old 08-02-2013, 12:17 PM
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Ahh.... the Furuno GPS expiration date.

Anyone here have those old units that are otherwise working perfectly well, and have any comment on this?

The good news is you still have 8-9 days heads-up warning to buy a new unit.
TTaxi is offline  
Old 08-02-2013, 03:35 PM
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Location: Melbourne, Australia
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GPS rollover is applicable to all manufacturers GPS receivers - not just Furuno.
gdfisher is offline  

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