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July 18, 2024

For customers using the Class B AIS ZSA-1000
~ Important Notice Regarding the " GPS Week Number Rollover " (July 6, 2025) ~

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We would like to inform you that the Class B AIS ZSA-1000※1 will experience a phenomenon called "GPS Week Number Rollover"※2 on July 6, 2025.

This rollover phenomenon causes the date, month, and day displayed on the device to revert to the starting date (past year, month, and day). Incorrect display or incorrect output of the date may interfere with positioning operation, equipment operation, and functions. The effect on the receiver of the transmitted data is unknown.

We recommend our customers currently using the ZSA-1000 to consider upgrading to the latest model, the ZSA-2000. The ZSA-2000 is a state-of-the-art Class B AIS transponder that complies with international standards such as ITU and IEC. It offers a compact, cost-effective, highly reliable, and robust performance for a wide range of applications including safe navigation and vessel monitoring. Explore the enhanced features and improved performance with the ZSA-2000.

  • ※1 ClassB AIS (ZSA-1000) has been superseded by ZSA-2000 model.
  • ※2 What is "GPS Rollover"?
    •  The GPS week number rollover is a phenomenon that happens every 1,024 weeks, which is about 19.6 years. The Global Positioning System (GPS) broadcasts a date, including a week number counter that is stored in only ten binary digits, whose range is therefore 0–1,023. After 1,023, an integer overflow causes the internal value to roll over, changing to zero again.