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Dear customers and partners,

today's newsletter contains important information for you regarding the upcoming GPS week rollover.

Why do we contact you regarding this topic?

Older, obsolete GPS receivers may possibly not handle the GPS week rollover on April 6, 2019, or may achieve the end of their operational life until December 31, 2018.

Wrong / implausible system time as well as GPS reception failure may occur. Both effects are irreversible for affected GPS receivers.

Is my hopf-application affected?

The following hopf GPS products are generally NOT affected:

• System 6844(RC)
• Module 8024/GPS
• Time Server 8029NTS/GPS
• Time Server 8029HEPTA
• Time Server 8030NTS/GPS
• Time Server 8030HEPTA

Applications delivered after Q3/2005 are normally also NOT affected.

For affected applications it is possible to exchange the mounted, obsolete GPS receiver against a current GPS receiver. This can easily be done by the customer at site. A brief user's instruction guide will be available upon delivery of the current GPS receiver. For modular systems (e.g. System 6842 / 7001 / 7001RC) the GPS control card can alternatively be changed. We are providing you with the following specific contact form to check if your hopf-application is affected.

Please understand that a check of older applications delivered before Q3/2005 is only possible via this contact form and only if all mandatory fields of the form are correctly and completely filled out.

Why does the GPS week rollover occur?

NAVSTAR GPS-system has its own date calculating scheme, based on counting weeks. The data signal sent by the GPS satellites contains the week number in the form of a 10bit variable. Based on this variable the GPS receiver calculates the correct date. The limitation to 10bit consequently limits the number of viewable weeks to 1024 maximum. After 1024 weeks the numerator is resetted to zero. This is called week rollover.

The very first beginning of week counting happened on January 6, 1980. The first week rollover took place an August 21, 1999. The next GPS week rollover will occur on April 6, 2019.

Your team of hopf Elektronik GmbH