Clock losing time on Allegro 2 or Archer 2
12 Jan 2016
The Archer 2 and Allegro 2 (A2) provide both a processor real-time clock as well as a separate Real-Time Clock (RTC) chip for maintaining date and time to within +/- 3 minutes per month. These clocks are maintained by the main battery of the A2 unit. Even when you perform a proper full Power Off (by selecting it from the menu that appears when holding the Power button for 3 seconds) or a Hard Reset (by holding the Power button for 30 seconds, and then again for 3-5 seconds if needed), it will store the last date and time in the Windows registry. When the unit powers back on, it checks the separate RTC to make sure the processor clock is still in sync, and if not, it will then prompt you to manually set the date and time from the last stored values.
If the battery in the A2 is ever removed or fully drained (not recommended), both clocks will be reset. When the unit powers back on, you will be prompted to manually set the date and time from the last stored values. You should not encounter this as long as the unit is left plugged in every night and weekend as we have always recommended (at least for all Allegro and other later product models).
It is believed that some software applications may be extremely processor intensive and/or fully utilize all available system resources, occasionally freezing the system including the processor clock. This is similar to as listed at the bottom of the following web page.
Other things that could impact the clock (though you would probably know if they were) are mentioned at these web pages.
If you are still unable to account for or resolve a clock issue on a particular A2 unit, then we can certainly evaluate such a unit on a submitted repair order.
For Geonics (EM31, EM31MK2, EM34-3, EM61-MK2, etc.) and Geomar (TrackMaker, RTmap) software programs, every 22 or more days the Windows timer (which starts when OS starts) will reset. If this occurs, when the software time stamps GPS positions with local (Allegro/Archer) timer, a problem can occur due to non-sequential timing. So, every 20 days if this software detects that the system has not been soft Reset at all during that time, the software should prompt you to perform a Reset. If you miss or ignore that prompt, you may encounter such a clock issue.