[time-nuts] Tymserve 2100 thinks it's 1995?

Tom Van Baak tvb at LeapSecond.com
Tue May 5 17:58:58 UTC 2015


Hi Sean,

Thanks much for that information.
And now I guess we can't blame Trimble either since their 15-year old Ace documentation [1] says:

----
    ACE III GPS
    System Designer Reference Manual
    Part Number: 41265-00
    Revision: A
    Date: June 2000
    Firmware: 8.08
....
    3.5.1 Effect of GPS Week Number Roll-over (WNRO)
    The ACE III GPS module has been designed to handle WNRO, and there are no problems
    with either dates or first fix after WNRO through the year 2015.
....
    Note  GPS Week Numbers system, as defined by the ICD200 GPS Specification, occupy
    a range from zero to 1023. The Week Number Roll Over (WNRO) occurs every 1024
    weeks, or approximately every 19 years 8 months. August 1999 was the first roll-over for
    the GPS system since the beginning of GPS time on 06 January 1980.

    Caution  Trimble OEM GPS receivers have reported the true GPS Week Number in TSIP
    messages 0x41 and 0x8F-20 as a number between 0 and 1023. The ACE III GPS outputs
    the Extended GPS Week Number as the absolute number of weeks since the beginning of
    GPS time or 06 January 1980. If the true GPS Week Number is desired, the system
    developer should ignore the extra MSBs of the Extended GPS Week Number and use only
    the 10 LSBs.
----

Does anyone on the list know how well the http://www.heoldesign.com replacement works?

Thanks,
/tvb

[1] http://trl.trimble.com/dscgi/ds.py/Get/File-1883/ace%20iii.pdf


----- Original Message ----- 
From: "Sean Gallagher" <sean at wetstonetech.com>
To: <time-nuts at febo.com>
Sent: Tuesday, May 05, 2015 10:06 AM
Subject: Re: [time-nuts] Tymserve 2100 thinks it's 1995?


> Hi all,
> 
> The problem is not the 2100. It is the Trimble Ace III receivers inside 
> of it. There is a company in France, Heol Design, that makes what is 
> essentially a replacement for the Ace III, they call it an N024 model. I 
> am currently in contact with them to see if their units will correct 
> this issue. I first noticed the problem in the Datum BC635 cards and 
> when I tried to go back to a 2100 is when it was confirmed for me. The 
> French units are about $100 apiece and I'll keep you updated on if they 
> work or not.
> 
> In other 2100 news if you revert the firmware back to it's oldest 
> version (2.something) that is embedded in the 2100 it gets rid of the 1 
> second leap issue. You'll lose quite a few options and functionality 
> like the NIST ACTS connection, which I don't think works anyway, but 
> your time will finally be right again. I did this by beginning the 
> firmware update process and power cycling my machine during it. 
> Basically by screwing it up you can make it better.
> 
> 
> Sean Gallagher




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