[App_rpt-users] RTCM voter problem - SOLVED

[Joe Leikhim]

According to the original documentation for the first generation X1 is a 
SER3418-ND 9.60MHz 18pf 30ppm.

So 9.6 x (+/-) 30 = +/- 288 Hz.

My question is If the same processor is doing the A/D conversion AND 
checking the number of samples/second why would there be a discrepancy 
regardless of the timing offset? Or is the error at the receiving end??



On 4/9/2016 2:16 PM, James Cizek wrote:
> Sure Willem,  in voter.c, the stock line is:
>
> if ((samplecnt >= 7999) && (samplecnt <= 8001))
>
> it needs to be changed to something like:
>
> if ((samplecnt >= 7999) && (samplecnt <= 8003 ))
>
> That was just enough to make my first RTCM work.  I've had a chance 
> now to check a few more of my RTCMs on the bench this morning and the 
> crystal frequencies are kind of all over.  The next one I had on the 
> bench was 5.2Khz fast.  The above code was still not enough to fix it 
> (as would be expected) so it looks like the quality control on 
> whatever manufacturer that crystal is, isn't very good (or a low 
> tolerance crystal is being used).  I am going to pursue crystal 
> replacement to get a highly accurate, stable, on-frequency crystal in 
> there as my first choice.  Changing the firmware 5 different times 
> doesn't seem like the right answer.
>
> Jim put that sanity check in there for a reason.  Working around it 
> *may* allow the device to work, but to me, it seems getting the 
> hardware operating the way it was supposed to originally is the better 
> answer.  I will follow up with Micro-node and let you all know how it 
> goes.
>
> Thanks.
>
> James
> KI0KN
>
> On Sat, Apr 9, 2016 at 9:05 AM, Willem Schreuder <willem at prinmath.com 
> <mailto:willem at prinmath.com>> wrote:
>
>     On Sat, 9 Apr 2016, James Cizek wrote:
>
>         Jim helped adjust the code to be more tolerant of the sampling
>         error and my whole system instantly worked.
>
>
>     Could you please share the code adjustment for future reference.
>
>     ================================================================
>     Dr. Willem A. Schreuder,  President,  Principia Mathematica
>     Address:  445 Union Blvd, Suite 230,  Lakewood, CO  80228, USA
>     Tel: (303) 716-3573 <tel:%28303%29%20716-3573>   Fax: (303)
>     716-3575 <tel:%28303%29%20716-3575>
>     WWW: www.prinmath.com <http://www.prinmath.com>   Email:
>     Willem.Schreuder at prinmath.com <mailto:Willem.Schreuder at prinmath.com>
>
>
>
>
> _______________________________________________
> App_rpt-users mailing list
> App_rpt-users at ohnosec.org
> http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-users
>
> To unsubscribe from this list please visit http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-users and scroll down to the bottom of the page. Enter your email address and press the "Unsubscribe or edit options button"
> You do not need a password to unsubscribe, you can do it via email confirmation. If you have trouble unsubscribing, please send a message to the list detailing the problem.

-- 
Joe Leikhim


Leikhim and Associates

Communications Consultants

Oviedo, Florida

JLeikhim at Leikhim.com

407-982-0446

WWW.LEIKHIM.COM

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.keekles.org/pipermail/app_rpt-users/attachments/20160409/9dc29b1b/attachment.html>