[time-nuts] Lucent KS-24361 REF 0 standalone
thomas at petig.eu
Tue Feb 7 17:39:57 EST 2017
Thank you for your reply.
As always, the solution appears after sending the mail on the list. I
send a wrong character for terminating the message and therefore the REF
0 was confused when the message ends (it expected 0x0D 0x0A, but got
0x0D 0xA0 from me).
It seems that in pForth, pr_gps_debug will count this as frame error.
Regarding my setup, I am sending the Oncore messages from Python via a
USB cable. I just trigger the Python script on the PPS, I don't read the
actual what the skytraq sends. It seems the REF 0 is happy with the
timing of my Oncore messages.
On Mon, Feb 06, 2017 at 03:40:23PM -0500, Bob Camp wrote:
> The only serial dialog between the two units is a repeat of the output of the
> GPS module. My guess is that there is some subtle difference between
> the Oncore data and they skytraq….
> > On Feb 6, 2017, at 1:23 PM, Thomas Petig <thomas at petig.eu> wrote:
> > Hi everyone,
> > I am currently trying to repeat previous work of members of this list in
> > convincing the REF 0, to run standalone with a given 1PPS signal from a
> > gps. Similar to:
> > https://syncchannel.blogspot.se/2015/08/standalone-operation-of-lucent-ks-24361.html
> > I am using a skytraq gps with 100ms, 74AC04 for inverting and level
> > shifting and I added the jumper wires on J5. I simulate the Oncore
> > messages with a python script using a usb->uart cable and triggering on
> > the 1PPS pulse on the CTS line. I am sending @@Ea, @@En, @@Bb, @@Ap,
> > @@Aw, @@Ag, @@At, @@Az, @@Bj, @@Bo with a delay of 75 ms, as suggested
> > in the blog above:
> > https://github.com/thpe/oncore/blob/master/oncore_emu.py
> > Surprisingly, I have a constant delay of 0.8 ms, and only a jitter of
> > +/-0.1 ms for the oncore messages compared to the pulse on the CTS line.
> > Short everything is working and if I force external 1PPS usage it locks
> > to it (NO GPS light goes off). Using pForth:
> > 1 force_ext_1pps
> > 1 force_gps_1pps
> > But, it does not do it on its own, since it ignores the tracking mode
> > for the satellites and, I guess after reading the Z3801A manual,
> > therefore it claims the GPS 1PPS signal as invalid. E.g., for the entry
> > with @@Ea:
> > 0x02, 0x08, 0xFF, 0x82
> > meaning satellite 2 in mode 8 (used for positioning) it assumes mode 0.
> > The other values, like signal strength 0xFF and channel status 0x82 are
> > taken, even if I change them to something else. The mode value is
> > ignored no matter what it says.
> > In the attached files on sees that "GPS 1PPS Invalid: not tracking", and
> > the mode of the is 0. I forced it to use the external 1PPS signal.
> > So, the question what tiny detail did I miss while reading the mailing
> > list archive and those blogs on how to set the REF 0 up for standalone
> > operation just using the Oncore messages?
> > Does someone has dump of the communication between REF 1 and
> > REF 0, until the REF 0 is happy (I don't have a REF 1)?
> > Regards,
> > Thomas
> > DK6KD
> > SA6CID
> > <pstat.txt><print_stat.txt>_______________________________________________
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