[time-nuts] Lucent KS-24361 REF 0 standalone
Thomas Petig
thomas at petig.eu
Mon Feb 6 18:23:23 UTC 2017
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
-------------- next part --------------
--------------------------- Primary Receiver Status ---------------------------
SYNCHRONIZATION ............................................. [ Outputs Valid ]
SmartClock Mode ___________________________ Reference Outputs _______________
>> Locked to GPS TFOM 3 FFOM 0
Recovery 1PPS TI +10.0 ns relative to GPS
Holdover HOLD THR 1.000 us
Power-up Holdover Uncertainty ____________
Predict 2.0 us/initial 24 hrs
ACQUISITION ................................................ [ GPS 1PPS Valid ]
Tracking: 0 ____ Not Tracking: 10 _______ Time ____________________________
PRN El Az PRN El Az GPS 00:09:07 01 Jan 1998
* 2 80 16 17 32 5 GPS 1PPS Invalid: not tracking
* 4 48 32 18 48 0 ANT DLY 0 ns
* 6 64 0 Position ________________________
* 8 90 0 MODE Hold
*10 90 1
*12 90 2 LAT N 23:18:06.080
*14 90 3 LON E 8:59:34.784
*16 90 4 HGT +2.56 m (GPS)
*attempting to track
HEALTH MONITOR ......................................................... [ OK ]
Self Test: OK Int Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS Rcv: OK
-------------- next part --------------
TIME 0:00:15.000000000 DATE 1/01/1998
LAT N 23:18:06.080
LON E 8:59:34.784 VIS SATS 10
HGT (msl) 2.56 TRACK SATS 8
HGT (gps) 2.56 RX STATUS 20
PDOP 0.0
CHN SVID MODE SS STATUS
1 2 0 255 82
2 4 0 255 82
3 6 0 255 82
4 8 0 255 82
5 10 0 255 82
6 12 0 255 82
7 14 0 255 82
8 16 0 255 82
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