Try a SYSTem:PREset first, before sending the GPS:INITial. On Sat, Oct 13, 2018 at 8:44 AM Matthew D'Asaro <[email protected]> wrote: > > All - > I have made substantial progress on my HP 58503A, but I am not > quite there yet. By watching the internal lights and the data on the > processor bus I could see that the CPU was starting to boot and then > restarting every ~15 seconds. Furthermore, the reset circuit didn't seem > to be working right. Sometimes when I power cycled it the front panel > lights would flash to indicate a self-test, other times they would not. > This seemed to indicate that the system was not being reset correctly on > start-up. More telling, when I manually triggered the reset generator > chip, the system would not ever flash its front panel lights even though > I could see that the CPU was being reset per the internal lights. > > The problem, as it turned out, was more mechanical than electrical. > As shown in the attached photo, someone had put the case back together > with a screw that was too long! It dug into the board and cut two > traces, one of which was the reset line for the UART chip (and probably > some other chips as well - I didn't fully trace the line). Once I > repaired these two traces (red wires in my picture) it booted right up > and even passed its self-test! > > However, the story does not end there. I now have it booting and > appearing to "work" but I can't get it to track satellites. I manually > set the location, date, and time with the following commands: > GPS:INIT:DATE (date) > GPS:INIT:POS (position) > GPS:INIT:TIME (time) > > I then setup the unit (inside, but with the GPS antenna near a > window) and left it turned on overnight. However, no dice. The system > does not display errors but won't track any satellites. Here is the > results of a SYSTEM:STATUS? command: > > scpi > system:status? > ------------------------------- Receiver Status > ------------------------------- > SYNCHRONIZATION ........................................... [ Outputs > Invalid ] > SmartClock Mode ___________________________ Reference Outputs > _______________ > Locked TFOM 9 FFOM 3 > Recovery 1PPS TI -- > Holdover HOLD THR 1.000 us > >> Power-up: GPS acquisition Holdover Uncertainty ____________ > Predict -- > > ACQUISITION .............................................. [ GPS 1PPS > Invalid ] > Tracking: 0 ____ Not Tracking: 14 _______ Time > ____________________________ > PRN El Az PRN El Az UTC 05:08:22 [?] 11 Oct 2018 > * 1 -- --- *10 -- --- GPS 1PPS Invalid: not > tracking > * 2 -- --- 16 35 50 ANT DLY 0 ns > * 3 -- --- *23 55 129 Position > ________________________ > * 5 -- --- 26 10 41 MODE Survey: 0% complete > * 6 -- --- 27 21 96 Suspended: track <4 sats > 7 57 267 30 25 257 INIT LAT N 47:42:01.770 > * 8 13 127 INIT LON W 122:16:26.770 > 9 81 141 INIT HGT +20.00 > m (MSL) > ELEV MASK 10 deg *attempting to track > HEALTH MONITOR ......................................................... > [ OK ] > Self Test: OK Int Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS > Rcv: OK > scpi > > > Is there anything else I can try? > > Thanks in advance, > Matthew D'Asaro > > On 10/07/2018 12:26 AM, Mark Sims wrote: > > The 58503A needs a null-modem pinout serial cable to connect to a PC. The > > baud rate defaults to 9600:8:N:1 > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.
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