[time-nuts] PRS10 not locking to 1PPS

[Miikka Raninen]

> Hello Time-Nuts,
>
> I am an user of a PRS10 Rubidium standard.
> The unit has firmware revision 3.15.
> After reset to factory settings the Time Offset (TO) was set to 1814.
> Normally it was -1814. Now de PRS10 is not locking to the 1PPS anymore.
> It will freeze when PL = 1. It will freeze after 256 seconds.
> Is there a known way to set the TO back to -1814 for the firmware revision?
> As it is a factory setting for this firmware revision.
>
> Regards,
> Erik pe1RQF (former time keeper for the Netherlands at VSL)

Ref manual for PRS10 :
https://www.thinksrs.com/downloads/pdfs/manuals/PRS10m.pdf

Check the quality of the input 1PPS. When the unit fails to lock on to
1PSS input after 256 seconds it is usually due to the 1PPS being too
unstable in phase

What do you mean by freezing? Can you check the status bytes with ST?
command? They might indicate the reason for the fault :

ST5: Frequency Lock to External 1pps
ST5 bit Condition which sets bit Corrective Action

0 PLL disabled Send PL 1 to enable
1 < 256 good 1pps inputs Provide stable 1pps inputs
2 PLL active
3 > 256 bad 1pps inputs Provide stable 1pps inputs
4 Excessive time interval Provide accurate 1pps
5 PLL restarted Provide stable 1pps inputs
6 f control saturated Wait, check 1pps inputs
7 No 1pps input Provide 1pps input

You might also want to consider updating the firmware as "(Note:
Firmware revisions prior to Rev 3.23 do not allow user TO! commands.
Check the firmware revision with the ID? command)"

- Miikka Raninen OH3GPJ