[time-nuts] Re: PRS-10 sawtooth correction with microcontroller

[James Wilson]

> On Dec 22, 2022, at 07:19, Bob Camp via time-nuts <time-nuts at lists.febo.com> wrote:
> 
> Hi
> 
> My thought was that there must be a command to set/modify the “position” of the output 
> PPS without doing anything else. Based on a quick re-read of the commands, it was the
> only candidate I saw. You kinda sorta need to have a command like that to get the output 
> lined up to the “right” on time tick time ( if that’s the sort of application you have ….). 
> 
> Bob

The PP command actually moves the pulse.

Regarding your other question about the TO command, I do not think it changes the output time pulse: it is a value that is added to the measured time-tag (PPS_IN - PPS_OUT) as the reported time-tag (what is returned by TT?). The manual describes the calibration procedure of looping the PPS_IN and PPS_OUT connections, then measuring the time-tag value of TT?. This returned value should be subtracted from the current time offset (TO?) and then set as the time offset using TO. After that, the result of the TT? command will be roughly zero. If TO actually moved the pulse, then this calibration wouldn’t work since in this looped case, it is always true that PPS_IN = PPS_OUT + cable delay.