[time-nuts] X72 and 1pps

Mark Sims holrum at hotmail.com
Mon Mar 5 00:33:35 EST 2018

>  I can´t find this option - I can toggle the PPS output, but not the input.
OK, I remember now...  the X72/SA22 with firmware disciplining have a bit in the control reg that reports if a PPS input has been seen.   I found some obscure reference that implied you could disable the PPS input, but that did not work, so I removed that option.

>  BTW, what´s the "set TIC" option? I can enter a number here, 
but I can´t find something about this command in the manual...

The SET TIC command issues the X72 "k" command to set the TIC offset register.   It is used to null out offsets in the value of the TIC register.  Note that this command takes 6 seconds to complete.

> What´s the expected behaviour if I go to d-e: "Enable HW discipline" ? I can´t see any changes here.

First, you need to have the PPS output enabled for disciplining to work.  Then you have to pray to the Gods of X72 Crapitude that the hardware disciplining works.  You need a good PPS input.  It can take a long time (or forever) for the X72 to decide the PPS is good enough to use.  I have had a lot of issues getting the firmware discipling to work.   

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