[time-nuts] Engineering commands for TymServe 2100

[Esa Heikkinen]

Bob Marshall kirjoitti:

> We have TymServe 2100 units and need the IRIG-B signal.  They are
 > disconnected from GPS and running in free mode.  I’ve set the time
 > via telnet but can only do that within about 250 milliseconds of
 > the correct time.  I see the engineering command “root engineering
> timing offset_time” but when I try it nothing happens to the time. 

It's for GPS and maybe also for external fed PPS also (not tested that). 
Some units, like mine had 10 us error in the PPS output and it was 
possible to fix this by setting that offset to zero. I have not tested 
that with PPS because there's no error.

> To correct a -200 millisec error (reported by ntpq -p) I try:
> “root engineering timing offset_time 2000000” (the units are
 >  100ns).

According to my own tests I think that command doesn't do anything 
without GPS or (maybe) external PPS.

Only way to get it in time is to feed it with external PPS first, let it 
lock to the external PPS (having all three leds on) and THEN adjust the 
time from telnet.

But without external PPS there's no point to adjust that 250 ms. error, 
because it will be there again after couple of days. It won't keep the 
time very well without any external reference unless it's rubidium based 
version.

Also, when adjusting the time from telnet you may end up always having 1 
second offset (because it may be little bit hard to press the enter just 
correct time). In that case you can use the leap second command to 
adjust the time. Just program the leap second event to nearest minute 
change and it will happen then. By doing this it's much easier to remove 
1 second error than trying to press return in the telnet just in correct 
moment. You can add or remove the leap second.

-- 
73s!
Esa
OH4KJU