[time-nuts] TymServe 2100 1995 Issue - A Kludgy Fix

[Esa Heikkinen]

descoubes kirjoitti:

> I am working for HEOL DESIGN company, and we are currently investigating 
> this TS2100 1995 bug. We have developped the N024, a clone of Trimble 
> ACE III receiver (which is mounted inside the TS2100). They are many 
> issues with the TS2100-ACE III internal protocol, and we have good hopes 
> to solve it out by N024 software.

Thanks for the information. Of course it would be nice to get the 
internal GPS working too.

I was planning that rude solution could be to cut off the GPS serial 
port lines and use only it's PPS output so that TS2100 sees it as 
external PPS. This would require changes to TS2100 motherboard (PPS 
should be routed so that it's feeded to Ext_PPS input). That hack would 
throw away anything else than PPS but will keep the unit in time as long 
there's no interruption on GPS reception.

Of course this means that the time, leap second data etc. must be set 
manually (like now) but the worst thing is that there would be no way to 
see any GPS status anymore.  If it loses signal, there will be 
absolutely no indication.

Another solution could be like this, but with added microcontoller. Also 
in this solution only the PPS is routed to TS2100 directly. GPS serial 
port would be routed to microcontroller instead. Microcontroller would 
handle the GPS time decoding and follow TS2100's time from IRIG-B 
signal. If it notices that TS2100 time is gone wrong, it could correct 
the time and leap second settingc etc. by using TS2100 console serial 
port. If TS2100 follows PPS correctly, this should only happen in the 
startup. This would bring back the automatic time setting but this 
requires very much work.

Also in this solution the main trouble is the loss of GPS status. To fix 
this, iw could be possible to share the TS2100 LCD display so that also 
TS2100 LCD port is routed thru the microcontroller, which could alter 
the LCD data from TS2100 before sending it to LCD. In the main display 
the 2nd line of LCD shows always "Datum Tymserve 2100", which is kind of 
useless information. So the microcontroller could filter that away and 
write the GPS status there. TS2100 LCD looks like standard "HD44780" and 
it would not impossible to capture the data, alter it and send to display.

Best regards,

-- 
73s!
Esa
OH4KJU