[time-nuts] Help with Datum/Symmetricom TymServe TS2100

Greg Dowd GDowd at symmetricom.com
Tue Sep 30 20:57:27 EDT 2008

I'm surprised that this worked.  In theory, it shouldn't have.  While
you can plug it in, you should have received an error when you tried to
change the mode to GPS.  I think somebody in the manufacturing process
must have decided that it was easier just to build all GPS versions
after the merger.  Anyway, glad to hear that it worked.  You are correct
that the default Trimble config on our modules was 9600,8,O,1 with TSIP.
You may still have some problem with a phase offset.  Long, long ago,
when I originally did this code, the gps receiver was an external
Acutime with an open collector PPS.  As such, we were triggering on the
falling edge.  At some point, someone was supposed to throw an inverter
on the CM3-T, then ACE, then ACE-II, then ACE-III PPS line but I think
it got lost.  End result was that I had some bits programmed into the
seeprom at the factory to select different offset compensation as the
pulse width kept changing and I was still triggering on the falling

You can probably use the prop delay feature to correct.

And, with respect to all the noise about tech support, they do pretty
well.  They have to support 3 completely unique product lines (Datum,
Truetime & Symm) and no one does training on any of the obsolete stuff.
It is expensive to support these legacy products when the ntp server
market is really a commodity one.  And, honestly, if you had called me
at Datum (or bancomm) and asked how to modify an IRIG unit to GPS, I
would have sold you an upgrade kit (which cost $1k).  The days of
schematics in the back of the manual were over long before the merger.

Greg Dowd
gdowd at symmetricom dot com (antispam format)
Symmetricom, Inc.
"Everything should be made as simple as possible, but no simpler" Albert

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Jason Rabel
Sent: Thursday, September 25, 2008 5:59 AM
To: time-nuts at febo.com
Subject: Re: [time-nuts] Help with Datum/Symmetricom TymServe TS2100


I've successfully converted my TS2100 IRIG to a GPS model along with
other people. As far as I know, the Oncore module was never used (maybe
planned future upgrade), but the ACE-III modules work just fine.

The trick is you need to make a temporary interface with your ACE-III
set PORT1 to 9600 8O1 TSIP in, TSIP out. The receiver is probably set to
right now which is why it's not working. I dug through my old emails and
this bit of information might also be useful:

TSIPMonitor32 seemed to always (re)set the receiver to 9600-8N1. My
workaround was to use the Acutime TR_Monitor (set to the pallisade
to set the baud rate, then run TSIP chat and save the seeprom settings

You should be able to find all those programs on the Trimble FTP server.
need to mess with any jumpers or eeproms... Just be sure to flash your
firmware to the latest version (which is a couple years old at least I

As for the Rubidium upgrade, that's another can of worms. Unfortunately
nobody on the list has the LPRO model (or is admitting it), so there's
way to know exactly how the wiring hooks up or if a second power supply
needed, if the stock oscillator needs to be removed or not, also I'm
the loop and gain settings would need to be changed which one would need

Oh, incase you were wondering, the screws that hold down the GPS module
2-56 x 1/4"... Tiny little suckers...

Hope this helps,

> I have recently acquired a Datum TS2100-IRIG NTP time server.  Nice
> unit, and I do have IRIG-B to feed it, however, reading the manual I
> notice that there is a GPS version as well.  Upon taking the top of
> unit off I notice that there are the connector and standoffs for both
> and Trimble ACE-III sized receivers.  Tried plugging both in, but the

> does not seem to recognize it (always reports GPS receiver busy). 

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