Hi Sean:
Do you have any data on how many TymServe 2100 units have this problem?
Would a solution be to add a daughter board between the existing GPS and the
TymServe 2100 that would correct the year?
This might be a straight forward PIC microcontroller.
Mail_Attachment --
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html
Sean Gallagher wrote:
Good afternoon everyone,
So as most (all) of you are aware at this point what seems to be like all of the Trimble Ace III GPS receivers
have looped around their entire lifespan and are setting the date back to 1995. This is affecting many people with the
Datum/Symmetricom TymServe 2100 units. My company had two such units (we had purchased a second one when the +1 second
UTC thing happened not realizing it was a firmware v3 and 4 problem) and also a slew of Datum 635/637 PCI cards which
use the Trimble Ace III as well.
After some scrounging around on the web I found that a company in France, Heol Design
(http://www.heoldesign.com/), had created an Ace III clone. I contacted them for some information and a quote on what
sounded the most promising. These were the N014 and N024 units which were quoted to me as 85 euro for the 014 and 90
euro for the 024. I also asked them if they thought their units would correct the date problem and they reached out to
Trimble who apparently was not able (or willing?) to provide an answer. Olivier Descoubès with Heol Designs however
was willing to work with me for testing purposes and sent me 2 of the N024 units so that I could test and see if they
would work as true drop in replacements. I have attached the data sheets that I received on the units as well for your
viewing. I'm not as technical as most of you so maybe you'll see something that I don't get that you can work with.
The units came in yesterday after COB and so this morning was the moment of truth. Short answer to everything is
they don't seem to work. I hooked it in to both of my 2100's first the older Datum branded one then the newer
Symmetricom brand (although they look physically to be the exact same underlying board) really just to try and cover
all my bases. I let the first one go for about an hour and the second for only half an hour since I was already
thinking this was a bust. While it was hooked up though I telnetted in and went into the GPS menu. It gave me my
Lat/Long position and the satellites command was able to show me that I had plenty of coverage, but it was unable to
give me the time.
After that I hooked it on to one of my 635PCI cards and got one of my backup servers going. I started up the Datum
application and it did go into GPS mode which was at first promising. Typically with these cards if there is a problem
between the GPS receiver and the Datum card then it will automatically come up in Time Code mode and won't even
recognize the GPS. I let it run for about an hour while I ran to lunch and when I came back it had still not put out
time.
My guess is that these new receivers use the "Extended date" format or whatever it's called that adds more bits on
(3? - sorry I can't remember specifics) to correct the rollover and changes it from 15 years to like 157 or something
like that. And it seems like this older equipment that a lot of timing solutions use cannot handle this new output and
thus can't decode it. Again I'm just a Junior in college so this is all just theory but it's what my gut feeling is.
I've also attached pictures of these new units. They are the same size and have the 8 pin stack. There is
additionally a 10 pin stack that I had to trim down to get it to fit. Also the antenna connector is an SMB, same as
the Ace III, however it is on the other plane of the board. So if you were looking at putting it in a 635PCI card like
me I had to use tin snips and cut out a notch on the front plate of it to make it fit.
So it looks like I had to take a page from Mr. Andrew Cooper's book and have set up a rig like his using the two
2100's in unison. I have GPS going into the older one which I have reverted back to it's oldest firmware (2.84 I
think) and thus avoided the 1 second problem. This older unit is putting out a 1PPS into the newer one set mode for
1PPS that is on V3.1 of firmware with the time and date manually being set through telnet. Trying to do it at the unit
face is not feasible don't try it and I couldn't do this on the 2.84 firmware version for some reason it wouldn't
recognize the commands. A colleague of mine seems to think for some reason that I might start getting drift again with
this setup. He said that the 1PPS may not be enough to discipline the other 2100 do you guys have any thoughts on
that? It doesn't make a lot of sense to me as it's just a pulse
I had kind of a crazy thought earlier based on a project that I had considered doing. I've seen on the internet
that some people have taken a Raspberry Pi and made a timing solution out of it. At least one using what looked like
the same type of Trimble III card.
http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html
http://musingsfromthe8thfloor.com/2015/02/08/stratum-1-ntp-server-on-raspberry-pi/comment-page-1/
https://digitalnigel.com/wordpress/?p=1781
Does anyone think it would be possible to do this with these new receivers and get it to work? Even if it was only
used to discipline some larger clock unit like the 2100? Or maybe even using the older receivers but making the RPi
correct the rollover problem somehow? It looked like without me putting a lot of work into it I wouldn't be able to
get it going because of having to learn the pin programming and electrical theory etc. And I unfortunately do not have
the resources at work currently to follow this line of thinking.
**** I have just received an email from Olivier and they are aware of the TS2100 issue from a customer of theirs in
France. That customer is shipping them the unit so that Heol can investigate it in action with a 2100 and can maybe
come up with a solution.****
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