Machine control, Long term testing (TOPCON)

So after the last year of updates from Emlid, I have finally been able to have a project completed, start to finish, using Emlid’s nTrip caster.

We have had our RS2 base station on the roof of our shop now for going on 3 years. Plugged into USB with a wifi access point directly beside it. Zero issues with accuracy or connectivity the entire time. In fact I haven’t even been up on the roof in over 2 years now.

While it only worked with the other RS2’s for most of that time, this year we’ve had two changes. At the start of the season, we got a DJI Mavic 3E RTK. Which has worked flawlessly with the nTrip right from the start. (it also works great with a base on site, or using CANNET).

WE also got the patches that allowed the RS2 to be more compatible with 3rd party receivers.

So. We have 3 pieces of equipment with onboard GPS.

  1. Komatsu D61 (single receiver)
  2. Komatsu D61 (dual receiver)
  3. John Deere 872GP (dual receiver)

And we also have a Topcon HyperVR base and rover, along with an F6000 data collector.

I would use the RS2 in the field, except that there is no stakeout from surface functionality, so we have to keep using the Topcon gear until that is added to Emlidstudio.

For the latest project I flew the site before we started work. Tied into the control points setout by the consultant with an RS2 and Emlid studio. Used those control point coordinates in office3D (topcon) to setup a job file for the Topcon dozers and the data collector (the Grader was not on this site).

Since I created that, along with setting up a painted mark on the sidewalk for the dozers to check into each day, I haven’t had a single issue with anything. This project has been going on roughly 1 month, and we’ve moved almost 80,000 m3 of topsoil and clay.

Our tolerance on the project is 3cm, however I let my operators know that if the dozers are out by more than 2cm, they need to call me. Most days they are under 1cm.

Our nTrip base is ~9km from the site.

I am extremely happy with this setup. For most of this season, I had a topcon base station setup on our major project, broadcasting over 450mhz to the machines. While that does mean the accuracy is as good as it can get, I had huge problems with getting radio over the entire site. a 10km long project just has too many hills to try a single base setup. I had to move it as the year went on. Which meant no gps on the far end after the move!

Even running with CANNET nTrip isn’t a great option, because the actual base they use would be about 30km from the site. So the accuracy just isn’t enough for that kind of site.

Also a single CANNET subscription is $2,800 PER MACHINE.

That means that at some times on this latest project, I’ve had 4 pieces of gear running off the Emlid nTrip. A HUGE savings.




So you are using the Emlid RS2 Base over NTRIP to provide corrections to your onsite Topcon Base to provide corrections over 450mhz radio to your equipment, correct?
Are you using Topcon receivers on the equipment?

“we’ve moved almost 80,000 m3 of topsoil and clay.”
Quite the basement! :crazy_face:
Thanks for the posting your work experience!


So all the equipment have built in Topcon receivers that can’t be removed (mast-less is so much better!)

The earlier project they were working off a Hyper VR base broadcasting on 450mhz.

This latest project every machine is connected via SIM cards to Emlids Ntrip caster directly. They get corrections from our rooftop base at the shop.

This means that if we have another site outside of range of the shop, or with poor cell service, I can use the hyper VR there as an on site base, and not have to worry about buying more Cannet subscriptions


ok, thank you for the explanation, another win for Emlid!



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Thank you for sharing your work experience! It’s really cool to see how the various pieces of equipment interact with one another and how the Emlid products round out your setup!


Will the reach three work as a base for on-site machine control. Right now I’m using TopNET live. I’m having issues with cellular connection in some of the further out areas. And not able to receive my corrections.

For onsite use, you would need to get an external radio. I was able to get it working a few years ago with a TDL-450, but I haven’t gotten an adaptor for the SRL-35 yet. (Need to find the pinout for that)

These are the choices I have on the topcon Machine control side

The only thing that would work without an adaptor would be with the nTrip caster.

If you can get a SRL-35 and an adaptor cable to the RS3, you would just use the normal Topcon UR1(UHF).

That is assuming the connection works. I used a TDL-450 before, which should be the same on the machine control end.

Would a pair of these work. Does a reach three connect to a satel radio.


To ensure the compatibility of this radio, you should double-check if it can operate in the 410.0–475.0 MHz band and transmit RTCM3 over TRIMTALK450S protocol.

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