Using RS3 in Trimble Access


I am a surveyor in France, doing topographic surveys as well as construction survey and stakeout.

I currently have a Trimble R12i but without a radio module and I am using Trimble Access on a TSC5.

Until now I always used VRS Now and it worked fine.
I considered buying a RS3 to act as a base on site for my R12i with Emlid Caster to increase precision also for drone mapping projects.

Some of my customers are working with Trimble base stations (Zephyr 3, SPS 785, …) via radio. I can’t connect my R12i to those because I haven’t got a radio receiver in the R12i.

I thought that I could use a RS3 to connect to those bases in Lora. But my concern is about working with it in Access. I know that Emlid flow can do a lot but I would prefer using Access as I am very familiar with it and I use feature codes a lot.

Is the RS3 supported in Access to work in Lora with Trimble bases ?
How hard is to configure that and is it reliable as it is a third party receiver ?
Is anyone using a RS3 as a base with Emlid Caster for a R12 in Access ?

I don’t think Emlid Lora is compatible with Trimble 900Mhz.

Emlids solution for integrating into existing environments is the UHF option, but the base would then require the UHF transmitter, and it would need to be configured for TRIMTALK450S & RTCM3. Most current Trimble environments would also likely be running the later more compact CMR rather than RTCM so something to check with the base people.

If you are within mobile coverage NTRIP might be a better option as the base should be able to be configured to run NTRIP concurrently with the existing 900mhz.

Regarding Access you probably want to check with your Trimble dealer. There are only two niche third-party receivers (Russian) on the supported list and they are probably not going to be very interested in helping you to move to another third party receiver in their own backyard. However because there are a lot of proprietary protocols associated with supported inhouse Trimble receivers like the R12i that enable many of the features in Access (much more sophisticated than a simple NMEA steam) only they would really know.

RS3 is good, have you looked at FieldGenius Android as an alternative collector solution? It has more functionality and is very popular.

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Hi @ScanIT,

Welcome to our community!

It is possible to use Reach RS3 as a base with a Trimble R12i rover over Emlid Caster. This Trimble model meets the criteria of the Emlid Caster, so it should work fine until you have stable Internet connection.

But @Wombo is right. If you want to broadcast the correction via LoRa, you need two Reach receivers, so it won’t work with the Trimble unit.

Regarding the apps, as far as I know, you can’t use Reach RS3 with Trimble Access, but maybe it’s worth the double-check with Trimble. But overall, if you want to use the Reach RS3 as a base, you don’t need much to do in Emlid Flow. You should just set up your base by averaging its position or setting its coordinates manually. After that, you should enter the credentials of the mount point from the Emlid Caster page, and you are done. You can start surveying with the Trimble receiver using Trimble Access.

But you mentioned that you prefer to use Trimble Access. Do you miss something from Emlid Flow that would be essential for your work? Your insights would be valuable for us to determine the future steps of development.

Thank you Wombo and Zolotan,

The Trimble base is transmitting RTCM on UHF 444 MHz apparently.

I like to use Measure Codes option in Trimble Access which allows to automatically jump from one code to another when doing cross-sections :

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I see! Thank you for sharing this! Emlid Flow also supports codes and lineworks, but I see your points. A similar code selector and the curve option could be really a great help, so I’ll add them to our feature request list!

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That is good and also check the protocol in use. RS3 would need traditional TRIMTALK 450S which is common, or possibly on newer radios TrimTalk v1 which incorporates all of the traditional Trimble protocols and is supposed to backwards compatible e.g with TRIMTALK 450S.

However there are a number of other traditional protocol options that sound similar and might be configured individually but won’t work. For example, in your case they could possibly be using TT450S (HW), TRIMTALK II/IIE or TRIMMARK 3.

I think it’s likely the SPS785 has the later protocol, however I don’t know much about the device and have no experience with TrimTalk v1.

Note there are also other less common non-Trimble protocols that are supported in Trimble transmitters but won’t work with RS3. For example, if they had SATEL or PCC configured instead of the new or individual traditional Trimble protocols. However I think this would be unlikely.

I went on the jobsite today and saw that they use Trimble SPS855, TT450S @ 9600bps ; 444.9875 MHz and RTCM.

Another customer work with a SPS785 and I have to ask him which protocol he uses.