Connection setup issues

Hi Everyone,
I have 2 RS2 Rover & Base setup.
All is great in the office when I am connected to the office WIFI. But when I am in the field with no office internet nothing works. The reach will only see them in Hotspot mode (one at a time which defeats the purpose. Both RS2 have SIMS with 4G.
Can someone help with the settings as I can find no documentation on this part of the app setup.

Regards James

James, per the RS2 specs, 4G sim cards won’t work:

3.5G modem
Reach RS2 features a power-efficient 3.5G HSPA modem with 2G fallback and global coverage. Now corrections can be accessed or broadcasted over NTRIP independently, without relying on an Internet connection on your phone.

The app say it is connected with 3G which is fine. I also have Ntrip setup to the EMLID Caster.
The issue I have is the moment I leave the office my app no longer see’s the RS2’s unless I go into Each RS2 via its hotspot. I must have something setup wrong ?

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It could be I just do not understand the principle way these RS2 talk to each other and the APP.!

In order for the App to talk to the receiver, they both must be connected to the same network. So, if you let your RS2 start in hotspot mode, connect your phone/tablet to the hotspot, you will see it.

Sorry, I haven’t done anything with the Sim installed. I always use my phones hotspot and connect my base to it.

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But you can only connect to the base or rover not both at the same time?
How do you connect your base to your phones hotspot.?

I connect the base to my cell hotspot to feed NTRIP and use LoRa radio to the rover which is feeding either a 3rd party monitor or Bluetooth to my android tablet.

I do not fully understand why you have sims in both with the LoRa radio. With using my cell data, I establish my base location using NTRIP with the State CORS network. After established, internet is no longer needed. The base then transmits corrections to the rover.


I have to admit I am now so lost with this setup, I am loosing faith. I have had these 7 months with no success.!

The documentation says nothing about combining NTRIP and LoRa in the same setup.
I would not know how to setup the Base mode, Correction Input or Position Output.

1st what are you trying to use these for? What application? Simple survey or actual survey say with using PPK.

2nd have you read the documentation on how to setup a base? Are you setting it up as a single solution average/float average or Fix average. Have you configured your LoRa radio to transmit corrections?

3rd have you configured your rover to receive the corrections via LoRa radio?

4th what do you want to use as a data collector? Emlid’s App or a 3rd party data collector.

I have a CORS network available to use NTRIP to setup a base using average fix location. I have my base transmitting corrections via the LoRa radio and I have my rover setup to receive corrections via LoRa radio. I have my NMEA data output setup on Bluetooth which sends the data to my monitor or tablet which both use 3rd party software.


Ist- I have multiple appliacation. Surveying FIX positions, P4 RTK Drone control, Sensys Magnetometry Control which also requires FIX.
2nd- I have read the documentation so many times and watched every video but I find very little that works. I did have corrections running 2 days ago but that was only when I was in the office. That has also now stopped working.
3rd- I have but I dont get the corrections. I can not get the air to 9.11 on the Base as its blanked out.
4th- I use the Data for Geo referencing my surveys aerial & ground for Archaeology.

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What are you using to collect the data? A phone/tablet with Emlid’s Reachview 3?

If you are not referencing a CORS network or or some other NTRIP caster, internet isn’t needed in your setup. Try taking the sims out as I think that is confusing you.

Go outside, where you cannot connect to an already established wifi network with your RS2s and phone/tablet that has Reachview3. Let the RS2 fire up then connect to the RS2 internal hotspot (named reach:XX:XX) the password for it is emlidreach. Once connected open RV3 and setup a base per the documents here

Where the instructions say “Connect to the rover unit” you have to connect to the RS2 rover hotspot same as above just the different unit. Each unit is transmitting its own wifi (without internet) in order to configure the unit.

That should get you going.

Are you working with known points that have been surveyed in? If so you may need to dig into the post processing info on the forum.

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This seems like one of those things that would take 5 minutes to fix in person but the words just won’t come out right to sufficiently explain and I am seeing at least 3 different things that aren’t working right or the OP doesn’t understand. You have two ways of managing the receivers. They default to their internal hotspot unless told to use an external WiFi and even when they have been connected via WiFi they can revert to hotspot if that signal goes away and/or if that signal isn’t present during receiver bootup and initialization.

There are several receiver configurations that can be used to collect data via RTK.

  1. Local Base and Rover via LoRa with averaged or manually input base coordinate.
  2. Local Base input from NTRIP output to Rover. (I need to understand better why someone would do this…
  3. Rover connecting to personal (not necessarily local) base via Emlid Caster
  4. Rover on CORS via NTRIP

Which of these scenarios are you trying to use?

You have verified that both receivers are able to authenticate via NTRIP while running on just the SIM data connection?


I have been trying to connect using NTRIP using the Emlid caster.
I did manage today to get a corrections connection today but it was only on Single. So I am assuming that it was connecting to my base properly.
I did try the Lora radio method but this failed.

JP mentioned connecting the Base to the NTRIP Caster and communicating the Rover over the Lora radio. I have not heard of this before.
I have not seen any documenting on that method.

Hi JP I am trying to get the Lora Radio set up.My air rate for the Base can not be altered to 9.1 as the instructions says. it only has 18.5 available and all others are greyed out? This is not the case for the Rover though.?
In the field do you use the direct Rover hotspot to communicate with the APP to collect data.?

Where are you located, Country/State?

I am not trying to sound rude but, I am assuming you do not have much experience with GPS/RTK. These are great inexpensive units but it helps if you have some experience.

Using NTRIP to connect the base with a caster from my state CORS network just gets my base location extremely close to the actual position. When setting up a base there are three methods of averaging position:
Single - Just your RS2 or M2’s WAAS position. I have both a RS2 and a M2. Either one can be used as a base or rover
Float - Your RS2/M2’s float postition receiving corrections via NTRIP/TCP or BT, NTRIP in my case.
Fix - Same as float but in fix mode

Ohio’s CORS network’s base stations are surveyed in so getting an average fix location on my base makes it extremely close to the actual position in LAT/LON/ALT. Using average single might get you within say 3-5 feet on LAT/LON but I have seen up to 30 feet difference on ALT and this is true of any brand receiver on WAAS.

It has been a while since I setup both my RS2 and M2 using my LoRA radio. I know all settings must match. So if 18.5 is the only one available on your base, set your rover to that too. Also, if I remember correctly, you can only transmit corrections to one thing at a time. So, if you are feeding corrections to NTRIP, you cannot also feed them to LoRa. You can send NMEA to multiple things via BT or TCP.

How many messages and what rate (Hz) are you transmitting them?

Also, if someone from Emlid chimes in, I know they will want to know what version software you are running on your RS2s.

Above, you state you are trying to use Emlid’s NTRIP server. In order to do that, you would need the sim card in both receivers. The base, after establishing its position, would transmit its data to the NTRIP caster. The rover would receive corrections using NTRIP via the sim. Is there a reason you went this route instead of just a Base/Rover combination? I would have to assume large distance or difficult terrain. Try starting out basic with just a Base/Rover setup then build up to NTRIP.

The App talks to the RS2 via wifi. You must be connected to the same wifi in order to communicate with it. The App can only communicate with one receiver at a time. So in my setup, I select the RS2 first to setup my base, with the base connected to my phones hotspot. After completing setup, I select the the M2 (Rover) to setup or verify setup and if using the App for survey it is needed. With the M2 I am connected to my phones hotspot. I don’t need the internet just the same network to communicate with the M2. Like I say, I have never used a sim in mine. If I am thinking correctly, with a sim, you still connect to the Emlid wifi of the rover to do survey.


Good instructions jp-drain-sol ! You know what helped me a great deal when I got my M2’S and RS2, I read the great instructions Emlid has on their site. Pretty self explanatory on everything. I had some difficulty in a couple of things but all the great people here on the forum and Emlid support helped. In all the receivers I’ve used, I think Emlid instructions are the simplest in explaining everything. Emlid even goes into the methodology of the basics for newcomers who have no GNSS experience. I’ve tried to help people when I can, but this forum is not the place to teach people from the ground up in the GNSS world.

My advice for anyone, whether they’ve been in the GNSS world for a long time or those just getting started without any knowledge of GNSS is to READ !
I’ll help anyone I can, but if you can’t help yourself I’m not wasting my time with someone who wants me to teach them everything.


Hi JP,
thanks for the assistance. I do not have a great deal of experience (a couple of years). But I have read the Emid instructions multiple times and they do not give the detail that is required to solve issues that arise.
I am based in the UK and I am struggling to get these units to perform as they suggest they should.
Today in the field they failed again to get a status above Single. This was with LORA Radio setup of which I expected to be robust. I am using the latest version. As previously mentioned the Base unit does not allow me to set the suggest air rate. I am going to try communicating with the support team again and see if they have any Ideas for me to try. Thanks again.

Hi everyone,

Thanks for your participation in this discussion and your willingness to help!

@james.barnes1177, I’ve read through the whole thread and highlighted the main points, which introduce some uncertainties right now. I’ve left my comments so to help resolve the issues with the setup you faced.

When you’re in the office, your RS2 receivers are connected to the same local Wi-Fi network as your mobile device. When you go outdoors, Reach, and your mobile device loses the connection with this network. It means that the devices aren’t in the same network, so you can’t connect to them in ReachView 3.

You can access multiple Reach devices from ReachView 3 when those receivers and mobile devices are connected to the same network.

You have two RS2 with SIM cards that use mobile data. In such a case, you can select one of the following configurations:

  • configure both RS2 to share the separate Wi-Fi networks using the mobile data from a SIM card

For this, do the following:

  1. Go to the Mobile data tab and enable cellular network
  2. Enable Share mobile data from Reach in hotspot mode toggle bar

Reach RS2 will start to share the Internet connection via its hotspot. You can connect your mobile device to it.

However, RS2 devices will not be accessible at the same time in the app. For selecting the receivers in the app, you will need to connect to their hotspot in the Wi-Fi settings of the mobile device each time.

  • configure both RS2 to connect to the same Wi-Fi network via one of Reach’s hotspot

Here you need to enable one RS2 to share mobile data hotspot. Then, connect your mobile device and the second Reach to this network. All the devices will be connected to the same network so that you can access two RS2 in the app.

Nevertheless, please note that the Reach’s hotspot range isn’t tailored for long-range communication. If you plan to place the base and rover far away from each other, it’s better to use the configuration I’ve described below.

  • configure both RS2 to connect to the same Wi-Fi network via an external device

This will allow you to switch between them in the app at once too. Though, here you won’t need two RS2 to use the mobile data via its SIM cards at all. You can use your mobile phone’s hotspot for this when you’re working remotely.

The configuration process of connecting RS2 to the phone’s hotspot is the same as the connection to the office Wi-Fi. The only thing is that you need to choose the Connect to a hidden network before inputting the network credentials.

This point and all the other steps are described in the Connecting Reach to Internet via Wi-Fi guide. Please follow the guide’s instructions step-by-step. If you encounter any issues during the configuration, let me know at what step it appears. We’ll figure this out.

Emlid NTRIP Caster helps you to transmit the corrections between the base and rover using NTRIP protocol. It doesn’t provide corrections itself. You may think of it as an alternative method for LoRa RTK-link. For more info, I suggest checking out this blog article that explains the main differences between NTRIP Caster and Service.

When you’ve connected the base unit to the Caster, the device started to transmit its corrections to the mount point. Your rover would have received the corrections if you’d connected the rover to this mount point.

If you don’t want to keep the light of sight between the receivers, you can use this method of RTK-link establishment. LoRa radio is a low-powered radio, so it’s sensitive to any physical obstacles standing between the devices. Since you have two RS2 with the SIM cards, you can connect them to the Internet and then to the assigned mount point from the Emlid NTRIP Caster profile.

The air data rate value is grayed out when there are many RTCM3 messages selected. The more RTCM3 messages are coming, the less air data rate options are available. So, you need to uncheck some of the messages to work with less air data rate. For example, you can leave 1006 with 1074 enabled and unselect the rest of them.

Still, you can work with the available air data rate at this moment. 18.23 kb/s will shorten the maximum LoRa baseline, but it will not affect the ability to transmit and receive corrections on a small distance. As I understand, you test the connection of two devices placed close, so you should be able to receive the corrections on the rover.

Make sure you selected the same air data rate and frequency on both base and rover devices. Also, there should be no obstacles between the receivers.