> For the complete documentation index, see [llms.txt](https://docs.rtkdata.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.rtkdata.com/integration-hub/gnss-rovers-and-receivers/carlson-brx7.md).

# Carlson BRx7 RTK Setup: NTRIP in SurvPC 7

Carlson BRx7 NTRIP setup in SurvPC 7: tablet internet or SIM in the receiver, your RTKdata host, port 2101, the AUTO mountpoint and a FIXED check.

The **Carlson BRx7** is a multi-frequency GNSS receiver with a built-in 4G LTE modem, UHF radio, Bluetooth and Wi-Fi, set up from Carlson SurvPC on a Windows tablet such as the Carlson RT4 or RT5. To set up NTRIP on a Carlson BRx7 with RTKdata in SurvPC 7, open **Equip** > **3 GPS Rover**, select **Carlson** and **BRx7** on the **Current** tab, connect over **Bluetooth** on the **Comms** tab, and on the **RTK** tab set **Device:** to **Data Collector GSM or Wifi** (internet from the tablet) or **Receiver GSM** (SIM in the BRx7) and **Network:** to **NTRIP**. Tap the settings button next to **Network:**, tap **New** in **NTRIP Broadcasters** and enter the RTKdata host for your region in **IP addr:** (`rtk.rtkdata.com` for North America, `eu.rtkdata.com` for Europe or `aus.rtkdata.com` for Australia), `2101` in **Port:** and your RTK credentials in **User:** and **Pwd:**. The green check loads the bases list: select `AUTO` and confirm. SurvPC then sets **Send Rover Position to Network** itself; check that it is ticked.

In the field? Jump to the [Quick reference](#quick-reference).

Choose the server closest to your work area. All three servers share the same base station network; the difference is routing latency, see [NTRIP Server Settings](/get-started/network.md).

{% tabs %}
{% tab title="North America" %}

* **Host (domain)** in **IP addr:**: `rtk.rtkdata.com`
* **Host (IP fallback):** `13.56.117.10`, only if the hostname does not connect
* **Port:** `2101`, in **Port:**
* **Username / Password:** From *RTK Credentials* in your [account dashboard](https://rtkdata.com/my-account/rtk-credentials/), not your website login. Enter them in **User:** and **Pwd:**; the username starts with `rtk`.
* **Mountpoint (ALL CAPS):** `AUTO` (recommended), or `AUTO_WGS84`, `AUTO_ITRF2020`, `AUTO_ITRF2014`, selected from the bases list
  {% endtab %}

{% tab title="Europe" %}

* **Host (domain)** in **IP addr:**: `eu.rtkdata.com`
* **Host (IP fallback):** `3.73.41.96`, only if the hostname does not connect
* **Port:** `2101`, in **Port:**
* **Username / Password:** From *RTK Credentials* in your [account dashboard](https://rtkdata.com/my-account/rtk-credentials/), not your website login. Enter them in **User:** and **Pwd:**; the username starts with `rtk`.
* **Mountpoint (ALL CAPS):** `AUTO` (recommended), or `AUTO_WGS84`, `AUTO_ITRF2020`, `AUTO_ITRF2014`, selected from the bases list
  {% endtab %}

{% tab title="Australia" %}

* **Host (domain)** in **IP addr:**: `aus.rtkdata.com`
* **Host (IP fallback):** `54.206.56.130`, only if the hostname does not connect
* **Port:** `2101`, in **Port:**
* **Username / Password:** From *RTK Credentials* in your [account dashboard](https://rtkdata.com/my-account/rtk-credentials/), not your website login. Enter them in **User:** and **Pwd:**; the username starts with `rtk`.
* **Mountpoint (ALL CAPS):** `AUTO` (recommended), or `AUTO_WGS84`, `AUTO_ITRF2020`, `AUTO_ITRF2014`, selected from the bases list
  {% endtab %}
  {% endtabs %}

| Field                                              | Value                                                                                           |
| -------------------------------------------------- | ----------------------------------------------------------------------------------------------- |
| **Manufacturer:** and **Model:** (tab **Current**) | **Carlson** and **BRx7**                                                                        |
| **Type:** and **BT Type:** (tab **Comms**)         | **Bluetooth** and **Windows Mobile**, also on Windows 10 and 11 tablets                         |
| **Device:** (tab **RTK**)                          | **Data Collector GSM or Wifi** (internet from the tablet) or **Receiver GSM** (SIM in the BRx7) |
| **Network:** (tab **RTK**)                         | **NTRIP**                                                                                       |
| **Name:** in **NTRIP Broadcasters**                | Your own entry, for example `RTKdata`, created with **New**                                     |
| **IP addr:** and **Port:**                         | The host for your region from the tabs above, and `2101`                                        |
| **User:** and **Pwd:**                             | From *RTK Credentials*; the username starts with `rtk` and is not your website login            |
| **Name:** in **Bases for RTKdata**                 | `AUTO`, selected by its name from the loaded list                                               |
| **Send Rover Position to Network**                 | Ticked; SurvPC sets it and greys it out                                                         |
| **Message Type:**                                  | Filled in by SurvPC and greyed out                                                              |
| **Use server transformations**                     | Off                                                                                             |
| **RTK Port:**                                      | **Data**, as SurvPC sets it                                                                     |

* Enter only the hostname in **IP addr:**, without `http://` or `:2101`. SurvPC accepts a hostname there, as the Carlson guide for the BRx7 with SurvPC shows. Use the IP fallback only as described in *If the hostname does not connect* below.
* Mountpoint names are case sensitive: `AUTO` in capitals.
* One set of credentials allows one connection at a time. A second rover running at the same time needs its own data stream, see [Account & Credentials](/get-started/account-and-credentials.md#using-one-subscription-with-several-devices).

## Requirements

* **Carlson BRx7** with a clear view of the sky. For the BRx6 and BRx6+, see the FAQ below.
* **Carlson SurvPC 7** on a Windows tablet, for example a Carlson RT4 or RT5. SurvPC 7 needs Windows 10 or later, according to the Carlson release notes. This page was written for SurvPC 7.14 (release date 28 September 2026).
* **A current SurvPC 7 version.** With the tablet online, open the About window from the **File** menu, tap the grey helmet icon at the top left and run the check for software updates, as the Carlson knowledge base describes. Some steps on this page name the SurvPC 7 version they need.
* **Bluetooth** on the tablet. SurvPC controls the BRx7 over Bluetooth on both internet routes.
* **Internet for the corrections**, one of:
  * the tablet online, over Wi-Fi to a phone hotspot or mobile Wi-Fi router, or with its own SIM (**Data Collector GSM or Wifi**)
  * a **Nano-SIM** (9 x 12 mm) with a data plan in the BRx7 (**Receiver GSM**)
* **RTKdata account** with active RTK credentials (username starts with `rtk`)
* **RTKdata coverage** at your site: check the [coverage map](/get-started/coverage-map.md) before you go out

With RTKdata you need no base station of your own; the BRx7 runs as a rover.

{% hint style="info" %}
Don't have an RTKdata.com account yet? 👉 [Start 30-day Free Trial](https://rtkdata.com/try-rtk-corrections-free-for-30-days/) or [View Pricing](https://rtkdata.com/pricing/)
{% endhint %}

## Which internet route should you use: the tablet or a SIM in the BRx7?

Use **Data Collector GSM or Wifi** when the tablet running SurvPC has internet, and **Receiver GSM** when a Nano-SIM with a data plan sits in the BRx7; the NTRIP settings for RTKdata are the same on both routes. The Carlson NTRIP guide and the Carlson video for the BRx7 with SurvPC both use the tablet route.

|                                                       | **Data Collector GSM or Wifi**                                                                                                        | **Receiver GSM**                                                               |
| ----------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------ |
| Internet from                                         | The tablet: Wi-Fi to a phone hotspot or mobile Wi-Fi router, or a SIM in the tablet                                                   | The 4G LTE modem in the BRx7, with a Nano-SIM                                  |
| How corrections reach the BRx7                        | SurvPC receives them and passes them on over Bluetooth. The SurvPC dialog says: "RTK and position data will both use the Comms port." | The modem in the BRx7 makes the internet connection                            |
| Window behind the settings button next to **Device:** | **Configure Data Collector Internet**                                                                                                 | **Configure Internal GSM**, with the APN in **APN Settings**                   |
| What you need                                         | Internet on the tablet before SurvPC starts                                                                                           | Nano-SIM inserted with the BRx7 switched off, and the APN of your SIM provider |

* If **Receiver GSM** is not in the **Device:** list, use **Data Collector GSM or Wifi**.
* Some mobile carriers block port 2101. If one route does not connect, try the other one as a cross-check, see [Troubleshooting & FAQ](/support/troubleshooting-and-faq.md).

## How do you set up NTRIP on the Carlson BRx7 in SurvPC 7?

Work through the tabs of **Equip** > **3 GPS Rover** from left to right, as the SurvPC help recommends: **Current** (receiver model), **Comms** (Bluetooth), **Receiver** (antenna height) and **RTK** (internet route, NTRIP and the RTKdata entry), then select `AUTO` from the bases list and confirm with the green check.

{% stepper %}
{% step %}

### Prepare the internet connection

{% tabs %}
{% tab title="Data Collector GSM or Wifi" %}

1. Connect the tablet to the internet before you start SurvPC: Wi-Fi to a phone hotspot or mobile Wi-Fi router, or the tablet's own SIM.
2. Open a web page in the tablet's browser to check that the connection reaches the internet.
3. With a SIM in the tablet, Windows needs the APN of your SIM provider. Carlson describes this for the RT3 under Settings, Network & Internet, Cellular, Advanced Options, "Add an Internet APN".
   {% endtab %}

{% tab title="Receiver GSM" %}

1. Switch the BRx7 off. The BRx7 manual: "Ensure the unit is powered off when inserting or removing the SIM card."
2. Open battery compartment A, remove the battery and remove the cover of the card slots. The slot marked **SIM** is on the left side of the battery opening. The manual advises an ESD strap, or touching a metal object first.
3. Slide the tray backward until it clicks and lift it up, then insert the Nano-SIM with the contacts facing downward, toward the top of the unit.
4. Close the tray, refit the cover and the battery, close the battery door and switch the BRx7 on.
5. Use a SIM with a data plan. Carlson's SIM article for the BRx7, written for US carriers, asks for a monthly data-only business plan enabled for 4G, with the receiver's IMEI registered with the carrier, and states that the BRx7 is not Verizon certified. SurvPC shows the IMEI as **IMEI Code:** in the step *Choose the internet route on the RTK tab*.
   {% endtab %}
   {% endtabs %}
   {% endstep %}

{% step %}

### Select the BRx7 on the Current tab

1. Open **Equip** > **3 GPS Rover**. The tabs from left to right are **Current**, **Comms**, **Receiver** and **RTK**.
2. Set **Manufacturer:** to **Carlson** and **Model:** to **BRx7**. Since SurvPC 7.0, a wrong driver selection stops you from continuing, according to the Carlson release notes.
   {% endstep %}

{% step %}

### Connect over Bluetooth on the Comms tab

1. Set **Type:** to **Bluetooth** and **BT Type:** to **Windows Mobile**. This is the setting the SurvPC help gives ("Set the BT Type to Windows Mobile."), even though the tablet runs Windows 10 or 11.
2. Tap the wrenches button right of **BT Type:**. In **Bluetooth Devices**, tap **Find Device** and select the BRx7 by its serial number, which is its Bluetooth name. The SurvPC help recommends keeping the tablet within 10 m of the receiver while pairing.
3. Tap **Bluetooth Connect**, the Bluetooth symbol with a plug at the top right, left of the red X. **Device:** then shows the serial number, and the Bluetooth LED on the BRx7 turns blue.

Where many Bluetooth devices are around, the search can take longer or need several attempts, as the SurvPC help notes.
{% endstep %}

{% step %}

### Set the antenna height on the Receiver tab

1. Leave **Antenna Type:** on the BRx7 internal antenna that SurvPC preselects. If the BRx7 sits on a quick release adapter, select the BRx7 quick release antenna definition instead: since SurvPC 7.04.4 it is in the full antenna list, not in the default list, and SurvPC 7.08 fixed a possible wrong offset of this definition.
2. Enter **Antenna Height:** and choose **Vert** or **Slant**. On a 2 m pole measured vertically, type `2m`; SurvPC converts the value when the job uses feet. For **Slant**, measure to the bottom edge of the blue cap, which Carlson gives as 0.18 ft (54.7 mm) above the bottom of the receiver.
3. Open **Advanced** and check that **Enable SureFix** is ticked. Since SurvPC 7.01, SureFix and all satellite constellations are on by default for the BRx7.
4. Leave **aRTK** off. It uses a separate L-band subscription, not RTKdata.
   {% endstep %}

{% step %}

### Choose the internet route on the RTK tab

Open the **RTK** tab and select the route under **Device:**.

{% tabs %}
{% tab title="Data Collector GSM or Wifi" %}

1. Set **Device:** to **Data Collector GSM or Wifi**.
2. Optional check: tap the settings button (gears) next to **Device:**. The window keeps its SurvPC 6 name, **Configure Data Collector Internet**, and shows the text "RTK and position data will both use the Comms port." The SurvPC help screenshot shows **Connected** with an empty **ISP:** field when the tablet is already online.
   {% endtab %}

{% tab title="Receiver GSM" %}

1. Set **Device:** to **Receiver GSM** and tap the settings button (gears) next to it. The window keeps its SurvPC 6 name, **Configure Internal GSM**, and shows **Radio FW Version:**, **Modem IP/port:**, **IMEI Code:**, **GSM Status:** and **Provider:**.
2. Under **Provider:**, select your carrier, or **user** if it is not listed.
3. Tap the settings button (gears) right of **Provider:**. The window **APN Settings** opens with **APN Server:**, **APN User Name:** and **APN Password:**. SurvPC presets these for listed carriers, and the SurvPC help advises checking them with your carrier. With **user**, enter the APN of your SIM provider in **APN Server:** and leave the other two empty unless your provider gives you values for them.
4. Confirm with the green check. **GSM Status:** should show **SIM is online**.
5. If the status stays on **Module Initiating**, see *SIM in the BRx7* in the troubleshooting section.
   {% endtab %}
   {% endtabs %}
   {% endstep %}

{% step %}

### Select NTRIP and enter RTKdata

The NTRIP entries are the same for both routes.

1. Set **Network:** to **NTRIP**, not one of the other network options. Leave **RTK Port:** on **Data**.
2. Tap the settings button (gears) right of **Network:**. The window **NTRIP Broadcasters** opens.
3. Tap **New** and enter a name for your own entry under **Name:**, for example `RTKdata`. Do not edit a saved entry of another correction service.
4. **IP addr:** the host for your region, for example `rtk.rtkdata.com`. **Port:** `2101`.
5. **User:** and **Pwd:** from *RTK Credentials*.
6. Tap the green check. SurvPC connects to RTKdata and loads the list of bases.
   {% endstep %}

{% step %}

### Select AUTO from the bases list

1. The window **Bases for RTKdata** opens; it carries the name of your entry. Select `AUTO` under **Name:**. The list can show more entries than `AUTO`: select `AUTO`.
2. Leave **Sort Bases by Nearest** unticked and select `AUTO` by its name; with RTKdata the option does not sort the list by distance.
3. Tap the green check.

{% hint style="info" %}
**AUTO needs your position.** The `AUTO` mountpoint picks the base station from the rover position that SurvPC sends to the caster as NMEA GGA. After it loads the bases list, SurvPC sets **Send Rover Position to Network** itself and greys the box out; the SurvPC manual says that "with NTRIP, SurvPC already knows if the base wants the rover position sent". Without a position, the BRx7 logs in but receives no corrections, see [NTRIP & GGA Essentials](/integration-hub/ntrip-clients-and-field-software/ntrip-and-gga-essentials.md). Carlson documents no setting for the GGA interval. Start outside with open sky, so that the BRx7 has a position of its own.
{% endhint %}
{% endstep %}

{% step %}

### Check the RTK tab and connect

1. Back on the **RTK** tab, the base field, labelled with the name of your entry, shows `AUTO`.
2. **Message Type:** is filled in by SurvPC and greyed out.
3. **Send Rover Position to Network** is ticked and greyed out.
4. **Use server transformations** is off. Carlson describes it for networks that broadcast the transformation messages RTCM 1021 to 1027, and SurvPC 7.01 and later wait up to two minutes for them when it is ticked. With RTKdata, the `AUTO` mountpoint delivers the datum.
5. Tap the green check at the top right. SurvPC sets up the BRx7 as a rover and connects to RTKdata.
   {% endstep %}

{% step %}

### Wait for FIXED

Open **Equip** > **7 Monitor/Skyplot**, tab **Quality**, and wait outside until **Status:** shows **FIXED**, as described in *How do you know corrections are really arriving on the BRx7?* below.
{% endstep %}

{% step %}

### Save the setup as a profile

1. On the **Current** tab, tap **Save**, enter a name under **Create New Configuration:**, tick **Set as default configuration** if you want, and confirm with the green check.
2. Later, load the profile with **Load**.
3. Profiles store the NTRIP and base settings from SurvPC 7.03 on, according to the Carlson release notes. After an update from SurvPC 6 or an earlier 7.0x version, check the RTKdata entry in **NTRIP Broadcasters** and save the profile again.
   {% endstep %}
   {% endstepper %}

## How do you know corrections are really arriving on the BRx7?

RTKdata corrections are arriving on the BRx7 when **Equip** > **7 Monitor/Skyplot**, tab **Quality**, shows **Status:** **FLOAT** or **FIXED** with a low **Latency:**; **AUTONOMOUS** means that no corrections arrive, and **DGPS** means SBAS corrections, not RTKdata.

| **Status:**    | SurvPC help                                                                                                 | What it means for RTKdata                                                                                                |
| -------------- | ----------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------ |
| **AUTONOMOUS** | "No radio communication between base and rover, not precise, not accurate."                                 | No corrections arrive. Check the internet route, the RTKdata entry in **NTRIP Broadcasters**, the credentials and `AUTO` |
| **DGPS**       | "Corrections from differential sources such as WAAS or SBAS."                                               | Not proof of NTRIP. Check as for **AUTONOMOUS**                                                                          |
| **FLOAT**      | "Communication has been established, but ambiguities have not been resolved."                               | RTKdata corrections arrive. Stay under open sky, wait and check **Latency:**                                             |
| **FIXED**      | "Position has been resolved, highly precise, accurate."                                                     | Start measuring                                                                                                          |
| **SUREFIXED**  | "Position has been resolved and confirmed with a secondary GNSS solution, highly precise, highly accurate." | Start measuring                                                                                                          |

* **Latency:** shows the age of the corrections. The SurvPC help: "In most situations, a latency of 1 or 2 seconds can be expected." According to the BRx7 manual, **FLOAT** with a latency of 10 to 15 seconds most likely means L-band corrections from **aRTK**, not RTK corrections from a network.
* The **Ref** tab shows the distance to the base station.

LEDs on the BRx7, as the BRx7 manual describes them:

| LED       | State                     | Meaning                                |
| --------- | ------------------------- | -------------------------------------- |
| Satellite | Off                       | Not receiving satellites               |
| Satellite | Flashing red              | Receiving satellites but no solution   |
| Satellite | Flashing green            | Has a solution but is not fixed        |
| Satellite | Green                     | Fixed                                  |
| Satellite | Alternating red and green | GNSS receiver board abnormal           |
| Data Link | Green                     | Datalink setup complete                |
| Data Link | Flashing green            | Data transmitting normally             |
| Bluetooth | Off                       | No Bluetooth connection is established |
| Bluetooth | Blue                      | Bluetooth connection established       |

With **Receiver GSM**, a Data Link LED that stays green without flashing usually means the datalink is set up but no data is flowing. Carlson does not document whether the Data Link LED also flashes when corrections arrive over Bluetooth (**Data Collector GSM or Wifi**); on that route, use **Status:** and **Latency:** in SurvPC.

## Which coordinate system and geoid should you use with AUTO in SurvPC?

With the RTKdata `AUTO` mountpoint, set **Projection:** under **File** > **Job Settings** > **System** to a system in the regional datum that `AUTO` delivers at your position, for example NAD83(2011) in the USA or ETRS89 in Europe, and set **Geoid:** on the same page if you need orthometric heights.

* `AUTO` delivers your region's datum, chosen from your GGA position: NAD83(2011), epoch 2010.0, in the USA (NAD83(PA11) in Hawaii); NAD83(CSRS)v7, epoch 2010.0, in Canada; ETRS89 (realization ETRF2000), epoch 2010.0, in Europe; GDA2020 in Australia; and NZGD2000 in New Zealand. For regions not listed, `AUTO` falls back to WGS84(G2139) at the mid-year epoch. The datum for every region is listed in [Coordinate Systems & Datums](/get-started/coordinate-systems-and-datums.md).
* `AUTO_ITRF2020` and `AUTO_ITRF2014` deliver ITRF2020 and ITRF2014 at the current epoch, and `AUTO_WGS84` delivers WGS84(G2139) at the mid-year epoch.
* **Projection:** select a system on the datum of your mountpoint, for example a State Plane zone or UTM zone on NAD83(2011) in the USA. The SurvPC help shows **UTM/WGS 84/Automatic Zone Selection** as an example value; with `AUTO`, that does not match the datum in the USA, Canada, Europe or Australia.
* **Geoid:** tap **Edit** next to **Geoid:** and, in **Geoid Source**, choose **Select File** for a file on the tablet or **Download File**. In the USA, use GEOID18, the geoid model for NAD83(2011); Carlson continues to ship it with SurvPC 7. SurvPC 7.12 and later also install a beta of the NGS 2022 geoid, and SurvPC 7.14 shows a warning when you select it; keep GEOID18 with `AUTO`.
* Download the geoid file while you have internet. SurvPC 7.07 and later check whether the geoid file of a job is present when they switch to the job.
* After you change the geoid or the projection, SurvPC offers to recompute existing GPS points.
* Heights from RTKdata are ellipsoidal until a geoid is applied, see [Understanding Heights](/get-started/understanding-heights.md).
* If your SurvPC version shows **Convert WGS84 to NAD83** in the localization settings, leave it off with `AUTO`. The SurvPC 6 manual reserves it for North American base stations that transmit WGS84 positions: "Leave this option off for all other situations."
* To fit your survey to local control, use **Equip** > **6 Localization**.
* **aRTK** positions refer to ITRF08 at the current epoch, according to the SurvPC help, not to the datum of `AUTO`.
* A consistent offset of 50 cm to 1 m against local control usually means a datum mismatch, see [Why Your Coordinates May Be Offset](/get-started/coordinate-systems-and-datums.md#why-your-coordinates-may-be-offset).

## Which signals and RTCM messages does the BRx7 use with RTKdata?

The BRx7 receives RTKdata corrections as RTCM 3.2 with MSM4 messages (1074, 1084, 1094, 1114, 1124, 1134) and 1005, and Carlson lists "RTCM3.2 including MSM" among its RTK formats, so no format setting is needed: SurvPC fills in **Message Type:** itself.

* The BRx7 tracks GPS, GLONASS, Galileo, BeiDou and QZSS on several frequencies, including GPS L5, Galileo E5a and BeiDou B2a, according to the Carlson data sheet. RTKdata streams carry L5, E5a and B2a where the base station tracks them; some older base stations send L1 and L2 only.
* RTCM 1230 (GLONASS code-phase biases) comes from the base station, and most RTKdata base stations do not send it. Without it, a receiver from another manufacturer than the base station cannot fully resolve the GLONASS ambiguities, so GLONASS does not contribute to the RTK fix. GPS, Galileo and BeiDou are not affected.

## Troubleshooting

### No bases list, or no internet on the tablet

| Problem                                                                              | Cause                                                                                                                                                                                                                | Fix                                                                                                                                                                                                                              |
| ------------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| No bases list after the green check in **NTRIP Broadcasters**                        | Tablet offline (**Data Collector GSM or Wifi**), SIM not online (**Receiver GSM**), typo in **IP addr:**, or the port typed into the address field                                                                   | Check the internet, enter only the hostname in **IP addr:** and `2101` in **Port:**, or use the IP fallback, see *If the hostname does not connect* below                                                                        |
| **Configure Data Collector Internet** does not show **Connected**                    | The tablet has no internet                                                                                                                                                                                           | Connect the tablet to the hotspot or turn on its mobile data before you start SurvPC. With a SIM in the tablet, add the APN in Windows                                                                                           |
| Corrections can stop after **Open WebUI**, or while the BRx7 is connected over Wi-Fi | SurvPC 7.11 and later connect the tablet to the BRx7 Wi-Fi when you use **Open WebUI** in the **Help** menu, and the BRx7 Wi-Fi connection option (called **TCP/IP** since SurvPC 7.07) also uses the tablet's Wi-Fi | After using the web interface, reconnect Windows to your internet hotspot and check **Configure Data Collector Internet** for **Connected**. With **Data Collector GSM or Wifi** over Wi-Fi, connect the BRx7 over **Bluetooth** |
| Carlson RT5: corrections over Wi-Fi drop out, **FIXED** falls back                   | Windows power settings interrupt the Wi-Fi connection to the hotspot                                                                                                                                                 | Carlson recommends switching the battery setting in Windows Mobility Center from **Balanced** to **High Performance** and setting longer screen and sleep times in Power Options                                                 |

### Status stays AUTONOMOUS or DGPS

| Problem                                                            | Cause                                                                                                | Fix                                                                                                                                                                                                                                         |
| ------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Status:** stays **AUTONOMOUS** or **DGPS** after the green check | No corrections arrive: no internet on the chosen route, wrong credentials, or no mountpoint selected | Check the internet route, **User:** and **Pwd:**, then reload the bases list and select `AUTO`. **DGPS** comes from WAAS or SBAS, not from RTKdata                                                                                          |
| **Send Rover Position to Network** is not ticked                   | Bases list not reloaded, or a saved entry of another correction service in use                       | Tap the settings button (gears) right of **Network:**, confirm your RTKdata entry with the green check, select `AUTO` and check on the **RTK** tab that the box is now ticked. If it stays unticked, contact [Support](/support/support.md) |
| Test indoors or in a vehicle: login works, no corrections          | No position, so `AUTO` cannot assign a base station                                                  | Start outside under open sky and wait until the satellite LED flashes green                                                                                                                                                                 |
| SurvPC waits for or warns about transformation messages            | **Use server transformations** is ticked                                                             | Untick it. With RTKdata, `AUTO` delivers the datum                                                                                                                                                                                          |
| Login fails although the credentials look correct                  | Typo or a trailing space in **User:** or **Pwd:**                                                    | Type the username (starts with `rtk`) and password from *RTK Credentials* again by hand. If it still fails, contact [Support](/support/support.md)                                                                                          |
| Corrections stop when a second device connects                     | Two devices on one set of credentials                                                                | One data stream allows one connection. See [Account & Credentials](/get-started/account-and-credentials.md#using-one-subscription-with-several-devices)                                                                                     |

### FLOAT, but no FIXED

| Problem                                         | Cause                                                                                                         | Fix                                                                    |
| ----------------------------------------------- | ------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------- |
| **FLOAT** with **Latency:** of 10 to 15 seconds | Most likely L-band corrections from **aRTK** instead of RTKdata, according to the BRx7 manual                 | Leave **aRTK** off and check that **Latency:** drops to 1 or 2 seconds |
| **FLOAT** with a low **Latency:**               | The BRx7 receives RTK corrections; the BRx7 manual names the environment as the likely reason it does not fix | Move to a spot with a clearer view of the sky and wait                 |

### Bluetooth

| Problem                                                   | Cause                                                                                                     | Fix                                                                                                                                                                                                                               |
| --------------------------------------------------------- | --------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Find Device** does not find the BRx7                    | Tablet too far away, many Bluetooth devices around, or Bluetooth switched off in the BRx7 web interface   | Stay within 10 m and search again. If Bluetooth was switched off in the web interface, switch it on there                                                                                                                         |
| Bluetooth connection lost in the field, Bluetooth LED off | The link dropped. With **Data Collector GSM or Wifi**, the corrections reach the BRx7 only over this link | Use the Bluetooth **Reconnect** option under the helmet icon in the measurement commands. If that does not help, open **Comms**, tap the wrenches button, **Find Device**, select the serial number and tap **Bluetooth Connect** |
| Pairing fails or SurvPC connects to the wrong receiver    | **BT Type:** not on **Windows Mobile**, or several receivers in range                                     | Set **BT Type:** to **Windows Mobile** and compare the serial number with the label on the receiver                                                                                                                               |

### SIM in the BRx7

| Problem                                                                          | Cause                                                                                                                     | Fix                                                                                                                                                                                                                                                                                                                                                              |
| -------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| The window says **Configure Internal GSM** although **Receiver GSM** is selected | SurvPC 7 kept the old window names                                                                                        | Expected, not an error. The same applies to **Configure Data Collector Internet**                                                                                                                                                                                                                                                                                |
| No APN field in **Configure Internal GSM**                                       | The APN has its own window                                                                                                | Tap the settings button (gears) right of **Provider:** to open **APN Settings**                                                                                                                                                                                                                                                                                  |
| **GSM Status:** does not show **SIM is online**                                  | SIM inserted while the BRx7 was on, no suitable data plan, IMEI not registered with the carrier, or wrong **APN Server:** | Insert the Nano-SIM with the BRx7 off and check the plan and **APN Server:**. SurvPC 7.04.4 and later give a clearer error message for a missing SIM or a wrong APN server. Try **Data Collector GSM or Wifi** as a cross-check                                                                                                                                  |
| **GSM Status:** stays on **Module Initiating**                                   | The modem does not finish initializing                                                                                    | Open **Equip** > **0 GPS Utilities**, tap **Hard Reset** and confirm the warning with **OK**. Wait a minute or two until the BRx7 is back to its normal light pattern, switch it off, wait 30 seconds, switch it on and wait 1 to 2 minutes. Then confirm the **GPS Rover** settings with the green check again, as Carlson's SIM article for the BRx7 describes |
| **Receiver GSM** is not in the **Device:** list                                  | Not shown for every setup in Carlson's screenshots                                                                        | Use **Data Collector GSM or Wifi**                                                                                                                                                                                                                                                                                                                               |

### Heights or positions off

| Problem                                          | Cause                                                                                                                  | Fix                                                                                           |
| ------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------- |
| Heights are off by a constant amount             | **Vert** and **Slant** mixed up, feet and metres mixed up, or the wrong antenna definition for a quick release adapter | Check **Antenna Height:**, the measurement type and **Antenna Type:** on the **Receiver** tab |
| Heights differ by the geoid separation           | No geoid set                                                                                                           | Set **Geoid:** under **File** > **Job Settings** > **System**                                 |
| Constant horizontal offset against local control | **Projection:** not on the datum of `AUTO`                                                                             | Select a system on the datum of your mountpoint and let SurvPC recompute the points           |

### Settings lost after an update

| Problem                                                 | Cause                                                                                                          | Fix                                                                                                          |
| ------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------ |
| SIM or NTRIP settings gone after a BRx7 firmware update | Carlson's firmware guide for the BRx7 ends with **Restore Factory Settings** in the web interface              | Set up **Receiver GSM** again or load your saved profile                                                     |
| A saved profile loads but does not connect to RTKdata   | Profile from SurvPC before 7.03, which did not store NTRIP settings, or an entry of another correction service | Check the RTKdata entry in **NTRIP Broadcasters**, reload the list, select `AUTO` and save the profile again |

### If the hostname does not connect

Carlson's guides show hostnames in **IP addr:** for the tablet route. For **Receiver GSM**, Carlson shows a hostname only in the BRx7's own web interface, not in SurvPC. Keep the hostname for your region whenever it connects. Use the IP fallback only if no bases list loads although the internet and the credentials are right: enter the IP fallback for your region from the tabs at the top of this page in **IP addr:** and keep port, credentials and mountpoint.

For connection problems that are not specific to Carlson receivers, see [Common Connection Issues](/support/common-connection-issues.md).

## Frequently asked questions

### Does the Carlson BRx7 need its own SIM card for RTKdata?

No. With **Data Collector GSM or Wifi**, SurvPC receives the RTKdata corrections over the tablet's internet and passes them to the BRx7 over Bluetooth, so the receiver needs no SIM. A Nano-SIM with a data plan in the BRx7 is needed only for **Receiver GSM**, where the receiver's own 4G LTE modem makes the internet connection.

### Why is Send Rover Position to Network greyed out in SurvPC?

SurvPC sets **Send Rover Position to Network** and **Message Type:** itself when you use NTRIP and you select the mountpoint from the loaded list, and it greys both out. The SurvPC manual: "Those settings are shown in the RTK tab and are grayed out". With RTKdata the box has to be ticked, because the RTKdata `AUTO` mountpoint picks your base station from the position SurvPC sends. If it is not ticked, reload the bases list in **NTRIP Broadcasters** and select `AUTO` again.

### Can I type AUTO instead of selecting it from the bases list?

Select `AUTO` from the RTKdata bases list. Carlson's SurvPC guides choose the mountpoint in the **Bases for** window after the green check in **NTRIP Broadcasters** has loaded the list, and the SurvPC manual describes that SurvPC then knows the correction format and whether to send your position. Select `AUTO` by its name; **Sort Bases by Nearest** does not sort the RTKdata list by distance.

### Should I enter the hostname or the IP address in IP addr:?

Enter the RTKdata hostname for your region: `rtk.rtkdata.com`, `eu.rtkdata.com` or `aus.rtkdata.com`. SurvPC accepts hostnames in **IP addr:**, as the Carlson guide for the BRx7 with SurvPC shows. Use the IP fallback from the tabs at the top of this page only if the hostname does not connect.

### Which SurvPC 7 version should I use with the BRx7 and RTKdata?

Use a current SurvPC 7 release with RTKdata; this page was written for SurvPC 7.14 (28 September 2026). Several details on this page depend on changes listed in the Carlson release notes, for example SureFix on by default (7.01), NTRIP settings in profiles (7.03) and clearer modem error messages (7.04.4). How to check for updates is described under *Requirements*.

### Which BRx7 firmware should be installed?

Carlson's firmware article for the BRx7 (updated 28 July 2026) lists web interface 0.66.240409 and GNSS firmware 6.1Aa04 as current, and its change lists for GNSS 6.1Aa01 and 6.1Aa04 name RTK performance improvements. SurvPC shows the firmware of the connected receiver through the blue **i** next to **Manufacturer:** on the **Current** tab. BRx7 units with D20 or D21 serial numbers and a web interface older than 0.66.220415A need Carlson's 2022 firmware package first. The update ends with **Restore Factory Settings**, so set up the RTKdata connection again afterwards, ideally not on the morning of a job.

### Does this guide work for the Carlson BRx6 and BRx6+?

Carlson lists the BRx6+ and BRx6 as supported hardware for SurvPC 7, so select **BRx6+** or **BRx6** under **Model:** and use the same RTKdata NTRIP values. Carlson documents the NTRIP steps for these older receivers only with its older field software and the old label **Internal GSM**, and the BRx7 firmware steps do not apply to them. For the receiver SIM route, the BRx6+ needs its GSM antenna mounted instead of the UHF antenna, because it takes one of the two at a time, and Carlson's BRx6 guide connects the GSM antenna to the port **UMTS**.

### Why do older Carlson guides show Internal GSM and Data Collector Internet?

SurvPC 7.0 renamed the two internet options: **Internal GSM** became **Receiver GSM**, and **Data Collector Internet** became **Data Collector GSM or Wifi**. The settings windows behind them still carry the old names in SurvPC 7, so the window title does not mean that you picked the wrong option.

| SurvPC 6 and older Carlson guides | **Device:** in SurvPC 7        | Window title in SurvPC 7              |
| --------------------------------- | ------------------------------ | ------------------------------------- |
| **Internal GSM**                  | **Receiver GSM**               | **Configure Internal GSM**            |
| **Data Collector Internet**       | **Data Collector GSM or Wifi** | **Configure Data Collector Internet** |

## Quick reference

1. Internet: the tablet online (**Data Collector GSM or Wifi**), or a Nano-SIM with a data plan in the BRx7, inserted with the receiver off (**Receiver GSM**).
2. **Equip** > **3 GPS Rover** > **Current**: **Manufacturer:** **Carlson**, **Model:** **BRx7**.
3. **Comms**: **Type:** **Bluetooth**, **BT Type:** **Windows Mobile**, wrenches button, **Find Device**, serial number, **Bluetooth Connect**.
4. **Receiver**: **Antenna Height:** with **Vert** or **Slant**, **Advanced** > **Enable SureFix** ticked, **aRTK** off.
5. **RTK**: **Device:** **Data Collector GSM or Wifi** or **Receiver GSM** (APN in **APN Settings**, settings button (gears) right of **Provider:**), **Network:** **NTRIP**, settings button (gears) right of **Network:**.
6. **NTRIP Broadcasters**: **New**, **Name:** `RTKdata`, **IP addr:** `rtk.rtkdata.com`, `eu.rtkdata.com` or `aus.rtkdata.com` (IP fallback `13.56.117.10`, `3.73.41.96` or `54.206.56.130`), **Port:** `2101`, **User:** and **Pwd:** from *RTK Credentials*, green check.
7. **Bases for RTKdata**: select `AUTO` by its name (**Sort Bases by Nearest** unticked), green check. On **RTK**: **Send Rover Position to Network** ticked, **Use server transformations** off, green check.
8. **Equip** > **7 Monitor/Skyplot** > **Quality**: wait for **FIXED**, then save the profile under **Current** > **Save**.
9. **File** > **Job Settings** > **System**: **Projection:** on the datum of `AUTO`, **Geoid:** for orthometric heights (GEOID18 in the USA).

## Related Guides

* [NTRIP Server Settings](/get-started/network.md): the regional hosts, IP fallbacks, port and mountpoints in one reference
* [NTRIP & GGA Essentials](/integration-hub/ntrip-clients-and-field-software/ntrip-and-gga-essentials.md): why the caster needs your position before it sends corrections
* [Coordinate Systems & Datums](/get-started/coordinate-systems-and-datums.md): which datum `AUTO` and its variants deliver in each region
* [Understanding Heights](/get-started/understanding-heights.md): ellipsoidal and orthometric heights, and how to apply a geoid
* [Account & Credentials](/get-started/account-and-credentials.md): where to find your RTK credentials and how many devices can connect at once
* [Common Connection Issues](/support/common-connection-issues.md): what to check when corrections do not arrive or the fix stays on Float
* [Troubleshooting & FAQ](/support/troubleshooting-and-faq.md): port 2101, firewalls and carrier restrictions
* [Coverage Map](/get-started/coverage-map.md): check the station coverage at your site before you go out
* [GNSS Rovers & Receivers](/integration-hub/gnss-rovers-and-receivers.md): all receiver guides and the universal NTRIP parameters

## Related Industry Solutions

* [Surveying](https://rtkdata.com/surveying/)
* [Construction](https://rtkdata.com/construction/)
* [Utilities](https://rtkdata.com/utilities/)

## Which Carlson documents is this guide based on?

This guide is based on the Carlson SurvPC online help, the SurvPC user manual, Carlson knowledge base articles for the BRx7, a Carlson NTRIP configuration guide for the BRx7 with SurvPC on an RT4 tablet, the BRx7 user manual and data sheet, and the Carlson SurvPC release notes up to version 7.14 (28 September 2026). Carlson lists the BRx7 as supported hardware for SurvPC 7 and SurvPC 6.


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