> 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/ntrip-clients-and-field-software/u-center-u-blox-f9.md). # u-center NTRIP Setup: u-blox ZED-F9P RTK Configure the u-center NTRIP client for u-blox ZED-F9P boards with RTKdata. Set COM port, baud rate, host, port 2101 and AUTO mountpoint to verify RTK fix. u-center is a free Windows desktop application from u-blox for configuring, testing, and monitoring u-blox GNSS receivers. It is the primary tool for working with u-blox ZED-F9P chips found in popular RTK boards such as the SparkFun RTK Facet, SparkFun RTK Express, ArduSimple simpleRTK2B, and standalone ZED-F9P evaluation kits. u-center includes a built-in NTRIP client that streams corrections from RTKdata.com directly to the receiver over USB, making it ideal for bench testing, firmware configuration, and verifying RTK performance. **Download:** [u-blox u-center](https://www.u-blox.com/en/product/u-center) (Windows, free) {% hint style="info" %} **u-center vs. u-center 2:** This guide covers u-center (v1), the u-blox tool for M8, M9 and F9 receivers such as the ZED-F9P. The u-blox ZED-X20P and ZED-F20P are fully supported by u-center 2 only. In u-center 2, the NTRIP client is under **Tools and Services → Services → NTRIP client**, tab **Manual**: see [u-center 2: ZED-X20P and ZED-F20P](#u-center-2-zed-x20p-and-zed-f20p). {% endhint %} ## Requirements * u-blox ZED-F9P receiver board or device (SparkFun, ArduSimple, etc.) * Multi-band GNSS antenna connected to the receiver * USB cable connecting the receiver to your Windows PC * Windows PC with u-center installed and internet access * Active RTKdata.com account with username and password {% 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 %} ## Step-by-step setup {% stepper %} {% step %} ### Connect the receiver via USB 1. Connect your u-blox F9P board to your PC via USB. 2. Launch u-center. 3. In the toolbar, click the **COM port dropdown** (top-left) and select the correct COM port. If unsure, check **Windows Device Manager → Ports (COM & LPT)** for the u-blox device. 4. Set the **baud rate** to match your receiver's configuration. Click the baud rate dropdown next to the COM port selector. * **Common baud rates:** 38400 (SparkFun default), 115200 (ArduSimple default), 9600 (u-blox factory default) 5. Click the **Connect** button (plug icon) or press **Ctrl+F9**. 6. The bottom status bar should begin showing satellite data, confirming the connection is active. {% hint style="warning" %} **Baud Rate Troubleshooting:** If the status bar shows no data or garbage characters, the baud rate is wrong. Try 38400, 115200, then 9600 until you see valid NMEA sentences in the **Text Console** (**View → Text Console**). The correct baud rate will immediately produce readable position data. {% endhint %} {% endstep %} {% step %} ### Verify satellite reception 1. Open **View → Docking Windows → Satellite Level** to see the satellite sky plot. 2. Confirm bars appear for GPS, Galileo, BeiDou, and/or GLONASS. 3. The **Fix Mode** indicator in the status bar should show at least **3D Fix** before proceeding. {% endstep %} {% step %} ### Open the NTRIP client 1. Go to **Receiver → NTRIP Client...** in the menu bar. 2. The NTRIP Client dialog will open. {% endstep %} {% step %} ### Enter RTKdata.com connection settings Fill in the NTRIP Client fields: {% tabs %} {% tab title="North America" %} * **Host (domain):** `rtk.rtkdata.com` * **Host (IP fallback):** `13.56.117.10` * **Port:** `2101` * **Username / Password:** From *RTK Credentials* in the internal dashboard (not website login) * **Mountpoint (ALL CAPS):** `AUTO` (recommended), or `AUTO_WGS84`, `AUTO_ITRF2020`, `AUTO_ITRF2014` {% endtab %} {% tab title="Europe" %} * **Host (domain):** `eu.rtkdata.com` * **Host (IP fallback):** `3.73.41.96` * **Port:** `2101` * **Username / Password:** From *RTK Credentials* in the internal dashboard (not website login) * **Mountpoint (ALL CAPS):** `AUTO` (recommended), or `AUTO_WGS84`, `AUTO_ITRF2020`, `AUTO_ITRF2014` {% endtab %} {% tab title="Australia" %} * **Host (domain):** `aus.rtkdata.com` * **Host (IP fallback):** `54.206.56.130` * **Port:** `2101` * **Username / Password:** From *RTK Credentials* in the internal dashboard (not website login) * **Mountpoint (ALL CAPS):** `AUTO` (recommended), or `AUTO_WGS84`, `AUTO_ITRF2020`, `AUTO_ITRF2014` {% endtab %} {% endtabs %} {% endstep %} {% step %} ### Start the NTRIP stream 1. Click **OK** or **Connect** to start the connection. 2. A green NTRIP icon will appear in the toolbar when the connection is active. 3. Monitor the **Fix Mode** in the bottom status bar: **3D → DGNSS → FLOAT → FIX**. 4. Convergence to RTK FIX typically takes 15 to 60 seconds with good sky conditions. **How to verify RTK is working:** * **Fix Mode** in the status bar displays **RTK FIX** (GGA fix quality = 4). * **Accuracy estimates** in the Navigation window (**View → Docking Windows → Navigation**) show horizontal accuracy of **0.01 to 0.02 m**. * The **NTRIP icon** in the toolbar stays green with no red indicators. * In the **Text Console** (**View → Text Console**), GGA messages show fix quality = 4 (RTK FIX) or 5 (Float). {% endstep %} {% endstepper %} ## Troubleshooting | Problem | Cause | Fix | | ------------------------------------------- | ---------------------------------- | --------------------------------------------------------------- | | No data after connecting COM port | Wrong baud rate | Try 38400, 115200, or 9600 | | "Connection failed" in NTRIP Client | Wrong hostname/port or no internet | Verify hostname, confirm port `2101`, check internet | | NTRIP connects but stays on FLOAT | No initial 3D fix (GGA = 0,0) | Wait for 3D fix before starting NTRIP | | Mountpoint error | Lowercase or misspelled | Enter `AUTO` in ALL CAPS | | "Timeout" errors | Firewall blocking port 2101 | Add u-center to firewall exceptions; allow outbound TCP on 2101 | | Corrections received but no RTK improvement | Antenna indoors or obstructed | Move antenna to clear 360-degree sky view | ## Tips for u-center * **u-center is a configuration and testing tool, not a field tool.** Use it to verify your F9P board works with RTKdata.com before deploying with a mobile app like SW Maps. * **Save configuration to flash.** After confirming RTK works, go to **View → Configuration View → CFG** and send "Save current configuration." This stores settings in non-volatile memory. * **Monitor RTCM data.** The **Packet Console** (**View → Packet Console**) shows raw UBX and NMEA messages, including incoming RTCM3 correction data. * **GGA output rate.** Ensure the receiver outputs GGA at 1 Hz. Check via **View → Configuration View → MSG**. * **Multi-receiver setups.** u-center supports multiple simultaneous COM port connections for testing several F9P boards at once. ## u-center 2: ZED-X20P and ZED-F20P u-center 2 is the u-blox tool for gen 10 and gen 20 receivers, including the ZED-X20P and ZED-F20P. It runs on Windows 10 and later, asks you to log in with a u-blox account at first start, and has an NTRIP client that sends your position to RTKdata and writes the corrections to the receiver over USB. The RTKdata values are the same as for u-center: the host for your region, port `2101`, the mountpoint `AUTO` and your RTK credentials. What you need for this section: * A u-blox ZED-X20P or ZED-F20P receiver with a USB port, for example the ArduSimple simpleRTK 4 Optimum or the SparkFun ZED-X20P breakout * A multi-band GNSS antenna. ArduSimple asks you to connect the antenna before you power the board. * A Windows 10 (or later) PC with [u-center 2](https://www.u-blox.com/en/u-center-2) and a u-blox account for the login at first start * Internet on the PC with outbound TCP on port `2101` * RTK credentials from *RTK Credentials* in your [account dashboard](https://rtkdata.com/my-account/rtk-credentials/) (the username starts with `rtk`) {% stepper %} {% step %} ### Connect the receiver Connect the antenna, then connect the receiver to your PC over USB (on the ArduSimple simpleRTK 4 Optimum, the USB port labelled **POWER+GPS**). In u-center 2, click **Data sources** in the left bar, then **Add data source**, select the COM port and click **Add device**. {% endstep %} {% step %} ### Wait for a position Wait for a 3D fix outdoors. u-center 2 needs the receiver's position before it starts the NTRIP connection. The ZED-X20P outputs NMEA GGA on USB by default; if you changed the configuration, enable NMEA GGA or UBX-NAV-PVT on the USB port. {% endstep %} {% step %} ### Open the NTRIP client in u-center 2 Open **Tools and Services → Services → NTRIP client** and select the **Manual** tab, where you enter the RTKdata caster. {% endstep %} {% step %} ### Enter the RTKdata settings Set **NTRIP version** to **v1.0** and **Protocol** to **HTTP**. Enter the host for your region in **Hostname (or IP address)**, `2101` in **Port**, and your RTK credentials in **Username** and **Password**. {% tabs %} {% tab title="North America" %} * **Hostname (or IP address):** `rtk.rtkdata.com` (IP fallback `13.56.117.10`, only if the hostname does not connect) * **Port:** `2101` * **Username / Password:** From *RTK Credentials* in your [account dashboard](https://rtkdata.com/my-account/rtk-credentials/), not your website login * **Mount point:** `AUTO`, selected from the list in the next step (alternatives: `AUTO_WGS84`, `AUTO_ITRF2020`, `AUTO_ITRF2014`) {% endtab %} {% tab title="Europe" %} * **Hostname (or IP address):** `eu.rtkdata.com` (IP fallback `3.73.41.96`, only if the hostname does not connect) * **Port:** `2101` * **Username / Password:** From *RTK Credentials* in your [account dashboard](https://rtkdata.com/my-account/rtk-credentials/), not your website login * **Mount point:** `AUTO`, selected from the list in the next step (alternatives: `AUTO_WGS84`, `AUTO_ITRF2020`, `AUTO_ITRF2014`) {% endtab %} {% tab title="Australia" %} * **Hostname (or IP address):** `aus.rtkdata.com` (IP fallback `54.206.56.130`, only if the hostname does not connect) * **Port:** `2101` * **Username / Password:** From *RTK Credentials* in your [account dashboard](https://rtkdata.com/my-account/rtk-credentials/), not your website login * **Mount point:** `AUTO`, selected from the list in the next step (alternatives: `AUTO_WGS84`, `AUTO_ITRF2020`, `AUTO_ITRF2014`) {% endtab %} {% endtabs %} {% endstep %} {% step %} ### Select the AUTO mount point Click **Get mount points** (some guides call this button **Save & Retrieve**). In the **Mount points** table, click the row **AUTO**. The list can show more entries: click only **AUTO** (or one of the alternatives from the previous step), then check that **Selected mount point** shows it. If `AUTO` is already selected, for example after an interruption, click **Connect**. {% endstep %} {% step %} ### Check the connection and the fix u-center 2 connects as soon as you click the row. The log shows **Authentication successful**, then **Location data sent to caster** with your position, then **Received data from Caster**. u-center 2 sends your position again every 10 seconds. In **Data view** (**Add view → Data view**), **Fix mode** moves to FLOAT and then to FIXED. {% endstep %} {% step %} ### Disconnect before you switch devices Closing the NTRIP client window does not end the connection. Click **Disconnect** before you use the same RTK credentials on another device or app. {% endstep %} {% endstepper %} {% hint style="info" %} For a test indoors without a fix, turn on **Manual position**, enter your real approximate latitude and longitude in **Latitude\[deg]** and **Longitude\[deg]**, and fill in **Altitude MSL\[m]** and **Geoid sep.\[m]** as well, for example `0` in both. With one of the four fields empty, u-center 2 does not connect. u-center 2 keeps this setting for the next start: set **Manual position** back to **Not used** before you work outdoors, and check that the position in **Location data sent to caster** is where you are. {% endhint %} ### Corrections and signals with the ZED-X20P and ZED-F20P RTKdata streams RTCM 3.2 with MSM4 messages (1074, 1084, 1094, 1114, 1124, 1134) and 1005. The ZED-X20P and ZED-F20P list 1005, 1074, 1094 and 1124 among their RTCM input messages, and the ZED-X20P-01B also lists 1084 (u-blox integration manuals and data sheets for both modules). 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. The ZED-X20P-01B needs 1230 or 1033 to fix GLONASS ambiguities and otherwise estimates them as float, so GLONASS does not contribute to the RTK fix. GPS, Galileo and BeiDou are not affected. The ZED-X20P-00B and the ZED-F20P do not track GLONASS. With `AUTO`, the receiver reports its position in your region's datum, because u-blox bases the rover position on the reference frame of the correction service. Heights are ellipsoidal, see [Understanding Heights](/get-started/understanding-heights.md) and [Coordinate Systems & Datums](/get-started/coordinate-systems-and-datums.md). ### Troubleshooting u-center 2 | Problem | Cause | Fix | | ------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Unable to start NTRIP service. Enable UBX-NAV-PVT or NMEA-Standard-GGA. | The receiver has no position yet, or neither NMEA GGA nor UBX-NAV-PVT reaches u-center 2 | Wait for a 3D fix outdoors, then enable NMEA GGA or UBX-NAV-PVT on the USB port | | Unable to retrieve mount points: \[NTRIPClientHTTPService]: Error: getaddrinfo ENOTFOUND, followed by the host | Host misspelled or pasted with a space | Type the host again, or enter the IP fallback for your region | | Unable to retrieve mount points: \[NTRIPClientHTTPService]: Connection attempt timed out. Verify validity of host and/or port number. | Wrong port, or outbound TCP on port 2101 is blocked by a firewall, VPN or mobile network | Check that Port is `2101` and that your network allows outbound TCP on port 2101 | | Authentication failed | Wrong username or password, or the website login was used | Copy username and password from RTK Credentials again. If they still fail, contact | | Unknown data received. Check the log. | The Username or Password field is empty, so u-center 2 sent no credentials | Fill in both fields and connect again | | Received data from Caster appears, but Fix mode never reaches FLOAT | A row other than AUTO or its alternatives AUTO\_WGS84, AUTO\_ITRF2020 and AUTO\_ITRF2014 was clicked | Click Disconnect, then click the row AUTO | | Connection timed out and Reconnecting... with no Received data from Caster | Manual position is on with a position far from your site | Click Disconnect, set Manual position to Not used, click Connect and check the position in Location data sent to caster | | Connection closed by Caster, and the log shows An error occurred | The network connection to RTKdata failed, for example Wi-Fi dropped or outbound TCP on port 2101 is blocked | Check the internet connection and port 2101, then click Connect | | Fix mode keeps dropping back and the log shows Reconnecting... again and again | Another device or app uses the same RTK credentials at the same time | Disconnect the other device or app. One data stream allows one connection at a time, see [Account & Credentials](/get-started/account-and-credentials.md#using-one-subscription-with-several-devices) | | The Manual tab or Get mount points is greyed out | An NTRIP connection is active, PointPerfect access was granted on the EVK or ZTP tab, or Hostname or Port is empty | Click Disconnect, click Revoke access on the EVK or ZTP tab, or fill in Hostname and Port | ## Related Guides * [NTRIP & GGA Essentials](/integration-hub/ntrip-clients-and-field-software/ntrip-and-gga-essentials.md): why the receiver needs a 3D fix before the caster will send anything back * [ArduSimple simpleRTK2B / simpleRTK3B](/integration-hub/gnss-rovers-and-receivers/ardusimple-simplertk2b.md): board-side setup for the ArduSimple F9P hardware you configure here * [SparkFun RTK Facet](/integration-hub/gnss-rovers-and-receivers/sparkfun-rtk-facet.md): board-side setup for the SparkFun ZED-F9P units and their default baud rates * [SW Maps](/integration-hub/ntrip-clients-and-field-software/sw-maps.md): the field app to move to once the bench test confirms the board reaches FIX * [GNSS Master](/integration-hub/ntrip-clients-and-field-software/gnss-master.md): switch the same F9P between Rover and Base from Android without a desktop ## Related Industry Solutions * [Robotics](https://rtkdata.com/robotics/) * [Transportation](https://rtkdata.com/transportation/) --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.rtkdata.com/integration-hub/ntrip-clients-and-field-software/u-center-u-blox-f9.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.