> For the complete documentation index, see [llms.txt](https://docs.premium-positioning.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.premium-positioning.com/guides/oem-boards-and-integration/hemisphere-phantom-40.md). # Hemisphere Phantom 40 Connect a Hemisphere Phantom 40 or P-series OEM board to RTK Premium corrections over NTRIP through a host NTRIP client: caster settings and the steps to a fixed solution. These steps connect a Hemisphere Phantom 40 / P-series OEM to the Premium Positioning correction network over NTRIP, using Host NTRIP client / receiver commands. They assume you already have your NTRIP credentials. ### Before you start * Your NTRIP username and password, from your Premium Positioning welcome email or your account in the XYZ Platform. * No account yet? Start a [14-day free trial](https://www.premium-positioning.com/start-14-day-free-trial?utm_source=docs\&utm_medium=referral\&utm_campaign=docs\&utm_content=hemisphere-phantom-40) to get your credentials. * Host NTRIP client / receiver commands. * A working internet connection on the controller or phone. * No phone or hotspot in the field? If your controller or receiver takes a SIM, Premium Positioning [IoT SIMs](https://www.premium-positioning.com/products?utm_source=docs\&utm_medium=referral\&utm_campaign=docs\&utm_content=hemisphere-phantom-40#iot-sims) give it its own data connection. * A clear view of the sky at the point you are measuring. ### Network settings These are the same for every Premium Positioning customer. Only your username and password are unique to you. * Server or host: rtkpremium.xyz * Port: 2101 * Mountpoint: COMMON * Protocol: NTRIP ### Steps 1. Understand the architecture: Hemisphere Phantom 40 and Eclipse P-series (P326/P327) OEM boards run the Athena RTK engine and accept RTCM3 corrections on a serial port; they do not include a built-in NTRIP TCP/IP client. So your integration host connects to our NTRIP caster, pulls the RTCM3 stream, and injects those bytes into the board's correction serial port. (If your product wraps the board with a module that adds a network NTRIP client, enter the caster details directly there - the caster values are identical either way.) 2. Get your NTRIP login ready: Use the NTRIP username and password from your welcome email - unique to your account; never share or reuse someone else's. If you can't find them, contact support before continuing. 3. Point your NTRIP client at our caster: In your host NTRIP client (or the network module's NTRIP settings), enter EXACTLY: Host/Server rtkpremium.xyz, Port 2101, Mountpoint COMMON, Protocol NTRIP. Then enter YOUR OWN username and password. These four caster values are the same for every customer; only the credentials differ. 4. Connect to the board with a terminal: Connect a terminal/console to one of the board's main serial ports (A, B or C) using PocketMax, SLXMon, or any serial terminal. Note the default baud - on P-series commonly 115200 on the main ports; confirm against your data sheet. Hemisphere proprietary commands begin with `$J` and end with a carriage return and line feed (CR LF). 5. Confirm the board is tracking satellites: Turn on a position message to watch status: send `$JASC,GPGGA,1` to output GGA at 1 Hz on the current port. With the antenna outdoors and clear sky, you should see a valid position (GGA quality 1 = autonomous) within \~a minute before applying corrections. 6. Pick and configure the correction input port: Decide which port receives the RTCM3 stream. Match its baud to your host with `$JBAUD` - e.g. `$JBAUD,115200` (current port), or `$JBAUD,115200,OTHER` (opposite main port); add `,SAVE` to persist. Note: on P326/P327, Port D is a dedicated correction-input port fixed at 9600 8-N-1; for a general NTRIP/RTCM3 feed, prefer a main port (A/B/C) so you control the baud. 7. Tell the receiver to use external corrections from that port: Use `$JDIFF` to select the external-correction source: `$JDIFF,THIS` (the port you're typing into), `$JDIFF,OTHER`, or `$JDIFF,PORTA`/`PORTB`/`PORTC`. Example: corrections into Port B → `$JDIFF,PORTB`. Add `,SAVE` to persist, e.g. `$JDIFF,PORTB,SAVE`. 8. Start the RTCM3 stream from your host: Have your host NTRIP client connect to rtkpremium.xyz:2101, mountpoint COMMON, authenticate, and write the received RTCM3 bytes straight to the chosen serial port - raw pass-through, no reformatting. Match the host's serial settings (baud, 8-N-1) to the board. 9. Send your approximate position to the caster (if required): NTRIP casters typically expect a periodic NMEA GGA from the rover. Most host clients read GGA back from the receiver automatically. If your client needs a GGA feed, route the board's GGA output (from `$JASC,GPGGA,1`) to it; or use the client's manual/fixed-position option. 10. Verify corrections are arriving: Your NTRIP client should show a steady inbound data rate from the COMMON mountpoint, and the board's differential status should show corrections in use. Query the source with `$JDIFF`, and enable the RTK status message with `$JASC,PSAT,RTKSTAT,1` to see correction age and engine state. Age should stay low (a few seconds). 11. Watch the GGA quality climb to RTK: In the GGA stream the quality indicator progresses: 1 = autonomous, 2 = differential, 5 = RTK Float, 4 = RTK Fixed (standard NMEA fix-quality codes). Convergence to Fixed typically takes seconds to a couple of minutes depending on baseline and sky view. 12. Confirm RTK Fixed: You have a working setup when the GGA quality reads 4 (RTK Fixed / RTK integer fixed) with low correction age and a stable cm-level position. Persist your configuration with `$JSAVE` and wait for SAVE COMPLETE before power-cycling, so the receiver reboots already configured. ### If the fix will not hold Command names (`$JDIFF`, `$JBAUD`, `$JASC,GPGGA`, `$JASC,PSAT,RTKSTAT`, `$JSAVE`) are from the Hemisphere GNSS Technical Reference and the Eclipse P326/P327 Integrator's Guide and apply across Eclipse/Athena-based boards, but exact ports, default baud rates and available correction sources vary by board model/firmware - verify against your unit's data sheet. These OEM boards take RTCM3 on a serial port and do not include a built-in network NTRIP client, so a host application (or an integrating network module) performs the NTRIP connection and pipes RTCM3 to the receiver. For more, see [RTK corrections troubleshooting](/troubleshooting/rtk-corrections-troubleshooting.md) and [Inconsistent RTK accuracy on site](/troubleshooting/inconsistent-rtk-accuracy-on-site.md). ### Need help Support runs on business days from 09:00 CET to 17:00 ET. Contact us at or +31 85 0606 338, and include your receiver model, the mountpoint, the solution status, and the correction age. Last updated: 11 October 2026