> 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/survey-receivers/hemisphere-s631-s321+-s321-vega.md). # Hemisphere S631 / S321+ / S321 / Vega Connect a Hemisphere S631, S321+, S321 or Vega to RTK Premium corrections over NTRIP using Carlson SurvCE or SurvPC: caster settings and the steps to a fixed solution. These steps connect a Hemisphere S631 / S321+ / S321 / Vega to the Premium Positioning correction network over NTRIP, using Carlson SurvCE / SurvPC (or PocketMax). 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-s631-s321%2B-s321-vega) to get your credentials. * Carlson SurvCE / SurvPC (or PocketMax). * 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-s631-s321%2B-s321-vega#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. Get the receiver internet-ready: You need a live internet path. Easiest: the data collector's own connection (its SIM or a phone/MiFi hotspot). The S631 also has a built-in 4G modem if you fit a SIM and set the APN. Power on and confirm it's tracking satellites. 2. Pair the receiver over Bluetooth: Pair the S631/S321 to the data collector via Bluetooth in the device OS first (it broadcasts under its serial number) so it's available to SurvCE/SurvPC. 3. Open Equip > GPS Rover: Launch Carlson SurvCE/SurvPC, open/start a job, then Equip > GPS Rover. Four tabs appear: Current, Comms, Receiver, RTK. 4. Set Manufacturer and Model (Current tab): Set Manufacturer to 'Hemisphere GNSS' and Model to 'S631' or 'S321'. List wording varies slightly by version - pick the closest Hemisphere entry. 5. Connect on the Comms tab: On Comms set Type to Bluetooth, select the paired S631/S321, and tap the green check / Connect. It reports a successful connection. 6. Choose the internet device (RTK tab): On the RTK tab set Device to 'Data Collector Internet' if the collector/phone provides the connection, or 'Internal GSM' if the SIM is in the receiver (tap the wrenches icon to set the APN). 7. Set Network to NTRIP: Set Network to 'NTRIP', then tap the wrenches icon next to Network to open the NTRIP Broadcasters screen. 8. Add the Premium Positioning caster: Tap New, name it (e.g. 'Premium Positioning'), and enter IP addr (Host) rtkpremium.xyz, Port 2101. 9. Enter YOUR NTRIP credentials: In User and Pwd type the username/password from your Premium Positioning welcome email - unique to you; never use anyone else's. 10. Download the source table: Tap the green check. SurvCE/SurvPC downloads the broadcaster's base list (source table). If nothing returns, recheck internet, host/port, and credentials. 11. Select the COMMON mountpoint: On the Bases screen open the Name dropdown and choose 'COMMON', then tap the green check. 12. Confirm and apply: Tap the green check again to return to the RTK tab. Correction type/format fields are greyed out on purpose - with NTRIP it follows what the caster advertises. Exit GPS Rover with the green check to start streaming. 13. Verify a Fixed solution: Go to Survey > Store Points and watch the status progress Autonomous → Float → FIXED (typically within a minute or two). Wait for FIXED before storing points, then check on a known mark. If you sit on Float, recheck cellular signal, the COMMON mountpoint, and your credentials. ### Steps with PocketMax 1. PocketMax alternative (if not using Carlson): If you set up corrections in Hemisphere PocketMax instead: Config > GNSS Rover > Corrections > NTRIP Client. Choose Controller Internet (or the receiver modem if SIM-equipped). Enter the same caster details - Address rtkpremium.xyz, Port 2101, Mountpoint COMMON - plus YOUR own credentials. Enable Send GGA, then Apply and wait for FIXED. PocketMax labels can vary by version - match by meaning. ### If the fix will not hold Names differ slightly between SurvCE and SurvPC versions and firmware; the layout is the same (Equip > GPS Rover, RTK tab, Network = NTRIP, wrenches icon to add the caster). Some crews drive the S631/S321 from Hemisphere's PocketMax app instead - there the path is Config > GNSS Rover > Corrections > NTRIP Client; caster host/port/mountpoint and your credentials are identical. A stable cellular signal is required; if correction age climbs above \~5 s the link is unstable. Auth errors usually mean a mistyped username/password. 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