# CHC i93 / i90 / i76 / X7

The CHC i93, i90, i76, i73, and X7 are professional GNSS receivers by CHC Navigation (CHCNAV). The i93 and i90 are flagship models featuring built-in 4G modems, IMU tilt compensation, and multi-constellation tracking. The i76, i73, and X7 are mid-range receivers sharing the same NTRIP workflow. All receivers are configured through **LandStar 8** field software running on an Android controller or the CHC LT700/LT800 tablet.

## Requirements

* **CHC i93, i90, i76, i73, or X7** powered on with clear sky visibility
* **LandStar 8** v3.0+ on an Android controller or CHC LT700/LT800 tablet
* **Internet connection** via the receiver's internal 4G modem (SIM card — i93/i90) or the controller's cellular/Wi-Fi connection
* **RTKdata.com account** with active RTK credentials (username starting with `rtk` and password from your RTK dashboard)
* **Survey pole** with CHC adapter

{% 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 to the receiver

1. Power on your CHC receiver and wait for satellite tracking to begin (LED indicators confirm satellite lock).
2. Open **LandStar 8** on your Android controller.
3. Go to **Device** > **Connect** > **Device**.
4. Select your CHC receiver from the Bluetooth device list and tap **Connect**.
5. LandStar 8 will display the receiver model and current status once connected.
   {% endstep %}

{% step %}

#### Configure rover settings and datalink

1. In LandStar 8, go to **Device** > **Connect** > **Device** > **Rover Settings** (or navigate to the Rover configuration screen).
2. Set the **Work Mode** to **Rover**.
3. Under **Datalink**, select **NTRIP**.
4. Choose the internet source:
   * **Receiver Internal Network** — uses the receiver's built-in 4G modem (i93/i90 with SIM card inserted). Configure the APN for your carrier if prompted.
   * **Controller Network** — uses the Android controller's internet connection (phone hotspot or mobile data).

{% hint style="danger" %}
**"Receiver Internal Network" vs "Controller Network"** is the most common confusion point with CHC receivers. If your receiver does not have a SIM card or built-in modem (i76, i73, X7), you **must** select **Controller Network**. Selecting "Receiver Internal Network" on a receiver without a modem will fail silently.
{% endhint %}
{% endstep %}

{% step %}

#### Enter RTKdata.com NTRIP settings

Fill in the NTRIP connection fields. Select the tab for your region:

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

* **IP / Server Address:** `rtk.rtkdata.com`
* **IP fallback:** `13.56.117.10`
* **Port:** `2101`
* **Username / Password:** From *RTK Credentials* in the internal dashboard (not website login)
* **Mountpoint (ALL CAPS):** `AUTO`
  {% endtab %}

{% tab title="Europe" %}

* **IP / Server Address:** `eu.rtkdata.com`
* **IP fallback:** `3.73.41.96`
* **Port:** `2101`
* **Username / Password:** From *RTK Credentials* in the internal dashboard (not website login)
* **Mountpoint (ALL CAPS):** `AUTO`
  {% endtab %}

{% tab title="Australia" %}

* **IP / Server Address:** `aus.rtkdata.com`
* **IP fallback:** `54.206.56.130`
* **Port:** `2101`
* **Username / Password:** From *RTK Credentials* in the internal dashboard (not website login)
* **Mountpoint (ALL CAPS):** `AUTO`
  {% endtab %}
  {% endtabs %}

{% hint style="warning" %}
Type `AUTO` manually in all capital letters. Do not browse the mountpoint list — LandStar 8 may time out or return an incomplete list with large casters.
{% endhint %}
{% endstep %}

{% step %}

#### Verify GGA position sending

1. In the NTRIP settings, look for a **Send GGA** or **Upload GGA** option and make sure it is **enabled**.
2. GGA is **not always on by default** in LandStar 8 — you must verify this setting.

{% hint style="danger" %}
RTKdata requires GGA position data to select the nearest base station. Without GGA, the connection will succeed but no corrections will be delivered. Always verify this setting is enabled before starting your survey.
{% endhint %}
{% endstep %}

{% step %}

#### Start the RTK survey

1. Tap **Apply** or **OK** to save the rover configuration.
2. LandStar 8 will connect to the internet, then to the RTKdata NTRIP caster.
3. Watch the solution status: **Single** > **Float** > **Fixed**.
4. Once Fixed, you are ready to collect points, stake out, or run your survey workflow.
   {% endstep %}
   {% endstepper %}

## i93 / i90 tilt compensation

The i93 and i90 feature IMU-based tilt compensation. Once an RTK Fix is achieved, tilt compensation initializes after a brief walk calibration. You can then measure with the pole tilted without leveling. LandStar 8 displays the tilt angle and compensated position in real time.

## Vertical reference (heights)

{% hint style="info" %}
Heights from RTKdata.com are **ellipsoidal**, not orthometric (mean sea level). Configure a geoid model in LandStar 8 under your project coordinate system settings if your project requires orthometric heights.
{% endhint %}

## Troubleshooting

| Problem                                            | Cause                                                            | Fix                                                                                                                                                      |
| -------------------------------------------------- | ---------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------- |
| No internet connection (Receiver Internal Network) | SIM card not active, APN misconfigured, or receiver has no modem | Verify the SIM card has data and the APN is correct. If using i76/i73/X7, switch to **Controller Network** — these models may not have a built-in modem. |
| No internet connection (Controller Network)        | Controller has no data connection                                | Ensure your Android controller has mobile data or is connected to a Wi-Fi hotspot.                                                                       |
| Selected wrong network source                      | "Receiver Internal Network" on a receiver without a modem        | Switch to **Controller Network** in the Datalink settings.                                                                                               |
| Empty mountpoint list                              | Source table timeout or wrong host                               | Do not browse — type `AUTO` manually in all caps. Verify the host address is correct.                                                                    |
| No corrections received                            | GGA sending disabled                                             | Enable **Send GGA** / **Upload GGA** in the NTRIP settings. This is not always on by default in LandStar 8.                                              |
| Stuck on Float                                     | Poor sky conditions or far from base                             | Move to open sky. Check RTKdata base coverage at [rtkdata.com](https://rtkdata.com).                                                                     |
| Credentials rejected                               | Using website login instead of RTK credentials                   | Use the username (starting with `rtk`) and password from your RTK dashboard, not your website account.                                                   |
| NTRIP v2.0 features not available                  | LandStar 8 version too old                                       | Update to LandStar 8 v3.0 or later for full NTRIP v2.0 support.                                                                                          |

## Tips and tricks

* **i93 and i90 built-in 4G modems** provide the most reliable connection — insert a SIM card and select Receiver Internal Network.
* **i76, i73, and X7 users** should use Controller Network and tether the controller to a phone hotspot or use the controller's cellular data.
* **"Receiver Internal Network" vs "Controller Network"** — remember: Internal = SIM card in the receiver, Controller = internet from your Android device.
* **Update to LandStar 8 v3.0+** for NTRIP v2.0 support and improved connection stability.
* **Save the rover configuration** so your crew can reuse it across projects without reconfiguring.
* **Check correction age** in the LandStar 8 status display. Values above 5 seconds indicate an unstable internet link.
* **Keep receiver firmware updated** via CHC's firmware update tool to benefit from the latest RTK engine improvements.