> For the complete documentation index, see [llms.txt](https://docs.ceruleansonar.com/c/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ceruleansonar.com/c/ethernet-rov-locator/connecting-and-powering-your-rovle-ethernet-receiver-or-transceiver/rovl-wiring/rovl-e-pc-board-internal-connections/gnss-compass-rtk-2-pin-rs-422-connection.md).

# GNSS Compass RTK (2-pin) RS-422 Connection

The GNSS Compass modules drive longer cable lengths than can be done reliably with TTL-level serial signals. The ROVL-ethernet PC board is set up to accommodate this.

The RTK (2-pin) connections use RS-422 signaling to drive the required line lengths. The Base unit transmits only and the Rover unit receives only.

{% hint style="warning" %}
Note the pinout of the Rover cable 2-pin connection is reversed from that of the Base.
{% endhint %}

<figure><img src="/files/idZuvDdbYZO0Ju6SKRP9" alt=""><figcaption></figcaption></figure>

<figure><img src="/files/xPGJ2o4dRMID7GDMl9Jk" alt=""><figcaption></figcaption></figure>