# Autosync GPS/GNSS Output

A Transmitter with autosync installed will automatically forward (“re-tweet”) all GPS/GNSS sentences from the GNSS receiver to the main interface. Thus, it can be simultaneously used as a GPS unit on the ROV. Due to this feature, **Transmitters with autosync default to 9600 baud (Obsolete Mk II non-autosync transmitters default to 115,200 baud)**. This is to better emulate a GPS receiver. Mk III transponders are always set to 115,200 baud since they cannot have an autosync option installed. 

{% hint style="info" %}
Most users don't bother to connect the transmitter or transponder serial input and output to anything as the system will work fine with looking a the transmitter/transponder data. USing the GPS/GNSS re-tweet would be one exception to this rule.
{% endhint %}

A Receiver with autosync installed can be commanded to forward all GPS/GNSS sentences from the GNSS receiver to the main interface (see “V3” and “V0” commands). Since the receiver must be submerged in normal operation (and thus the GPS lock is lost during operation), we do not provide a method for using the ROVL RX GNSS as a substitute for a topside GPS.

The forwarded/re-tweeted GPS sentences from the ROVL units may include:

$GPGSA and/or $GNGSA - GPS dilution of position and active satellites

$GPGSV - Number of SVs in view, PRN, elevation, azimuth, and SNR

$GPVTG and/or $GNVTG - Actual track made good and speed over ground

$GPGGA and/or $GNGGA - Time, position, and fix related data

$GPGLL and/or $GNGLL - Position data: position fix, time of position fix, and status

$GPTXT - Free text, manufacturer defined

$GPRMC and/or $GNRMC - Minimum recommended Position, Velocity, and Time


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.ceruleansonar.com/c/rov-locator/autosync-option-mk-ii-only/autosync-gps-gnss-output.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
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.