> For the complete documentation index, see [llms.txt](https://manuals.syride.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://manuals.syride.com/english-manual-alti-and-gps-v4/4-turning-the-instrument-on-and-off.md).
# 4) Turning the instrument on and off
#### **Turning on the instrument**
To turn on the instrument, simply press the **center button**. The screen turns on immediately and the instrument is ready to use.
Sensor initialization and GPS acquisition are performed automatically in the background.
***
**Turning off the instrument**
To turn off the instrument, use the **left and right buttons** to navigate to the **“Shutdown”** screen, then press the **center button** to confirm.
If a flight recording is in progress, a confirmation prompt will appear to prevent accidental interruption. Confirm shutdown with the center button or go back using the navigation buttons.
***
#### **Automatic shutdown**
To preserve battery life, the instrument automatically turns off after **20 minutes of inactivity**.
Inactivity is defined as the absence of:
* button presses,
* ground speed variation,
* or pressure variation.
This automatic shutdown delay can be configured using the **Syride Link** software.
***
⚠️ **Important note:** When a flight is being recorded, the instrument will not shut down automatically in order to ensure the integrity of the flight file.
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