> For the complete documentation index, see [llms.txt](https://docs.spadnext.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.spadnext.com/extending-and-apis/serial-connection/command-0.md).

# Device General Commands

## PING

Every 10 seconds SPAD.neXt will send a PING to the device and expects a PONG in response containing the received TICKET as payload.

{% hint style="info" %}
If no PONG is received for longer than 30 seconds, SPAD.neXt assumes the device is offline.
{% endhint %}

\
Request: `0,PING,<TICKET>;`\
Reply: `0,PONG,<TICKET>;`

## END

When SPAD.neXt exits it will send an `0,END;` command to the device, so the device knows SPAD.neXt is exiting.<br>

{% hint style="danger" %}
There is no guarantee that this command is sent, and SPAD.neXt will not wait for a reply and close the comunication immediately
{% endhint %}

Request: `0,END;`\
Reply: none


---

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