# Configuring VOXL 2 with a new UDP port

Source: https://forum.modalai.com/topic/4158/configuring-voxl-2-with-a-new-udp-port
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2025-02-07 21:20:48 UTC by Gary Holmgren
Replies: 8 · Views: 1524

## Gary Holmgren · 2025-02-07 21:20:48 UTC

Hello, I am wokring with MAVSDK on VOXL2 and I have made a script that runs on port 14551 successfully, but if I want to make a separate script or application that also communicates via mavlink how would I configure VOXL 2 to have a new UDP  port since one port can only be used by a single instance.

Would it be as simple as modifying the vision hub config to include the following? Also what about adding a third?
```
{
    "en_localhost_mavlink_udp": true,
    "localhost_udp_port_number": 14551,
    "secondary_ip": "127.0.0.1",
    "secondary_port": 14552
}
```

such that my seperate MAVSDK script could be ran using:  ``` udpin:0.0.0.0:14552```

I guess I am a little lost from how this works in MPA. I guess a little more clarity on how new UDP ports can be opened in addition to [this documentation](https://docs.modalai.com/mavlink/#voxl-mavlink-server-configuration-file) would be helpful.

## Reply by Eric Katzfey (ModalAI staff) · 2025-02-09 20:38:51 UTC

@Gary-Holmgren Depending on what your needs are you can also connect to px4 directly through voxl-mavlink-server. It listens on port 14550 for incoming "GCS" connections and can support multiple endpoints.

## Reply by Gary Holmgren · 2025-02-09 20:48:13 UTC (in reply to Eric Katzfey)

@Eric-Katzfey Trying to run a MAVSDK example that changes some params and controls actuator outputs. So I would basically be able to let my MAVSDK scripts use 14550 just by running udpin:0.0.0.0:14550?

## Reply by Eric Katzfey (ModalAI staff) · 2025-02-11 16:54:37 UTC (in reply to Gary Holmgren)

@Gary-Holmgren Can you try it?

## Reply by Gary Holmgren · 2025-02-11 17:08:13 UTC (in reply to Eric Katzfey)

@Eric-Katzfey Yes I did run that and it output an error that stated the port was already bound to another process.

## Reply by Eric Katzfey (ModalAI staff) · 2025-02-12 17:17:47 UTC (in reply to Gary Holmgren)

@Gary-Holmgren No, what I meant was that it shouldn't matter what port MAVSDK uses, but it should try to connect to port 14550 on voxl-mavlink-server.

## Reply by Gary Holmgren · 2025-02-12 17:23:48 UTC (in reply to Eric Katzfey)

@Eric-Katzfey My apologies I guess I am confused what you mean. I tried using MAVSDK with 14550 but it wouldn't let me connect. Also, I have QGC connected using 14550 if that matters.

## Reply by Eric Katzfey (ModalAI staff) · 2025-02-12 17:26:13 UTC (in reply to Gary Holmgren)

@Gary-Holmgren Yes, only one thing can be using port 14550 on the VOXL 2. So that is voxl-mavlink-server. So, if you have another application (Something using MAVSDK) then you choose some other unused port for it and tell it to connect to port 14550. Basically voxl-mavlink-server is the server and your MAVSDK application is the client.

## Reply by Gary Holmgren · 2025-02-12 17:35:48 UTC (in reply to Eric Katzfey)

@Eric-Katzfey Ahh that makes more sense, thankyou for explaining!