# ACO Parameters Description
ACO parameters can be edited in QGroundControl (QGC) either by connecting a USB cable to the Flight Controller or by connecting wirelessly over UDP/TCP.
Once connected through either method and after MAVLink parameters have fully loaded, navigate to **`Vehicle Configuration → Parameters`**\
Then locate **Component 191**, which corresponds to the ACO program running on the FCU/Skynode.
## **\[ACO] Collision Prevention Parameters**
### **`ACO_ALW_ACT`**
**Visible on QGC:** Yes\
**Value:** `1 = enabled`, `0 = disabled`\
Enables the collision-prevention module to always remain active, regardless of vehicle state.
### **`ACO_SFT_WID`**
**Visible on QGC:** Yes\
**Default:** `2.0` (meters)\
Safety region width used to determine the horizontal buffer around the drone.
### **`ACO_SFT_HI`**
**Visible on QGC:** Yes\
**Default:** `1.0` (meters)\
Safety region height defining the vertical protective boundary.
### **`ACO_SFT_VG`**
**Visible on QGC:** Yes\
**Default:** `5.0`\
Velocity gain applied when scaling the stopping distance during obstacle avoidance.
**Example:**\
If **ACO\_SFT\_VG = 5** and the drone is moving at **5 m/s**, the stopping threshold becomes:\
`5 × 5 = 25 meters`\
The drone will begin stopping when an obstacle is **25 meters ahead** in its direction of travel.
### **`ACO_VEL_THR`**
**Visible on QGC:** Yes\
**Default:** `0.3` (m/s)\
Minimum velocity required to classify the drone as “moving” for collision-prevention logic.
***
## **\[MAV] MAVLink Parameters**
### **`MAV_PORT`**
**Visible on QGC:** No (string parameter)\
**Value:** Serial or UDP URL.\
**Default:** `""`\
Port or URL used for MAVLink communication. If empty, the system selects a platform-specific default.
```
"MAV_PORT": "COMM_TYPE://:BAUD_RATE",
```
For example, if the MAVLink port is connected on the serial `/dev/ttyHS1` port with baud rate 921600, the entry would be:
```
"MAV_PORT": "serial:///dev/ttyHS1:921600",
```
Refer to the MAVSDK [Connecting to Systems](https://mavsdk.mavlink.io/main/en/cpp/guide/connections.html#connecting-to-systems-vehicles) documentation for more.
### **`MAV_SYS_ID`**
{% hint style="warning" %} **DEPRECATED**
{% endhint %}
**Visible on QGC:** Yes\
**Default:** `1`\
Previously used as the MAVLink system ID for the drone.
### **`MAV_COMP_ID`**
{% hint style="warning" %} **DEPRECATED**
{% endhint %}
**Visible on QGC:** Yes\
**Default:** `11`\
Previously used to identify the MAVLink component.
### **`MAV_HRBTS`**
{% hint style="warning" %} **DEPRECATED**
{% endhint %}
**Visible on QGC:** Yes\
**Value:** `1 = enabled`, `0 = disabled`\
**Default:** `1`\
Previously enabled continuous MAVLink heartbeat transmission.
### **`MAV_GCS_IP1`**
**Visible on QGC:** Yes\
**Default:** `8.8`\
First half of the Ground Control Station IP address (float). Combined with `MAV_GCS_IP2`.
### **`MAV_GCS_IP2`**
**Visible on QGC:** Yes\
**Default:** `8.8`\
Second half of the GCS IP (float). Combined with `MAV_GCS_IP1`.
**Example:**\
`8.8` + `8.8` → GCS IP becomes `8.8.8.8`
### **`MAV_GCS_PORT`**
**Visible on QGC:** Yes\
**Default:** `14550`\
UDP port used for sending MAVLink messages to the GCS.
### **`MAV_USE_UDP`**
{% hint style="warning" %} **DEPRECATED**
{% endhint %}
**Visible on QGC:** Yes\
**Value:** `1 = enabled`, `0 = disabled`\
Previously selected UDP transport instead of serial for MAVLink.
### **`MAV_OBS_MSG`**
**Visible on QGC:** Yes\
**Value:** `1 = enabled`, `0 = disabled`\
**Default:** `1`\
Controls whether `OBSTACLE_DISTANCE` messages are published.
### **`MAV_OBS_FRQ`**
**Visible on QGC:** Yes\
**Default:** `20` (Hz)\
Rate at which `OBSTACLE_DISTANCE` messages are sent. Converted internally to a period (`1000 / Hz` ms).
### **`MAV_TXT_DEL`**
**Visible on QGC:** Yes\
**Default:** `5` (seconds)\
Time delay between sending MAVLink `STATUSTEXT` messages.
### **`MAV_ACO_RST`**
**Visible on QGC:** Yes\
**Value:** `1 = restart`, `0 = no action`\
**Default:** `0`\
Triggers a restart of the collision-prevention module.
***
## **\[SF45] LiDAR Parameters**
### **`SF45_STR_THR`**
**Visible on QGC:** Yes\
**Default:** `90`\
Minimum signal strength required for a valid LiDAR return.
### **`SF45_DIS_THR`**
**Visible on QGC:** Yes\
**Default:** `5000` (mm)\
Maximum return distance considered valid (capped at 5 meters).
### **`SF45_PORT`**
**Visible on QGC:** No (string parameter)\
**Default:** `/dev/ttyACM3`\
Serial port used to communicate with the SF45 sensor.
### **`SF45_BAUD`**
**Visible on QGC:** Yes\
**Default:** `921600`\
Baud rate for the SF45 serial connection.
### **`SF45_LOW_ANG`**
**Visible on QGC:** Yes\
**Default:** `-70` degrees\
Lower bound of the scan angle. Automatically forced negative.
### **`SF45_HI_ANG`**
**Visible on QGC:** Yes\
**Default:** `70` degrees\
Upper bound of the scan angle. Automatically forced positive.
***
## **\[FXG] Foxglove Visualization Parameters**
### **`FXG_NAME`**
**Visible on QGC:** No (string parameter)\
**Default:** `"Ascend Collision Overwatch"`\
Name used for the Foxglove WebSocket server.
### **`FXG_HOST`**
**Visible on QGC:** No (string parameter)\
**Default:** `"0.0.0.0"`\
Host address on which the server listens.
### **`FXG_PORT`**
**Visible on QGC:** Yes\
**Default:** `8765`\
Port used by the Foxglove server.
### **`FXG_VIS`**
**Visible on QGC:** Yes\
**Value:** `1 = enabled`, `0 = disabled`\
**Default:** `1`\
Turns the visualization interface on or off.
### **`FXG_SV_LOG`**
**Visible on QGC:** Yes\
**Value:** `1 = enable logging`, `0 = disable logging`\
**Default:** `0`\
Enables saving data to MCAP log files.
### **`FXG_SV_LOG_PATH`**
**Visible on QGC:** No (string parameter)\
**Default:** `/home/root/mcap_recordings/`\
Directory where MCAP logs are stored when logging is enabled.
***
---
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