# Basic Control / Function Keys

### IODD ST300/400, MINI PRO, MINI (Legacy)

The physical keypad on your IODD allows for quick navigation and advanced power-user shortcuts. Understanding these keys will significantly improve your workflow.

### 1. Basic Control (Press Key Once)

#### ⌨️ For Models with Keypad (ST300/400, MINI PRO, MINI, LK100)

| Key                                           | Function    | Description                                                    |
| --------------------------------------------- | ----------- | -------------------------------------------------------------- |
| ![](/files/MR6TpsEdEpCHdwqDG47Y) **\[1]**     | **Rescan**  | Rescans the root folder for new files.                         |
| ![](/files/rI7A6CyMgaOttqXfJJa4) **\[2]**     | **Up**      | Moves up in the file or item list.                             |
| ![](/files/ejknFAVleTS00OmGmJTP) **\[3]**     | **Voltage** | Displays the **VBUS minimum voltage** (Crucial for stability). |
| ![](/files/AW2YXF2zZOgUVkk7AKjH) **\[4]**     | **Back**    | Goes to the parent folder.                                     |
| ![](/files/uNTxDxwvqJOZQIWmFQmH) **\[5]**     | **Info**    | View detailed file information (size, fragmentation, etc.).    |
| ![](/files/qoECH5fRwdzrMrtobrrg) **\[6]**     | **Select**  | Selects a file to mount or enters a folder.                    |
| ![](/files/J8W3B6lF7p0bDH3AwnUh) **\[7]**     | **Eject**   | Ejects the most recently mounted virtual drive.                |
| ![](/files/5y7StYNn3ZGYzJyvAuof) **\[8]**     | **Down**    | Moves down in the file or item list.                           |
| ![](/files/buAgU1CaJyHuMYigI5Fq) **\[9]**     | **Save**    | Saves the current mount state (Auto-mounts on next boot).      |
| ![](/files/tYjaWYPUphA8i8Z9IPYT) **\[M]**     | **Menu**    | Enters or exits the system settings menu.                      |
| ![](/files/ZIhyUoLkA6faAaQq6gku) **\[0]**     | **Help**    | Accesses the built-in Help menu or active error details.       |
| ![](/files/wh8QszcaKRdk9pt9uLWi) **\[Enter]** | **Select**  | Same function as Key \[6].                                     |

### 2. Advanced Hotkeys (Long Press - 3 Seconds)

For the **ST300/400, MINI PRO, MINI (Legacy)**, holding a key for 3 seconds triggers advanced maintenance functions:

| Key      | Function            | Description                                                                     |
| -------- | ------------------- | ------------------------------------------------------------------------------- |
| **\[1]** | **Reconnect**       | Restarts the USB connection without physical removal.                           |
| **\[3]** | **WP Reconnect**    | Reconnects with **Write-Protection** enabled for all drives.                    |
| **\[4]** | **Partition List**  | Displays all partitions; allows manual selection of the default data partition. |
| **\[7]** | **Detach All**      | Reconnects with all virtual drives (ISO/VHD/IMA) unmounted.                     |
| **\[9]** | **Sleep Mode**      | Safely detaches the USB connection and enters power-saving sleep mode.          |
| **\[0]** | **Temp Disable WP** | Reconnects with Write-Protection **temporarily disabled**.                      |

### 3. Startup Keys (Hold while connecting USB)

These keys must be held **before and during** the insertion of the USB cable:

| Key                 | Mode / Function       | Description                                                                 |
| ------------------- | --------------------- | --------------------------------------------------------------------------- |
| **\[1]**            | **Factory Reset**     | Resets all settings (LCD bright, standby time, etc.) to defaults.           |
| **\[3]**            | **WP Mode**           | Starts the device in a global Write-Protected state.                        |
| **\[5]**            | **Standalone**        | Operates the IODD using external power without a PC connection.             |
| **\[7]**            | **Unmount All**       | Ensures no virtual drives are loaded upon startup.                          |
| **\[M]**            | **Standalone Menu**   | Enters the system settings menu in Standalone Mode.                         |
| **\[0]**            | **Key Info**          | Displays a list of available startup keys on the screen.                    |
| **\[9] + \[Enter]** | **Firmware Recovery** | **Force Recovery:** Hold both keys for 7s to re-flash the current firmware. |

#### 🔘 For IODD 2531 (Jog Dial)

* **Jog Up/Down**: Moves the cursor through the file list or menu items.
* **Jog Click (Center)**: Selects a file or enters a folder.
* **Back Button (Side)**: Moves to the parent folder or exits the current menu.

#### 👆 For IODD 2541 (Touch Keys)

The 2541 features a 12-button capacitive touch interface. Operation is identical to the physical keypad models, but requires a light touch rather than a press.

* **\[2] / \[8]**: Up / Down navigation.
* **\[6] / \[Enter]**: Select / Mount.
* **\[4]**: Back / Exit.

***

{% hint style="info" %}
**Correct Startup Sequence**

1. Hold the desired key firmly.
2. Plug in the USB cable.
3. Release the key once the IODD logo appears.
   {% endhint %}

***

### Terminal Verification

```bash
# Monitor kernel messages for USB reconnects/errors
$ dmesg -w | grep -i usb
```


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