They provide feedback on the hub’s state and are logged even when no sensors are recording.
In Biosignals Studio, events appear as notifications or are stored on the device’s microSD card for later review.
Each event is categorized by severity level, with information for regular operation, a warning for minor issues, and an error for critical faults that require immediate action.
Severity Levels
| Severity Level | Description |
| 0 – Information | Normal operation or status notification Example: Connection established |
| 1 – Warning | Non-critical condition that may require user attention Example: Low battery |
| 2 – Error | Critical fault that interrupts operation or requires user intervention Example: SD card malfunction |
⚠️ While Biosignals PRO can generate all listed device events, their visibility and configuration options may vary depending on the software used (e.g., Biosignals Studio or Developer Tools). Check your software documentation for a list of supported event types.
General Device Events
System-level events reflecting overall device operation and internal state transitions.
| Events | Information | |
| 1 | Connection Established | Indicates that a Bluetooth, Wi-Fi, or USB connection has been successfully established. |
| 2 | State Change | Logged when the acquisition state changes (e.g., Standby Idle, Idle Recording). |
| 3 | Internal Error | Triggered when the system encounters an unexpected internal condition. Persistent errors should be reported to PLUX Support. |
Sensor Port Events
Reports connection changes or communication issues on individual sensor ports.
| Events | Information | |
| 1 | Sensor Connected / Disconnected | Indicates when a sensor is attached to or removed from a port, including port number information. |
| 2 | Port Change | Reports a change in port status (e.g., connected, disconnected, or power fault). |
| 3 | Overcurrent Detected | Triggered when excessive current is detected on a port. The affected port is automatically disabled for protection. |
| 4 | Communication or Configuration Error | Covers failed port communication, unsupported configurations, or invalid sensor settings. These may prevent recording or sensor detection. |
Some port events may include additional information, such as whether a newly connected sensor is powered or not.
For instance, removing and reconnecting a sensor in standby or idle mode will provide power to the sensor. However, removing and reconnecting during an active recording session will not power the sensor, and it remains turned off even when connected to the hub.
In this case, the port update event will provide additional context highlighting that the reconnected sensor is not being powered. The sensor can be turned on again after the recording session.
Recording Sessions
Defines and validates how recording sessions are started, managed, or stopped.
| Events | Information | |
| 1 | Failed Port Start / Stop | Triggered when a recording port cannot start or stop acquisition correctly. |
| 2 | Settings Validation | Confirms that all session configuration parameters are valid before recording starts. |
| 3 | Invalid Setting / Invalid Data Rate | Triggered when an invalid configuration or unsupported sampling rate is selected. |
| 4 | Invalid Session Condition | Occurs when session start, stop, pause, or resume conditions are duplicated or logically conflicting. |
| 5 | Schedule Validation | Confirms that the defined schedule and timing parameters are valid before execution. |
| 5 | Snapshot Data | Indicates that snapshot data packets are being transmitted to Biosignals Studio. |
| 6 | Snapshot End | Marks the completion of snapshot transmission. |
Memory & Storage (microSD Card)
Reports the status and health of the internal microSD card used for data logging.
Table 5: Memory & storage events
| Events | Information | |
| 1 | microSD Card Inserted / Removed | Triggered when a microSD card is inserted or removed from the device. |
| 2 | SD Card Ready | Indicates that the card has been successfully mounted and is ready for data storage. |
| 3 | SD Card Malfunction | Triggered when the SD card cannot be accessed or a read/write error occurs. |
| 4 | Acquisition Time Available | Displays the remaining recording time based on available SD card capacity. |
Power Management
Reports connection changes or communication issues on individual sensor ports.
Table 6: Power management events
| Events | Information | |
| 1 | Low Battery / Discharged Battery | Battery level dropped below a critical threshold (10% or lower). Device may shut down automatically if not charged. |
| 2 | Battery Charging / Charging Complete | Indicates that charging is active or has finished successfully. |
| 3 | Charger Connected / Disconnected | Triggered when the charger is plugged in or removed. |
| 4 | Charger Fault | Reports an error in the charging circuit (e.g., NTC, battery, or boost fault). |
| 5 | Charging-Level Low / Critical | Battery level below 10% or 5% while charging. |
Sensor Events
Both internal and external sensors can generate their own asynchronous events that are passed through Biosignals PRO. These events vary by sensor type (e.g., electrode disconnection, signal threshold crossings, or signal quality alerts), as each sensor defines its own set of events.
For details and available sensor-specific events, refer to the corresponding sensor user manuals.
Biosignals PRO includes an onboard motion sensor that computes a Motion Intensity (Motion Score) metric.
As an alternative to recording the continuous Motion Score signal, you can configure motion-related events that trigger automatically when predefined thresholds or conditions are met — for example, detecting transitions between low and high movement intensity.
| Events | Information | |
| 1 | Rising Edge Threshold | Triggered when Motion Score exceeds the upper threshold (default: 70%), marking a transition to high motion. |
| 2 | Falling Edge Threshold | Triggered when Motion Score drops below the lower threshold (default: 60%), marking a return to low motion. |
| 3 | Tolerance Margin (Hysteresis) | Adds a small gap between activation and deactivation points to prevent retriggering. Example: If motion activates above 70% and deactivates below 60%, small fluctuations between 65–70% won’t repeatedly start/stop events. |
