AVSS Settings Reference¶

Overview¶

The AVSS (ANURA Vibration Sensing Service) settings structure defines all configurable parameters for ANURA vibration sensors. This document provides a complete reference for each setting, organized by functional category.

Settings Index¶

The following table lists all settings ordered by numeric id in the AVSS protocol with links to detailed descriptions.

AVSS Settings Structure¶
Index	Field Name	Description
0	`base_sample_rate_hz`	Base sample rate in Hz
1	`base_axis_enable`	Axis enable bitmask
2	`snippet_interval_ms`	Interval between snippets in milliseconds
3	`snippet_length`	Number of samples per snippet
4	`health_interval_ms`	Health data reporting interval in milliseconds
5	`snippet_mode`	Snippet capture mode
6	`motion_threshold_rms_g`	Motion detection threshold in g (RMS)
7	`motion_standby_delay_ms`	Delay before entering standby in milliseconds
8	`wom_sample_rate_hz`	Wake-on-motion sample rate in Hz
9	`wom_threshold_g`	Wake-on-motion threshold in g
10	`capture_mode`	Data capture mode
11	`capture_buffer_length`	Capture buffer length in samples
12	`events_motion_start_enable`	Enable motion start event detection
13	`events_motion_start_capture`	Enable capture on motion start
14	`events_motion_start_capture_duration_ms`	Motion start capture duration in milliseconds
15	`aggregates_mode`	Aggregated metrics computation mode
16	`aggregates_interval_ms`	Aggregates computation interval in milliseconds
17	`aggregates_sample_rate_hz`	Sample rate for aggregates computation in Hz
18	`aggregates_hpf_mode`	High-pass filter mode for aggregates
19	`aggregates_hpf_cutoff`	High-pass filter cutoff frequency in Hz
20	`aggregates_fft_mode`	FFT computation mode
21	`aggregates_fft_length`	FFT length in samples
22	`aggregates_param_enable_0_31`	Bitmask enabling parameters 0-31
23	`aggregates_param_enable_32_63`	Bitmask enabling parameters 32-63

Setting Categories¶

Base Sampling Configuration¶

This group controls the fundamental sampling behavior of the vibration sensor.

base_sample_rate_hz¶

Type: uint32_t Index: 0 Unit: Hz

The base sample rate for vibration measurements. This determines the number of vibration samples per second. All vibration data-consuming modules in the sensor (captures, snippets) are downstream of this processing stage, and are thus affected by this setting.

Valid Values:

512 Hz
1024 Hz
2048 Hz
4096 Hz
8192 Hz
16384 Hz

Considerations:

Higher sample rates capture higher frequency content, but increase data bandwidth usage. You may need to adjust the snippet interval and/or snippet length to avoid exceeding the available data bandwidth, which causes data loss.
The maximum frequency that is theoretically possible to capture with a samplerate of f_s is f_s / 2 (Nyquist frequency). In practice, we recommend using a sample rate that is at least three to four times the maximum frequency of interest.

base_axis_enable¶

Type: uint32_t (bitmask) Index: 1

Bitmask to enable or disable individual accelerometer axes (X, Y, Z). Disabling unused axes reduces data volume and therefore also power consumption.

Bit Mapping:

Bit 0 (least significant bit): X-axis enable
Bit 1: Y-axis enable
Bit 2: Z-axis enable

Example: 0x07 (binary: 111) enables all three axes.

snippet_interval_ms¶

Type: uint32_t Index: 2 Unit: milliseconds

Time interval between raw vibration data snippets. This controls how frequently the sensor captures and transmits raw acceleration data.

Typical Values:

60000 ms (1 minute) - Standard monitoring
300000 ms (5 minutes) - Low-frequency monitoring
10000 ms (10 seconds) - High-frequency monitoring

Considerations:

Shorter intervals increase data bandwidth usage. You may need to adjust the base sample rate and/or snippet length to avoid exceeding the available data bandwidth, which causes data loss.

snippet_length¶

Type: uint32_t Index: 3 Unit: samples

Number of samples in each raw vibration data snippet.

Choosing length in seconds:

snippet_length = base_sample_rate_hz × <duration in seconds>

Examples:

At 1024 Hz for 3 seconds: 1024 × 3 = 3072 samples
At 8192 Hz for 5 seconds: 8192 × 5 = 40960 samples

Considerations:

Longer snippets increase data bandwidth usage. You may need to adjust the base sample rate and/or snippet interval to avoid exceeding the available data bandwidth, which causes data loss.
Must fit within available memory buffer

Health Monitoring¶

health_interval_ms¶

Type: uint32_t Index: 4 Unit: milliseconds

Time interval for health monitoring data updates. Health data includes temperature, RSSI, battery voltage, and harvesting voltage.

Typical Values:

60000 ms (1 minute) - Standard monitoring
300000 ms (5 minutes) - Low-frequency monitoring
10000 ms (10 seconds) - Useful for diagnostics

Considerations:

More frequent health updates increase power consumption slightly

Snippet Mode¶

snippet_mode¶

Type: uint32_t (enumeration) Index: 5

Operating mode for snippet generation. Snippets are vibration waveforms captured with a specified interval, or continuously.

Valid Values:

0: Disabled
1: Interval
2: Continuous

Usage:

In interval mode, snippets are captured at a specified interval (cf. snippet_interval_ms).

In continuous mode, snippets are captured continuously. They can be joined into a continuous waveform, i.e. the first sample of snippet n+1 is captured 1/f_s after the last sample of snippet n.

Motion Detection & Power Management¶

This group controls the sensor’s motion detection and automatic transition to Stand-by Mode.

motion_threshold_rms_g¶

Type: float Index: 6 Unit: g (RMS)

RMS acceleration threshold above which the sensor actively measures, processes and transmits vibration data. When vibration falls below this threshold for the duration specified by motion_standby_delay_ms, the sensor enters Stand-by Mode.

Default Value: 0.05 g

Considerations:

Set based on the minimum vibration level when machine is operating
Too low: May inadvertently start due to ambient vibrations, even when the machine is stopped
Too high: May enter Stand-by while machine is still running

motion_standby_delay_ms¶

Type: uint32_t Index: 7 Unit: milliseconds

Duration of continuous no-motion condition (vibration below motion_threshold_rms_g) required before the sensor enters Stand-by Mode.

Typical Values:

5000 ms (5 seconds) - Quick response
30000 ms (30 seconds) - Standard
60000 ms (1 minute) - Conservative

Considerations:

Prevents the sensor from entering standby mode during brief periods of lower vibration amplitude
Shorter delays conserve battery as the sensor exits sampling mode faster

wom_sample_rate_hz¶

Type: uint32_t Index: 8 Unit: Hz

Valid Values:

500 Hz
200 Hz
100 Hz
50 Hz
25 Hz
13 Hz

Accelerometer sample rate used in Stand-by Mode for wake-on-motion condition evaluation.

Considerations:

Lower rates reduce power consumption in Stand-by Mode

wom_threshold_g¶

Type: float Index: 9 Unit: g

Valid Values: 0 to 1

Acceleration (at wom_sample_rate_hz) required to wake the sensor from Stand-by Mode back to Sampling Mode. Measured from the acceleration that was prevalent when the sensor entered Stand-by Mode.

Capture System¶

This group controls capture features and buffer management. The capture system produces vibration waveforms, like snippets, but are triggered by specific events or conditions instead of a time-based schedule.

capture_mode¶

Type: uint32_t (enumeration) Index: 10

Valid Values:

0: Disabled
1: Enabled

Usage: Must be enabled to use capture features.

capture_buffer_length¶

Type: uint32_t Index: 11 Unit: samples

Length of each capture report. A continuous waveform may be sent as multiple reports, for example if capture_buffer_length is shorter than events_motion_start_capture_duration_ms times base_sample_rate_hz.

Event Detection¶

This group enables detection of specific vibration events. The events can be configured to trigger functions in the sensor, such as capturing a waveform.

events_motion_start_enable¶

Type: bool Index: 12

Enable or disable detection of the motion start event. When enabled, the sensor generates an event when motion begins (transition from Stand-by to Sampling Mode).

Valid Values:

true - Enabled
false - Disabled

events_motion_start_capture¶

Type: bool Index: 13

Enable or disable vibration waveform capture when motion start event occurs. Requires events_motion_start_enable and capture_mode to be enabled.

Valid Values:

true - Enabled
false - Disabled

Usage: Useful for capturing machine behaviour during the transient run-up phase.

events_motion_start_capture_duration_ms¶

Type: uint32_t Index: 14 Unit: milliseconds

Duration of vibration waveform capture triggered by motion start event.

Considerations:

Longer durations increase data volume
May include pre-trigger data from capture buffer

Aggregated Metrics¶

This group controls the computation and transmission of aggregated vibration metrics.

aggregates_mode¶

Type: uint32_t (enumeration) Index: 15

Operating mode for aggregated metrics computation. Determines if aggregated metrics are computed and transmitted.

Valid Values:

0: Disabled
1: Enabled

aggregates_interval_ms¶

Type: uint32_t Index: 16 Unit: milliseconds

Time interval for aggregated metrics calculation and transmission.

Valid Values: Minimum 1000 (will be set to 1000 if a lower value is provided)

aggregates_sample_rate_hz¶

Type: uint32_t Index: 17 Unit: Hz

Sample rate used for aggregated metrics computation.

Valid Values:

Must be lower than or equal to base_sample_rate_hz.

512 Hz (currently only one value available)

aggregates_hpf_mode¶

Type: uint32_t (enumeration) Index: 18

Mode for high-pass filter applied to data before computing aggregated metrics.

Valid Values:

1: First-order IIR (currently only one value available)

aggregates_hpf_cutoff¶

Type: float Index: 19 Unit: Dimensionless

Decides the cutoff for the high-pass filter used in aggregates processing. Higher number => more attentuation at low frequencies.

Valid Values: From 0.01 to 0.1

aggregates_fft_mode¶

Type: uint32_t (enumeration) Index: 20

FFT (Fast Fourier Transform) computation mode for frequency domain analysis in aggregated metrics. When enabled, the sensor uses the FFT method to calculate the frequency of the highest vibration amplitude in the signal.

Valid Values:

0: Disabled
1: Enabled

aggregates_fft_length¶

Type: uint32_t Index: 21 Unit: samples

Number of samples used for FFT computation in aggregated metrics. Requires aggregates_fft_mode to be enabled.

Valid Values:

256 samples
512 samples

Frequency Resolution:

frequency resolution in Hz = aggregates_sample_rate_hz / aggregates_fft_length

aggregates_param_enable_0_31¶

Type: uint32_t (bitmask) Index: 22

Bitmask to enable individual aggregated parameters 0 through 31. Each bit enables/disables a specific computed metric.

Parameter Mapping:

Bit 0: Acceleration RMS X
Bit 1: Acceleration RMS Y
Bit 2: Acceleration RMS Z
Bit 3: Acceleration Peak X
Bit 4: Acceleration Peak Y
Bit 5: Acceleration Peak Z
Bit 6: Velocity RMS X
Bit 7: Velocity RMS Y
Bit 8: Velocity RMS Z
Bit 9: Velocity Peak X
Bit 10: Velocity Peak Y
Bit 11: Velocity Peak Z
Bit 12: Displacement Peak-to-Peak X
Bit 13: Displacement Peak-to-Peak Y
Bit 14: Displacement Peak-to-Peak Z
Bit 15: Stroke A XY
Bit 16: Stroke A YZ
Bit 17: Stroke A XZ
Bit 18: Stroke B XY
Bit 19: Stroke B YZ
Bit 20: Stroke B XZ
Bit 21: FFT Peak Frequency X
Bit 22: FFT Peak Frequency Y
Bit 23: FFT Peak Frequency Z
Bit 24: Acceleration Crest Factor X
Bit 25: Acceleration Crest Factor Y
Bit 26: Acceleration Crest Factor Z
Bits 27-31: Reserved

Usage: Enable only needed parameters to reduce computation load and transmission overhead.

aggregates_param_enable_32_63¶

Type: uint32_t (bitmask) Index: 23

Bitmask to enable individual aggregated parameters 32 through 63. Extends the parameter enable space for future metrics.

Parameter Mapping: All bits reserved for future use.