Filter measurements when machinery is idle

Start with the desired capture interval and the threshold set to none. Collect enough measurements to see the operating and idle levels in the histogram before choosing a threshold.

The documented Download Filter compares each captured axis with the threshold. Measurements above the threshold are downloaded; those below it are discarded from sensor memory. Manual REC recordings are not subject to the threshold in this guide.

The original guide introduces auto thresholds from software 1.9.6 and advises against auto for a continuously running machine at fixed speed: a threshold above normal operation can prevent downloads. In that case it recommends the none threshold. Retries add capture attempts between the normal intervals and increase battery use.

The pre-1.6.3 Vibration Download filter used a short prefetch sample. The newer Download Filter described by the guide evaluates the full captured axis. Do not assume these two controls behave identically.

In the newer workflow described by this guide, each axis is a complete measurement for filtering. The sensor first sends a peak-power value calculated over that full axis capture. The histogram shows the latest 50 such values, newest first, on a logarithmic scale.

A peak-power entry can therefore exist even when the full vibration array was not downloaded. The download indication tells you which captures exceeded the threshold. Do not interpret a missing full array as evidence that no capture attempt occurred.

The filter article identifies its histogram timestamps with sensor acquisition and storage, while the separate OPC UA timestamp article describes the end of an axis download. Keep the supplied timestamp with its data source rather than assuming these two historical descriptions are interchangeable.

In the documented Peak mode, a cable-powered sensor keeps measuring during the interval and retains the capture with the highest peak power. It downloads that capture at the interval end if the threshold is exceeded. The guide does not offer Peak mode for the battery-powered sensors it describes.

In Instant mode, the sensor captures at the scheduled interval. If the threshold is not exceeded, extra attempts can follow. A successful download becomes the reference for the next normal interval; the scheduler is not necessarily aligned to fixed wall-clock boundaries.

The original example uses a 30-minute interval and 5x retries: after the scheduled attempt fails the threshold, additional capture attempts occur at 6-minute spacing until a qualifying measurement is downloaded. This is an illustration of that scheduler, not a recommended battery setting.