> For the complete documentation index, see [llms.txt](https://docs.twtg.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.twtg.io/docs/how-to/vibration-sensor-vb/communication-protocol-v2-and-v3/how-to-have-an-fft-for-threshold-values-without-periodic-messages.md).
# How to have an FFT for threshold values without periodic messages
### Introduction
The use case requests the NEON Vibration Sensor to send an FFT when either the RMS velocity or the peak acceleration is above a certain threshold of the overall values. Additionally, it is requested that the periodic FFT messages be disabled.
This requires a specific configuration in the NEON Vibration Sensor that will be explained next. This configuration can be done in the [NEON Online Configurator](https://neon-configurator.twtg.io/) and passing the downlink via LoRa or directly using SolidRed.
The explanation will be done using SolidRed, nevertheless, all the examples can be directly translated into the NEON Online Configurator.
### Enabling Triggers
To enable an FFT to be sent when an overall threshold for RMS velocity or peak acceleration is reached, first, the user must enable the FFT trigger to happen **On Event**.
Afterward, the user must define the trigger thresholds for the event messages. Select the mode to either RMS velocity or peak acceleration on the X, Y, or Z axis and the magnitude of the trigger. Please note that defining multiple triggers will produce an FFT message when any of the defined thresholds are reached. The following figure shows an example of two triggers set: the first one when the RMS velocity of the Z axis is above 100 mm/s and the second one when the peak acceleration of the Y axis is above 150 m/s².
The combination of these two settings will provide an FFT message every time the defined thresholds are reached.
### Disabling Periodic Messages
Periodic messages can be disabled by unchecking the **On Event** on the FFT trigger. Nevertheless, when it's desired that an FFT message is sent for overall threshold values of RMS velocity or peak acceleration the **On Event** FFT trigger is required. In this case, to disable the periodic FFT messages the **Calculation Interval** of the **Periodic FFT** tab must be set to **0**.
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