Excessive ignition ON/OFF events on Teltonika FMB920 – How to filter or debounce signals

Jerusoa day ago

Good morning,

I am experiencing an issue with a Teltonika FMB920 device: it sends an excessive number of ignition ON/OFF notifications. I have configured the Teltonika ignition detection to a voltage range of 13.5–18 V. If the voltage is within this range, ignition is considered ON; if it falls outside, ignition is OFF.

However, the server logs show very rapid ON/OFF events, sometimes just a few seconds apart. Example:

2025-11-27 00:24:32 INFO: Event id: 353742371XXXXXX, time: 2025-11-27 00:24:24, type: ignitionOn, notifications: 1
2025-11-27 00:24:32 INFO: Event id: 353742371XXXXXX, time: 2025-11-27 00:24:26, type: ignitionOff, notifications: 0

And part of the ON/OFF event report:

27/11/2025, 00:15:11 Ignition ON
27/11/2025, 00:15:12 Ignition OFF
27/11/2025, 00:17:00 Ignition ON
27/11/2025, 00:17:06 Ignition OFF
27/11/2025, 00:17:09 Ignition ON
27/11/2025, 00:17:12 Ignition OFF

This “bouncing” causes many unnecessary events. I am looking for a solution that correctly reflects when the vehicle starts and stops, without creating multiple rapid events. Possible approaches I am considering:

Server-side filtering: Implement a minimum time threshold (e.g., only generate ignition events if the ignition state remains stable for X seconds).

Calculated attribute: Create a derived attribute for this device that smooths the ignition signal and only triggers ON/OFF when the state change is persistent.

Device configuration: Check if the FMB920 supports a built-in debounce or delay for ignition detection to prevent short voltage spikes from generating events.

I would like advice on the best method to implement this so that the events are accurate and reliable.

If Teltonika supports built-in debounce, that would be the best option because it can sample the data much more frequently.