Driver Fatigue Alerts

Digital Matter devices have the capability to buzz and/or set a digital output after a period of time in trip. 

DeviceFirmware Version
G1001.23
G1202.6 (timeouts extended in 2.15)
Dart22.3/3.3

How does this feature work?

  • When a trip starts, the warning and alert countdowns begin. 
  • These countdowns will continue until they elapse or the trip ends. 
  • When the warning countdown elapses, the warning buzzer will sound, and when the alert countdown elapses the alert buzzer will sound and any enabled digital outputs will be set.

Typically this is used for driver fatigue. The warning buzzer is used to alert the driver that they are nearing their maximum allowable driving time, and the alert buzzer is used to alert the driver that they have reached the maximum allowable time and must take a break as soon as possible. The output also aids in telling the driver that they must take a break soon, for example, it could be wired to a light as a reminder that they are required to take a break.

Resetting the timer/countdown:

Since the countdown is based on trips, if the device is wired for ignition based trips, the device will not register a break in driving until the ignition is off. (The exception is the G120, which can be configured to register a break if idling is detected) Otherwise, if the device is configured for movement trips only, it will not register a break in driving until the movement trip end time elapses.


Setup on OEM Server:

Buzzer Parameters

See Common Concepts - Buzzer/LED Setup. If we want to sound an external buzzer, we must configure one of our Digital Outputs as function Buzzer - then we can wire the low side to this output wire. 

Dart2/G100 Params

Behaviour shown above:

  • Once a trip starts, fatigue timer begins
  • Warning period - After 105 min (1hr 45)
    • 5x beeps are sounded - 1 second each beep (1s beep, 1s silence x 5)
  • Alert Period - After 135 min (2hrs 15 min)
    • 10 x beeps are sounded - 1 second each beep (1s beep, 1s silence x 10)
    • Digital Output 1 and 2 are activated (they could be wired to an LED to provide visual feedback to the driver that they need to take a rest stop). To use these outputs, we need to configure as follows:


G120 Params

On the G120, we have the option to adjust the dropdowns to increase the timeout. The max warning period value that can be configured is 255 (i.e. 255 min = 4hrs 15).
We can adjust the dropdown to extend this 5x


Setup Example

  • We have a mandated requirement where drivers must not drive for longer than 5hrs 15 min continuously - they must take a 15 minute break.
  • We want to send a warning alert after 5hrs
  • We need to send the fatigue alert after 5hrs 15 min
  • Drivers don't bother to ignition off when they stop for a 15 min break (that would make life too easy for us) - so we want 15 min of the truck being stationary to reset the timer.
  • We want to run a report of 'fatigue violations' in TG (or another system)

  1. Fatigue warning period of 60 x 5 min = 300 min = 5hrs. Buzz 5 times when reached
  2. Fatigue alert period of 63 x 5 min = 5hrs 15. Buzz 10 times
  3. When we have been driving continuously for >5hr 15 min - set Digital Input 11 active on the device and turn on an output (say for a light)
  4. Reset the timer if Idling is detected.
    We configure our 15 min idle period (15 min stationary break) as follows:


This achieves all our objectives. Now, in TG or another platform, we can just run a report on whenever Digital Input 11 was active to get our 'violation' report.

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