Driver Working State Filters

Configuration

N/A driver state – If parameter is disabled, the device will not save data about current minute, if driver information are not available. System bypassed to report incorrect or incomplete data.
(Parameter ID: 253)

Deny driver working state when ignition off – If parameter is disabled, device will reject driver information when vehicle ignition is turned off.
(Parameter ID: 254)

OneMinute Rule - if parameter is disabled, device will continue analyzing driver data but results will not be saved and records with data will not be generated (enables or disables rule 038).
(Parameter ID: 252)

SMS/GPRS Commands

tacho_dbg:x, where x = 0,1

This command allows to enable or disable basic debug information.

Response for the command: Set tacho data monitor dbg:0

getparam x, where x = configurator parameter (252,253,254)

This command allows to check the value of configured parameters.

Response for the command: Param ID:252 Value:1

setparam x:y, where x = configurator parameter (252,253,254), y = value to write

Command allows to set value to Configurator parameter. Available value 0,1.

Response for that command:

Config same for 252: 1 – information that parameter was configured before with the same value.

Failed to update parameters – there was an error during setting parameter. Value of the range.

New value 252:0 – parameter configured successfully. Received information what value has been set to specific parameter.

OneMinute Rule

The One Minute Rule is for situations when a driver is on a rest period but needs to move the vehicle briefly, for example, to clear a passage for another vehicle. Under normal circumstances, starting to move the vehicle would reset the rest period, potentially affecting the driver’s working time calculation. The One Minute Rule allows such short actions without interrupting the rest period, under certain conditions.

How it works:

The tachograph analyzes the entire minute and determines which activity occupied the longest duration.
If the driver moves the vehicle for less than 30 seconds within a minute, the device considers the dominant activity as rest, not driving.
As a result, the full minute is counted as part of the rest period, and the driver does not need to restart the break.

Benefits:

Ensures a realistic recording of the driver’s working and rest times.
Allows brief vehicle maneuvers during a rest period without formally interrupting it.
Simplifies activity reporting and prevents unintended violations of driving time regulations.

Tachograph Functional Rules

Rule 038 – One Minute Rule

Rule 038 defines how tachographs record the driver’s activity in 1-minute intervals. Instead of storing activity changes second-by-second, the tachograph processes all activity signals within the current minute and determines which activity was dominant.

Logic:

The tachograph counts the number of seconds spent in each activity within the minute:
- Driving
- Other Work
- Availability
- Rest/Break
At the end of the minute, the device selects the activity with the longest duration.
The entire minute is recorded as that dominant activity.

Example:

22 seconds of driving
38 seconds of rest

The stored minute will be recorded as Rest.

This mechanism allows short movements during breaks without resetting the rest period.

Rule 040 – Priority of Driver Activities

Rule 040 defines the priority hierarchy of activities when multiple activity inputs or triggers occur at the same time. It determines which activity should be applied immediately when conflicting signals are detected. Activity Priority (highest to lowest):

Driving
Other Work
Availability
Rest/Break

What this means:

If the tachograph detects vehicle movement, it must switch to Driving, regardless of what the driver selected manually.
Manual selections can be overridden by activities with a higher priority level.
This ensures consistent and legally compliant detection of driving activity.

Example:

The driver sets Rest manually. If the vehicle moves for a few seconds, the tachograph will then switch to Driving (highest priority).

Rule 041 – Handling Activity Changes Within the Minute

Rule 041 describes how tachographs monitor, count and buffer all activity transitions occurring within the current minute. It provides the detailed second-level data needed by Rule 038 to decide the dominant activity.

Logic:

The tachograph keeps an internal second-based counter of each activity during the minute.
It records all transitions, even if they last only a few seconds (e.g., short manoeuvres).
At the end of the minute, these counters are passed to Rule 038 for dominant-activity evaluation.

Example:

Within one minute:

5 s driving
7 s rest
3 s driving
45 s rest

Internal counters (Rule 041) determines:

Driving = 8 s
Rest = 52 s

Rule 038 records the minute as Rest.

Rule 042 – Special Activity Handling

Rule 042 defines additional logic for handling special or exceptional driver activities within the tachograph system. Purpose:

Handle specific activity scenarios requiring immediate or exceptional processing.
Override or modify activity states in special cases, such as emergency maneuvers or system-triggered events.
Ensure accurate reporting in situations not fully covered by standard activity rules.

Logic:

The tachograph monitors the current driver state and system inputs.
If a special condition occurs, Rule 042 may:

Override the dominant activity determined by other rules.
Force a predefined activity to be recorded for the minute or sub-minute interval.

Example:

The driver is on a rest period, but an emergency maneuver is detected.
Rule 042 may temporarily record the activity as “Driving” for safety or legal compliance, even if Rule 038 would normally store “Rest” for that minute.

Benefits:

Ensures critical or exceptional activities are accurately recorded.
Enhances compliance with regulatory requirements in non-standard situations.
Provides flexibility for system designers to handle edge cases without impacting the normal minute-by-minute recording logic.