FMC650 - Tachograph data via FMS

Telematics Question
1

Hello,

We are using the FMC650 connected to the truck’s tachograph via the FMS connector (CAN bus).

We are currently developing a fleet management platform and we rely on tachograph data fields such as:

  • Driver 1 Activity (driving, rest, work, availability)

  • Driver 1 Cumulative Break Time

  • Driver 1 Driving Time (continuous, daily, weekly)

  • Driver 1 Last Daily Rest

The issue: We only receive these tachograph data fields when the vehicle’s ignition is ON. As soon as the ignition is turned OFF, the FMC650 stops sending any tachograph-related data.

However, the digital tachograph itself remains powered and the driver can still manually change their activity status (e.g., switch from driving to rest) even with the ignition off.

Our questions:

  1. Is there a way to configure the FMC650 to continue reading tachograph data from the FMS/CAN bus when the ignition is OFF?

  2. Does the tachograph continue to broadcast data on the K-Line or CAN bus when the vehicle’s ignition is OFF, or does the bus shut down entirely?

  3. Is there any alternative wiring or configuration (e.g., permanent power on the CAN line) that would allow us to receive tachograph status changes in real time, even with the engine off?

Any guidance would be greatly appreciated. Thank you.

2

Good day,
Thank you for your query.

  1. No, there is no generic FMC650‑only configuration that will keep reading tachograph data over CAN when the vehicle’s CAN network and/or tachograph stop responding with ignition OFF. That behavior is mainly dictated by the truck and tachograph.

  2. Yes, the tachograph often continues to provide data briefly via K-Line after ignition OFF, and front-panel K-Line can sometimes work even with ignition OFF, depending on licenses/settings.

  3. Best‑effort setup for your use case:

    1. Power FMC650 from constant battery, ignition as input only.

    2. Disable param 254 (“Deny Driver working state when ignition is OFF”).

    3. Add and enable K-Line as a Live DATA source; use front-panel K-Line if available.

    4. Coordinate with a tachograph workshop to:

      • Enable auto‑REST on ignition OFF (if supported), and/or

      • Extend CAN/K-Line availability with ignition OFF where possible.

Kind regards,
Muhammad A