Odometer Pulse Length

For Certus to use a wheel speed sensor or odometer input, it must know the pulse length of the signal. The pulse length is the distance in metres between low to high transitions of the signal. By default, the odometer will automatically calibrate itself. To automatically calibrate the odometer pulse length, see Calibrating Odometer Automatic Pulse Length.

Calibrating Odometer Automatic Pulse Length

  1. Ensure that the signal is connected correctly and that the GPIO pin is configured as an odometer input using the GPIO page in the web UI or the GPIO dialogue in the Certus Manager.
  2. Wait until Certus has a continuous GNSS fix and then conduct the test in an area with no obstructions over the test circuit.
  3. Open Certus Manager, connect to Certus and open the Odometer Configuration dialogue. In the Odometer Configuration dialogue select the Automatic pulse length calibration check box and click Save.
  4. If Certus loses a GNSS fix for any extended period of time during the calibration, the distance travelled will be reset. The distance travelled can be checked in the Odometer Configuration dialogue to ensure that it has passed 1,000 metres.
  5. Once 1000 metres has been driven, check that the automatic pulse length check box has become un-ticked and the Pulse Length value has changed. This indicates a successfully completed calibration.

Note: To enter the pulse length manually, use the Odometer page in the Configuration menu in the Certus Manager.

Note: Maximum speed that can be processed by Certus is 216 km/h. If the maximum speed is exceeded, the Odometer Automatic Pulse Length Calibration will reset. Calibration will restart once speed drops below the maximum speed.