Installation Manual

11 Appendices

11.1 Appendix A: Capturing Vehicle Data

11.1.1 Capturing Odometer and Engine Hours Information

If the FJ3 is to record the vehicle's odometer, you will need to obtain a pulse relevant to the

vehicle’s speed. You can accomplish this either by utilizing an Odometer Adaptor or by

receiving electronic pulses from the vehicle speed sensor (VSS) output. If your vehicle has a

cable driven speedometer, a transducer is needed to convert the mechanical turns of the

speedometer cable into electronic pulses that the FJ3 can read. Transducers may be ordered

through a local speedometer repair shop, through the vehicle manufacturer's parts distributor,

or directly from the sensor manufacturer.

11.1.2 Vehicle Data Collection (VDC) - Option

The Roseman VDC enables online wireless capture of odometer and/or engine hour readings

from vehicles equipped with the Roseman Vehicle Identification Fleet Gate (FJ3). This data

capture occurs when a vehicle passes within range of the Wireless Automated Fueling (WAF)

Receiver installed in a parking area or at a fuel island. The vehicle data is transmitted to a local

PC, which has the Roseman proprietary VSU application, and will transmit it to the

FleetFocus™ application server via TCP/IP protocol.

11.1.3 Vehicle Speed Sensor (VSS)

For FJ3 pulse counting to function properly, it requires an accurate speed signal from the

vehicle. This section provides a quick overview of what a speed signal is, and how to identify

a speed signal.

With the introduction of the electronic control module (ECM/ECU) found in all modern vehicles,

engineers use sensors to report operational data to this computer for processing.

In most cases, the vehicle’s speed signal is generated at the transmission output shaft. The

shaft turns at a speed directly proportional to the vehicle speed. Two different sensor types are

commonly found at this location. The most common type is called a variable reluctance sensor.

This is a fancy name for a series of magnets mounted to a shaft, which spins past an inductor

or coil. A voltage or pulse is induced in the circuit as the magnets’ lines of force cut through the

inductor. The result is a signal that pulsates or oscillates at a speed directly proportional to

vehicle speed. The more modern but less common type of sensor is the Hall Effect sensor,

which works like the variable reluctance sensor, uses a tiny solid-state switch that is activated

by a magnetic force. This result is a smaller and lighter sensor, generating a cleaner signal.

There are many ways to identify the vehicle speed signal:

11.1.3.1 Using an Oscilloscope

Using an Oscilloscope is the easiest way to view and identify the VSS signal. It

shows a picture of the signal.