MoTeC MDC2 - Manual (Page 6)

MoTeC MDC2 4 Functionality
When wired directly to the MDC2, the wheel speed inputs can be configured as hall effect or magnetic sensors
with adjustable thresholds, and individual sensors can be enabled or disabled. Magnetic sensor input thresholds
are individually configurable for front and rear sensor pairs according to the current front and rear speeds.
The speed calibration can be adjusted for different wheel sizes and sensor teeth.
Front, rear and vehicle speeds are calculated from the wheel speeds, and all speeds are transmitted in CAN
messages. These speeds can be logged by the MoTeC ADL (Advanced Dash Logger), or used in logging or
engine control strategies by the MoTeC M800 ECU.
For information on configuring speed inputs, see Setup | Input Setup in the MDC2 Manager section.
Speed Calculations
The method of calculating front, rear and vehicle speeds is dependent on the status of the brake input.
When the foot brake is applied, speeds are calculated as follows:
• Front Speed is the faster of the two front wheel speeds.
• Rear speed is the faster of the two rear wheel speeds.
• Vehicle speed is the faster of the calculated front speed and rear speed.
When the foot brake is not applied, speeds are calculated as follows:
• The front speed is the average of the two front wheel speeds, weighted 80% towards the slowest front
wheel speed. If one front wheel speed is less than half of the other front wheel speed, then front speed is
simply the faster of the two front wheel speeds.
• The rear speed is the average of the two rear wheel speeds, weighted 80% towards the slowest rear
wheel speed. If one rear wheel speed is less than half of the other rear wheel speed, then rear speed is
simply the faster of the two rear wheel speeds.
• The vehicle speed is the average of the front and rear speeds, weighted 80% towards the slowest speed.
If either the front or rear speed is less than half of the other speed, then vehicle speed is simply the faster
out of the front speed and rear speed.
If any wheel speed exceeds 300km/h, the sensor reading is ignored until its speed returns to below 300km/h for 2
seconds. This is to prevent erratic behaviour from noisy wiring or faulty sensors.
Handbrake Override
If the front wheel speed is 0km/h and the handbrake is active, the handbrake will then be ignored in all lock
calculations until the handbrake is released. This functionality allows the diff to be locked in preparation for takeoff
during a handbrake start.
Throttle Calibration
The throttle position is received on the CAN bus from the ECU, or a throttle position sensor can be optionally
wired directly to the MDC2.
The optional throttle position sensor input can be calibrated using a table to convert voltage to throttle position.
This allows non-linear calibration of throttle position to more closely model the change in torque vs. throttle
butterfly angle.
The MDC2 Manager configuration program allows throttle input voltages to be read directly from the MDC2 in
order to perform 0% and 100% calibrations.
For information on calibrating the throttle input, see Setup | Input Setup in the MDC2 Manager section.
Steering Position Measurement
The steering position is received on the CAN bus from the steering position sensor.