Tachometer Output

Overview

The ECU may be configured to output a tachometer signal to drive an external tachometer. The signal is a square wave with a frequency proportional to the engine speed.

Tacho Edge Table

Tachometer state change events are inserted into the table iconTacho Edge table. They should be evenly spaced and typically there should be 4 state changes per revolution (i.e. 2 pulses per rev), depending upon the tachometer input requirements.

It is generally best, therefore, to place the state changes at the same channel iconA Tooth numbers as equidistant ‘active edges’ in the tooth control table, assuming that it is possible to do so.

The option iconTacho Pin option specifies which ECU pin the tachometer signal is output from. Check the ECU pinout to determine which pin number this should be set to.

Note

Changing the Tacho Pin option requires an ECU reset to take effect.

If using the RPM Pickup wizard, the Tachometer output can be calculated for you given a pulse-per-rev value. The RPM Pickup wizard assumes that option iconWheel Teeth is equal to the number of internal teeth.