https://docs.emtronaustralia.com.au/engine-management/config/ignition/ignition-firing-edge/index.htmlIgnition Firing Edge Sets the edge at which the ECU commands the coil to be fired. Nearly all modern coils have a build-in ignitor module and use a falling spark edge. Warning - Ensure the correct edge for the ignition system is selected before connection to the coils. Damage may occur to the ECU and/or the ignition system if the wrong edge is selected.Hugoen-us