Haltech E6X Manual DOS Version - Manual (Page 119)

E6X Manual
119
effect trigger. The reluctor adaptor and its tuning is dealt with in detail in 4.2.3 Ignition Set-
up Page, p46.
E.2 Trigger Angle
The trigger angle is simply the angle before top dead centre (BTDC) at which the trigger
event occurs. The trigger device used must produce at least one trigger event for each ignition
event and each trigger must occur a constant angle BTDC. See Appendix E.6 Trigger Type
E.3 Trigger Edge
The ECU uses the signal transitions from low to high called rising edges and high to low
called falling edges to determine engine position, these transitions occur at specific angles
across the rotation of the crank (half cycle) or cam (full cycle). In most instances the ECU
will only uses one type of transition (rising or falling) for a trigger and this is known as the
Trigger Edge.
In the example 2(a) shown below the trigger occurs on a rising edge at 70° BTDC. The
second edge, a falling edge, could occur any time after the rising edge, in some installations
the second transition will coincide with 10° BTDC or TDC. This second edge will have no
effect on the operation of the ECU. It is only the position of the triggering edge that is of
importance. Example 2(b) shows the same trigger angle but with the opposite trigger edge.
Falling Edge
Rising Edge