Haltech E6M - Manual (Page 136)

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The S2/S4 Hall Effect Sensor
The S2 and S4 Hall effect sensors differ slightly in their electrical characteristics but are
functionally identical when used in conjunction with the E6H or E6M. If you are using an S4
sensor follow the direction below for the S2 sensor. The S2 sensor can be identified by a
black cable gland. The S4 sensor is identical in appearance but has a black stripe on the grey
cable.
As a south pole passes the sensor face the signal in the secondary (PIN D) channel is
switched to a low state. As a north pole passes the sensor a low state will only occur on the
primary channel (PIN C).
The set-up for this sensor is similar to the S1/S3 except that one extra magnet is required as
well as the orientation being changed. The north pole of the magnet is used to generate the
main trigger while a south pole is used to generate the home or synchronisation pulse.
Typical set-ups - S2/S4
4 cylinder / 2 rotor engine
For a four cylinder 3 magnets are required in total. Two north poles positioned exactly 180
°
apart while a south pole needs to trigger the sensor before the trigger for cylinder No 1. The
positioning of the magnet for cylinder one is done the same way as the for the S1 making sure
the north pole is triggering the sensor at approximately 75
°
BTDC.
FIGURE 4: TYPICAL 4 CYLINDER/ 2 ROTOR APPLICATION
6 CYLINDER / 3 ROTOR ENGINE
For a six cylinder 4 magnets are required in total. The three north poles are positioned exactly
120
°
apart while a south pole need to trigger the sensor before the trigger for cylinder No 1.