AiM MXL2 - Manual (Page 7)

CHAPTER 6 RPM
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MXL2
6. RPM
MXL2 can receive the RPM signal from three different sources:
n From ECU
n Through a square wave signal (8 to 50 V)
n From the low voltage (from 150 to 400 V)
of the coil
6.1 RPM from ECU
To get RPM from the ECU please configure your MXL2 and enable RPM channel as explained
in section 10.1. RPM is one of the many data flowing from your ECU to MXL2.
6.2 RPM via a 5-50 V Square Wave Signal or coil (150-400 V)
In case your engine is not managed by any ECU, MXL2 can read the signal from the low voltage
of the coil (whose peak can be from 150 to 400 V) or from a possible square wave (the peak
can be from 5 to 50V). The pin labelled "RPM" reported in appendix “Pinout” receives the
signal:
The image shows an example of wiring for
the ignition system.
The output, labelled “GREY TACH” gives a
5-50V output that can be directly acquired
from MXL2 If the output is not available
from the ignition system, the system has to
be connected to the low voltage of the coil,
as shown in the following schematic.
Point 1: Low voltage of the coil
Point 2: Connected to the spark plug
Point 3: Connected to the +12V of the
battery
After connecting the RPM signal, please use
the software RaceStudio3 for enabling the
RPM channel, as explained in section 10.1.2
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