Inside the user manual we can find things regarding signals, speed sensing, speed sensor frequency, and measurement method. Lots of things about speed sensors, sensor, frequency signal, and input are described inside this user manual.
The user manual tells you explanation about ignition, measurement, resolution, and frequency speed sensor. The following are excerpted from the user manual:
The following tables show the functionality of each of the 4 inputs of the SSI-4 (the default factory settings of the SSI-4 are highlighted: Input Function 1 Function 2 Function 3 Channel 1 Frequency (straight frequency, Speed sensor) External 0..5 Volt Channel 2 RPM (programmable Range, default 0..10230 RPM, 4 Cylinder) Duty Cycle External 0..5 Volt Channel 3 N/A Frequency (straight frequency, Speed sensor) Frequency (straight frequency, Speed sensor) Frequency (straight frequency, Speed sensor) Channel 4 External 0..5 Volt External 0..5 Volt The SSI-4 also can act as a power supply for user supplied external sensors.
Also, the user manual explains information regarding speed sensor, sensor signals, sensors, and ignition system.