Tachometer: Description and Operation

Tachometer:

The tachometer display is controlled by a stepper motor measuring mechanism actuated by a stepper motor driver. The input signal is provided by the Engine Control Module (ECM). A tachometer pulse factor is stored in the Electronically Erasable Programmable Read Only Memory (EEPROM) for conversion or the input frequency into revolutions. Range: 1.50 to 655.35 pulse/revolution, resolution: 0.01 pulse/revolutions. At a tachometer pulse factor less than 1.50 pulse/revolution, the instrument behaves as in the case of EEPROM not programmed. The maximum display angle is 115.5 degrees of pointer sweep and has a display tolerance for accuracy of +/- 2.4 degrees.