Speed signal "Tiny Cooling Fan" circuit output from the normal form of pulses, each wave is represented with the fan turned around, this signal may be provided directly to the host for display via the data bus. Some outputs of the fan speed signal is not "Tiny Cooling Fan" true speed, but speed multiples, for example once per revolution and two, four or six pulses, must be treated in order to reflect the formation of a true fan speed signal. To distinguish "Tiny Cooling Fan" speed is real or a multiple of the speed, you can use the tachometer to measure the actual speed, and then compare with the data displayed.