What do phase A, phase B and phase Z of the encoder refer to?

The encoder manufacturer shows that the encoder only has the concept of A-phase, B-phase and Z-phase signals. A-phase, B-phase and Z-phase are the output signals of the encoder's channels, and the so-called U-phase, V-phase and W-phase are the three-phase main circuit supplies of the AC motor's main power supply. In the encoder's A-phase, B-phase and Z-phase signals, the signals of A and B channels are generally quadrature pulse signals; while the Z-phase is zero pulse signal. Generally the encoder output signal in addition to the A, B two-phase, every revolution also output a zero pulse Z. When the spindle rotates clockwise, the output pulse A channel signal is located before the B channel; when the spindle rotates counterclockwise, the A channel signal is located after the B channel. Thus, it can be judged whether the spindle is rotating positively or negatively. In addition, the encoder sends out one pulse for every one week of rotation, which is called the zero pulse or marking pulse, and the zero pulse is used to determine the zero position) or marking position. To accurately measure the zero pulse, regardless of the direction of rotation, the zero pulse is used as the basis for two...