Servo motor encoder of this basic functionality is the same as with ordinary encoder, such as absolute are A, A trans, B, B trans, Z, Z and other anti-signal, in addition, there is a servo motor with encoder Common encoder different places, that is, the servo motor encoder mostly synchronous motor, synchronous motor startup needs to know the pole position of the rotor, so as to high torque start servo motor, which requires additional with a few signals to detect the rotor current location, such as the incremental UVW there other signals, is because of these signals, the servo encoder detects the position of the rotor is a little complicated, so most people do not understand the truth of it, plus some manufacturers intentionally Yanzhe some signals, the relevant information is not complete, it added more servo motor encoder mystery.
　　Since the A, B two-phase difference of 90 degrees, the first phase A or B by comparing the first phase, in order to determine the encoder forward and reverse, the zero pulse can be obtained encoder zero reference position.
　　Encoder code disc material glass, metal, plastic, glass code discs are deposited thin engraved lines on the glass, good thermal stability, high accuracy, metal code disc directly through the barrier and engraved lines, non-friable, However, since the metal has a certain thickness, there are restrictions precision, thermal stability is necessary an order of magnitude worse than glass, plastic code disc is a economical, low cost, but the accuracy, thermal stability and life are to be worse .
　　Resolution - 360 degrees per encoder rotation through or how much dark groove called the resolution, also known as analytic indexing, or direct say how much wire, usually 5 degrees per rpm to 10,000 lines.