The standard output is two channels in quadrature (A and B) along with an index (Z). The index type can vary, but the most common one in North America is “gated with negative B” as shown in the diagram. Including the complimentary signals A/, B/, and Z/ (not shown in the diagram) means that a minimum of six data lines, plus power, plus signal common are required to operate the encoder. On the right hand side, an absolute encoder output is shown. Since absolute encoders can have up to 16 bits (65,536 unique 16-bit codes), it is easier to send the signal serially. This data is synchronized by the user’s system clock. Each tick of the clock opens a gate to let one bit of information through. When all the bits have been clocked in, the controller knows the exact position of the encoder. To reduce common-mode noise, the data and clock lines are paired. Adding the power and signal common makes for a total of six wires.