The type of encoder will determine the number of wires necessary to enable the sensor to communicate with the readout device (controller, drive, counters/display, etc.). Incremental encoders will require one wire for power, one wire for ground, and one wire for each additional channel. Incremental encoders are available in a variety of types including:

• Single-channel encoder designs (A channel) to track speed and displacement
• Quadrature encoder designs (A and B channels), which also track direction
• Quadrature encoder designs with an additional index channel (Z channel) to establish a home position once per revolution
• Encoders with additional commutation tracks (U, V, and W channels)

For high-noise environments, a differential encoder may be an appropriate solution. In these designs, a differential line driver generates two outputs for each channel: the normal signal and its complement. Any noise spikes will appear in each signal, enabling the receiver to filter it out as common-mode noise. Implementing this scheme requires two wires for each channel.