Basic parameters of the encoder

Resolution

Resolution defines the minimum distinguishable displacement unit of an encoder.

• For incremental encoders, resolution is specified as PPR (Pulses Per Revolution), equivalent to the number of transparent grating slits (line count) on the code disk. Common specifications span 5–6000 PPR, representing 5 to 6000 pulses generated per full shaft rotation.When matched with a reducer of ratio n, total pulses per output shaft rotation = encoder PPR × reduction ratio.Example: An 11-PPR encoder paired with a 270:1 reducer yields 11 × 270 = 2970 pulses per output shaft revolution.

• For absolute encoders, resolution is measured in bits, split into single-turn and multi-turn resolution, corresponding to the number of binary code tracks on the code disk.

Precision

Precision and resolution are distinct technical metrics. Precision stands for the maximum deviation between the encoder’s measured value and the real shaft position, quantified in degrees, arcminutes or arcseconds.Example: A parameter marked ±20" means the position reading carries a maximum error of ±20 arcseconds.Precision is affected by code disk lithography accuracy, shaft concentricity, material thermal expansion and circuit response latency.

Maximum Response Frequency

It denotes the maximum pulse output volume per second (unit: Hz).Calculation Formula: Max Response Frequency = Resolution × Rotational Speed ÷ 60

Signal Output Type

• Incremental encoders provide independent signals for each channel; mainstream circuit types include open collector, push-pull and differential line driver outputs.

• Absolute encoders transmit multi-bit position codes. Serial or bus communication is widely adopted to guarantee transmission speed and anti-interference performance, including SSI, RS485, CANopen and EtherCAT. A small portion adopts parallel output with the same circuit forms as incremental encoders.

Maximum Rotational Speed

It refers to the top mechanical rotating speed the encoder hardware can sustain.