Single-turn absolute encoders output a unique digital code for every shaft position within one complete revolution - typically 12-bit (4,096 positions) to 17-bit (131,072 positions) resolution. Unlike incremental encoders, no homing or reference travel is required after power interruption - the encoder reports exact position immediately on power-up, regardless of what happened to the shaft during the power-off period. This retained position capability is essential where shaft movement during a power loss or emergency stop could leave the machine in an undefined state requiring a homing cycle before restart. Absolute encoders eliminate this requirement, enabling faster and safer restart sequences that can represent significant savings in cycle time on high-throughput machines. Interface options include SSI, parallel binary, Gray code, CANopen, Profibus, Profinet, EtherCAT, DeviceNet, and analogue 4-20mA or 0-10V outputs for integration into all common industrial control platforms. Solid shaft, hollow shaft, and blind hollow variants in standard and stainless steel housings with IP65 to IP67 sealing cover all standard installation requirements. Single-turn absolute encoders are the correct choice for valve positioning systems (where position must be known on restart), rotary index tables, robotic joint angular position, medical device axes, and machine tool axis homing elimination. For applications spanning more than one shaft revolution where the full travel must be tracked, a multi-turn absolute encoder is required instead.
