Technology Blog

When sizing a motor for a robot, there are two kinds of torque that you should pay attention to: the peak torque the motor must deliver at the highest load of the move and the continuous torque it must sustain over the whole duty cycle. Get the first wrong, and the robot lags, faults or drops its payload. Get the second wrong, and the motor runs hot and trips on thermal faults hours into a shift, long after it passed every bench test.

Semiconductor equipment like wafer-handling robots, precision inspection stages and packaging equipment have high-performance motion requirements. Here we explain how absolute encoders enable the fast, smooth motion, fault recovery and reliability necessary in semiconductor handling and which absolute encoder types suit each axis.

Newer absolute encoder interfaces can cut wiring to two conductors, carry functional safety data alongside position and run at Ethernet speeds. They also differ in licensing, power requirements and how widely they are used, so the right choice depends on your motor, drive and safety needs. In Part II we review EnDat® 2.2, EnDat 3, HIPERFACE®, HIPERFACE DSL, Absolute-A™ and DRIVE-CLiQ® and compare all eight interfaces.

The interface between an absolute encoder and a servo drive does more than carry position data. It sets how quickly that data reaches the servo loops, whether the drive can read the encoder's memory and how errors are detected. If you choose an interface with too much latency, the servo loop stability suffers.

Visit Copley Controls at SPS 2026 in Nuremberg, Germany. Explore servo drives, motion controllers, robotics solutions, EtherCAT networking, encoder integration, and schedule a one-on-one technical meeting.

Choosing an absolute encoder involves three decisions: how the encoder senses position, how it is built mechanically and how it communicates with the servo drive. The serial communication protocol is the decision most often left until late in a design. It is also the one that most often causes trouble.