ERN 1123
Incremental rotary encoder with integral bearing
- Axial tolerance of up to ±0.15 mm
- Hollow through shaft
- Positioning accuracy of down to ±130″
- Up to 8192 signal periods per revolution
- Max. operating temperature: 90 °C
- Interface: TTL
- Housing diameter ≈ 35 mm

Direct shaft coupling
The hollow shaft allows the rotary encoder to be directly coupled to the mating shaft. An additional rotor coupling is not required. The resulting high rigidity permits higher bandwidths in the control loop, reduces inaccuracy, and simplifies installation.
Block commutation signals
Along with TTL signals, the rotary encoders of this series also output U, V, and W block commutation signals for direct commutation control. These rotary encoders can therefore be used directly on most downstream electronics for motor control.
Flexible coupling
The stator coupling compensates for play between the motor and the rotary encoder, thereby reliably correcting inaccuracy. Even tilt and axial play can be compensated for. The stator coupling also facilitates easy mounting onto the plane surface.
Compact design
The encoders of this series feature high ruggedness and reliability in a compact design, with an outer diameter of just 35 mm. Their small footprint makes them ideal for tight installation spaces.

