What information should I send for encoder selection?
Send the existing model, machine application, controller interface, supply, resolution, turn range, shaft or bore, flange, connector, cable length, environment and quantity.
Technical selection, cross-reference and global export supportSend a model or application →
Encoder selection guide
How to choose an industrial rotary encoder
A practical selection sequence covering measurement type, resolution, interface, mechanics and environment.
DIRECT ANSWER
Choose a rotary encoder by defining the measurement task before comparing models. Confirm absolute or incremental feedback, single-turn or multi-turn range, resolution, controller interface, supply, maximum speed, shaft and flange, protection rating and required drawings. A model is not compatible until both electrical and mechanical details match.
✓ Measurement type and power-up behavior✓ Resolution and turn range✓ Controller interface and supply✓ Shaft, flange, speed and environment
SELECTION TABLE
Eight rotary encoder selection factors
Use this table as an initial engineering checklist. Final model configuration must be confirmed against the controller, mechanical drawing and operating environment.
FactorQuestion to answer
MeasurementSpeed, relative position, absolute angle or multi-turn position?
ResolutionWhat smallest movement must the control system distinguish?
InterfaceWhich PLC, drive or controller input is available?
MechanicalWhat shaft, bore, flange, space, coupling and maximum speed apply?
EnvironmentWhat temperature, vibration, water, dust, salt spray or hazardous-area requirement applies?
DocumentationAre a controlled drawing, wiring file, protocol manual or certificate required?
ENGINEERING PROCESS
How to select the right configuration
- 01
Describe the movement and required machine behavior after power loss.
- 02
Calculate resolution and total turn or travel range.
- 03
Match the controller interface, output circuit, supply and update rate.
- 04
Confirm housing, shaft, flange, connector, speed and shaft loading.
- 05
Define environmental protection and certification requirements.
- 06
Approve the complete model suffix, drawing and wiring before ordering.
RELEVANT PRODUCTS
Technical product pages
RS485 Modbus RTU Absolute Rotary Encoder
Single-turn or battery-free mechanical multi-turn absolute position feedback with power-off memory and programmable Modbus RTU parameters.
View parameters and drawings →
Industrial Incremental Rotary Encoder
Configurable pulse feedback for speed, direction, counting and relative position measurement.
View parameters and drawings →
Servo Motor Spindle Absolute Encoder
High-precision optical-grating absolute feedback for servo motors, CNC spindles and precision drive systems.
View parameters and drawings →COMMON QUESTIONS
Frequently asked questions
Can two encoders with the same diameter replace each other?
Not automatically. Shaft geometry, flange pattern, mounting depth, supply, output, protocol, pinout, scaling and environmental rating must also match.
How much encoder resolution do I need?
Required resolution depends on the mechanical ratio, desired machine resolution, control margin and system accuracy. More bits or pulses do not correct backlash, mounting error or mechanical flexibility.
RELATED GUIDANCE
Continue your selection
EDITORIAL SCOPE
How this guidance is prepared
FOSAI consolidates available supplier technical material into a buyer-oriented selection guide. Parameters, certifications and compatibility are not generalized across every model; the final suffix, controlled drawing and project conditions must be confirmed before ordering.
MODEL SELECTION SUPPORT
Send the model.
We’ll check the complete fit.
Include the existing model, controller interface, supply, measurement range, shaft or mounting drawing, environment and quantity.
Request technical selection →