Optical incremental encoder
Hengstler ICURO RI58 optical incremental encoder
Universal 58 mm incremental encoder family with up to 10,000 lines (up to 40,000 steps with edge evaluation), IP67 and many flange and connector options; hollow-shaft RI58-H takes shafts up to 12 mm and the RI58-T runs to 100 °C.
Key specifications
| Bore (max) | 12 mm |
|---|---|
| Ingress protection | up to IP67 |
| Temperature (max) | 100 °C |
| Supply | 3–38 V wide-range option (on request) |
| Ppr max | 10,000 |
| Counts max | 40,000 |
| Temp note | 100 °C for the RI 58-T; RI58-H rated -10 to +70 °C |
| Shock | RI58-H: 100 g (1,000 m/s²) for 6 ms |
| Housing | 58 |
Summarised in our own words from Ralliant Corporation (Hengstler GmbH, part of Hengstler-Dynapar)'s published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1 · Source 2 · Source 3
Notes on this data
RI58-H uses Hengstler's isolated opto-ASIC scanning (news page). Explosion-protected applications are referred to the RX 70-71 range.
Specify Motion is not affiliated with Ralliant Corporation (Hengstler GmbH, part of Hengstler-Dynapar). Hengstler and ICURO RI58 are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Typical applications
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Our experienced engineers are on hand, ready to help with your project. Whether you need the Hengstler ICURO RI58 itself, help sourcing it, or a modified or custom design built around your load, speed and space, tell us what the machine has to do and we'll come back with the right option.
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What an optical incremental encoder is
An optical incremental encoder measures motion by shining light through or reflecting it from a disc or scale with fine graduations onto photodetectors. As the disc or scale moves, the encoder outputs two square-wave or sine-wave channels in quadrature, called A and B, plus an index pulse once per revolution or at reference marks. The counter in the drive or controller tracks position by counting edges from a home point. Optical encoders achieve very high resolution and accuracy.
When engineers choose an optical incremental encoder
Choose an optical incremental encoder for precise speed and position feedback where homing at power-up is acceptable, such as servo motors, stages and machine tools. They are widely compatible and cost effective. The trade-offs are contamination and power loss: dust, oil and condensation can obscure the optical path, and position is lost when power is removed. For harsh environments, magnetic or inductive encoders may suit better.
How to specify the Hengstler ICURO RI58
Send these with your enquiry and an engineer can confirm the right ICURO RI58 variant or an equivalent:
- Resolution (lines per revolution or µm)
- Output type: TTL, HTL or sin/cos
- Index or reference marks
- Shaft or hollow shaft size (mm)
- Maximum speed (rpm or m/s)
- Supply voltage (V)
- Environment and IP code
Common mistakes to avoid
- Choosing resolution above what the drive input can count
- Running long cables with TTL signals without line drivers
- Ignoring contamination in open optical designs
- Forgetting homing routines after power-up
Hengstler ICURO RI58: frequently asked questions
What is the Hengstler ICURO RI58?
Universal 58 mm incremental encoder family with up to 10,000 lines (up to 40,000 steps with edge evaluation), IP67 and many flange and connector options; hollow-shaft RI58-H takes shafts up to 12 mm and the RI58-T runs to 100 °C. Published series figures include bore 12 mm, temperature 100 °C. It is made by Ralliant Corporation (Hengstler GmbH, part of Hengstler-Dynapar); Specify Motion can help source it or propose an equivalent.
Who makes the Hengstler ICURO RI58?
The Hengstler ICURO RI58 is made by Hengstler (Ralliant Corporation (Hengstler GmbH, part of Hengstler-Dynapar)) and is listed here for engineers comparing options. Specify Motion is not affiliated with Ralliant Corporation (Hengstler GmbH, part of Hengstler-Dynapar); brand names are used only to identify the product.
What is the bore of the Hengstler ICURO RI58?
The published series maximum bore is 12 mm. Individual models and sizes in the ICURO RI58 range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the Hengstler ICURO RI58?
Yes. Our engineers can propose an equivalent built around your load, speed and environment. An engineer confirms the fit against your application before recommending anything.
What is quadrature output on an incremental encoder?
Quadrature output provides two channels, A and B, offset by 90 electrical degrees. Comparing which leads gives direction, and counting edges on both gives four times the line count in resolution. An index pulse marks a reference position for homing.
What is the difference between TTL and HTL outputs?
TTL outputs use a 5 V differential signal, which suits high frequencies and is commonly used with line drivers. HTL outputs use a higher voltage swing, typically matched to a 10 to 30 V supply, which improves noise immunity on long cables. Match the output type to the drive or controller input.
Further reading: Absolute vs incremental encoders · How to select an encoder · Encoders and feedback
Other optical incremental encoder series
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Tell us about your project and how you use the Hengstler ICURO RI58: the load, speed, duty and environment. An experienced engineer will review it and reply, normally within one working day.
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