Optical absolute encoder
HEIDENHAIN RCN 2001 / RCN 5001 angle encoders
Absolute angle encoders with integral bearing and hollow through-shaft for rotary tables and swivel heads.
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- 2Performance
- 3Environment
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- 5Your spec
What are you specifying?
Select everything you need. A motor, drive and gearbox can be specified together as one axis.
Key specifications
| Speed (max) | 3,000 rpm |
|---|---|
| Bore (max) | 35 mm |
| Resolution (max) | 28 bit |
| Accuracy | system accuracy ±2" (RCN 2001) / ±4" (RCN 5001) |
| Interface | EnDat 2.2, Fanuc αi, Mitsubishi high speed |
Summarised in our own words from DR. JOHANNES HEIDENHAIN GmbH's published data; series maxima, individual models vary. Last checked 2026-10-29. Source 1
Notes on this data
26 bit / 28 bit; hollow shaft 20 / 35 mm; 3000 rpm with purely serial interface. Paired values assumed in series order. Page does not say whether these succeed the older RCN 2000/5000 names.
Specify Motion is not affiliated with DR. JOHANNES HEIDENHAIN GmbH. HEIDENHAIN and RCN 2001 / RCN 5001 angle encoders are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
HEIDENHAIN RCN 2001 / RCN 5001 angle encoders replacement and alternative options
Use these supply-network options as a starting point for an engineering check. We can also help source the original HEIDENHAIN part. Published series figures do not establish an exact-model or drop-in replacement: confirm ratings, fit, interfaces and approvals for your application.
Multi-turn absolute hollow-shaft capacitive encoder that holds position through power loss, so no re-homing.
| Published maximum | RCN 2001 / RCN 5001 angle encoders | VLM |
|---|---|---|
| Resolution | 28 bit | 32 bit meets or exceeds |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
Typical applications
What an optical absolute encoder is
An optical absolute encoder reads a unique code pattern on a disc or scale, so every position has its own digital value and position is known immediately at power-up. Single-turn encoders give position within one revolution; multi-turn encoders also count revolutions using gears or electronic counters. Position is sent over a serial interface such as SSI or BiSS, a manufacturer-specific protocol, or a fieldbus. Optical scanning gives high resolution, typically 17 bits per revolution or more in servo encoders, and good accuracy.
When engineers choose an optical absolute encoder
Choose an optical absolute encoder where knowing position at power-up matters, such as robots, machine tools, multi-axis machines and axes that cannot be homed safely. It removes homing routines and supports safety functions. The trade-offs are cost, interface compatibility and contamination sensitivity. Battery-backed multi-turn types need battery maintenance; gear or energy-harvesting types avoid that. In very dirty environments, magnetic or inductive absolute encoders may suit better.
How to specify the HEIDENHAIN RCN 2001 / RCN 5001 angle encoders
Send these with your enquiry and an engineer can confirm the right RCN 2001 / RCN 5001 angle encoders variant or an equivalent:
- Single-turn resolution (bits)
- Multi-turn range (revolutions)
- Interface: SSI, BiSS, proprietary serial or fieldbus
- Accuracy (arcsec)
- Shaft or hollow shaft size (mm)
- Speed (rpm)
- Environment and safety rating
Common mistakes to avoid
- Choosing an interface the drive does not support
- Forgetting battery maintenance on battery-backed multi-turn types
- Confusing resolution with accuracy
- Ignoring cable length limits for serial interfaces
HEIDENHAIN RCN 2001 / RCN 5001 angle encoders: frequently asked questions
Can you help replace HEIDENHAIN RCN 2001 / RCN 5001 angle encoders or source the original?
Send the full model code, quantity and required date. Our engineers can check original-part availability and assess suitable alternatives, including supply-network options where appropriate. We confirm compatibility and any changes needed before recommending a replacement.
What is the HEIDENHAIN RCN 2001 / RCN 5001 angle encoders?
Absolute angle encoders with integral bearing and hollow through-shaft for rotary tables and swivel heads. Published series figures include speed 3,000 rpm, bore 35 mm, resolution 28 bit. It is made by DR. JOHANNES HEIDENHAIN GmbH; Specify Motion can help source it or propose an equivalent.
Who makes the HEIDENHAIN RCN 2001 / RCN 5001 angle encoders?
The HEIDENHAIN RCN 2001 / RCN 5001 angle encoders is made by HEIDENHAIN (DR. JOHANNES HEIDENHAIN GmbH) and is listed here for engineers comparing options. Specify Motion is not affiliated with DR. JOHANNES HEIDENHAIN GmbH; brand names are used only to identify the product.
What is the speed of the HEIDENHAIN RCN 2001 / RCN 5001 angle encoders?
The published series maximum speed is 3,000 rpm. Individual models and sizes in the RCN 2001 / RCN 5001 angle encoders 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 HEIDENHAIN RCN 2001 / RCN 5001 angle encoders?
We can assess suitable replacement options. On published figures, Netzer Precision VLM is options to assess from our supply network. An engineer confirms the fit against your application before recommending anything.
What is the difference between single-turn and multi-turn absolute encoders?
A single-turn absolute encoder knows its angle within one revolution. A multi-turn absolute encoder also counts complete revolutions, so it knows total position over many turns even after power loss. Multi-turn encoders avoid homing on axes driven through screws or gears.
Which interface should an absolute encoder use?
Use the interface supported by the drive or controller. SSI is simple and widely supported, BiSS-C is an open bidirectional protocol, and several manufacturer-specific protocols are common on machine tools and servo drives. Fieldbus encoders suit PLC networks. Check cable lengths and update rates for the control loop.
Further reading: Absolute vs incremental encoders · How to select an encoder · Encoders and feedback
Other optical absolute encoder series
Engineer support
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Tell us how you use the HEIDENHAIN RCN 2001 / RCN 5001 angle encoders: the load, speed, duty and environment. Our engineers will confirm whether it is still the right part, find it for you, or propose an alternative that fits better.
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Prefer to configure it? Use the spec builder.
How it works
From enquiry to delivery
Send a part number or describe the application. Our engineers take it from there: the right product, a clear quotation, and delivery and support arranged.
- 01Tell us what you needSend a part number, or configure the application, quantities and timing.
- 02An engineer reviews itWe check the specification and find the original part, a checked equivalent or a complete axis.
- 03Receive your quotationProducts, pricing, lead time and compatibility notes in one reply.
- 04Order and deliveryWhen you are happy, the order is placed and delivery and after-sales support are arranged.