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Related Products

RF20 Ultra-Compact Reflective Optical Encoder Module | 20mm 500~8000 CPR | EPOCH| 20mm 500~8000 CPR | EPOCH

[RF20 SERIES] standard 20mm ultra-compact reflective optical encoder module

RF20 Reflective Optical Encoder Module — Ultra-Compact 20mm, 3-Channel 500~8000 CPR Differential Output, for DC Motor & Servo Motor Feedback

Name: RF20 Ultra-Compact Reflective Optical Encoder Module
Brand: EPOCH
Availability: InStock

RF20 series reflective encoder with PCBA and integrated housing design, with code disc, can output three channels of differential signals ranging from 500~4096CPR. Z signal can be selected from 90°, 180° and 360°, standard is 90°. Suitable for small size DC motor, stepping motor and servo motor.

Quick Select: Mechanical Drawings Features Tech Specs Waveform Pin Definition Ordering Guide FAQ

RF20 Mechanical Dimension Drawing — 20mm Ultra-Compact Reflective Optical Encoder Module Footprint (13.0×20.2 mm)

RF20 Series — Mechanical Dimension Drawing

RF20 Mechanical Dimension Drawing

RF20 Series Mechanical Dimension Drawing

Ultra-compact 20mm footprint. 13.0×20.2 mm overall dimensions. Unit: mm.

Motor End Face & Shaft Dimensions — RF20 Reflective Optical Encoder Module

RF20 Dimensions Of Motor End Face and outgoing shaft length

Motor shaft axial play ≤ 0.1 mm. Unit: mm.

[FEATURES] RF20 Series Reflective Optical Encoder Module — Key Features & Description

•

Type: Ultra-compact 20mm reflective optical encoder module with integrated housing

•

Resolution: 500 ~ 8,000 CPR (3-channel differential)

•

Output: A, A/, B, B/, Z, Z/ — Differential type

•

Z Signal: Selectable 90°, 180°, or 360° (standard 90°)

•

Supply: 3V ~ 5V DC

•

Max Speed: 11,000 RPM

•

Temp Range: -40°C to +85°C

•

Design: PCBA integrated housing with code disc

•

Form Factor: Ultra-compact 20mm footprint (13.0×20.2 mm)

•

Plug: SHR-09V-S (9-pin)

RF20 Technical Specifications — 500~8000 CPR 3-Channel Differential Reflective Encoder Module

Parameter	Specification
Technology	Reflective optical encoding with PCBA and code disc
Output Signals	A, A/, B, B/, Z, Z/ (differential)
Resolution Range	500 ~ 8,000 CPR
Supply Voltage	3V ~ 5V DC
Max Mechanical Speed	11,000 RPM
Operating Temperature	-40°C ~ +85°C
Shaft Diameter Options	2mm, 3mm, 4mm, 5mm, 6mm, 1/8in, 5/32in, 3/16in, 1/4in
Z Signal Options	Selectable 90°, 180°, 360° (standard 90°)
Motor Shaft Axial Play	≤ 0.1 mm
Recommended Plug	SHR-09V-S
Application	DC motors, stepping motors, servo motors

Output Waveform Diagram — RF20 Series 3-Channel Differential Timing

RF20 Series Output Waveform Diagram

RF20 Series Output Waveform Diagram

Three-channel differential output (A, A/, B, B/, Z, Z/) with 90° electrical phase shift between A and B. Z signal indicates index position (selectable 90°, 180°, 360°).

Pin Definition — RF20 Series (9-Pin, SHR-09V-S Plug)

Two identification methods available (A and B). The ID Code in the ordering code determines which pin arrangement is used — Method A places Z/Z/ before B/B/ (Pin 5-6), while Method B places B/B/ before Z/Z/ (Pin 5-6).

RF20 Pin Connection Diagram

Line number

Line number 1P24-Plug Recommended Model: SHR-09V-S

Pin / Method	1	2	3	4	5	6	7	8	9
Method A	Vcc	Gnd	A	A/	Z	Z/	N.C.	B	B/
Method B	Vcc	Gnd	A	A/	B	B/	Z	Z/	N.C.

Direction: All signal names listed are viewed from the encoder module connector side. Vcc = Power Supply (3-5V DC), Gnd = Ground, A/B = Channel Outputs, A//B/ = Complementary Outputs, Z = Index Signal, Z/ = Complementary Index, N.C. = Not Connected.

Ordering Information / Part Number — RF20 Series Reflective Optical Encoder Module

Code Structure: RF20 [CPR Code] [Shaft Dia. Code] [ID Code]

R

→

F

→

2

→

0

→

CPR Code

→

Shaft Dia. Code

→

ID Code

Series Prefix

e.g. A=500, B=1000

e.g. 01=2mm, 06=1/4in

A or B
Pin Method

CPR Code	A	I	B	J	T	U	N	R	8K
CPR	500	512	1,000	1,024	2,000	2,048	4,000	4,096	8,000

Shaft Dia. Code	01	02	03	04	05	06
Diameter	2 mm	3 mm	1/8 in	5/32 in	3/16 in	1/4 in

ID Code	A	B
Pin Definition Method	Method A (Z before B)	Method B (B before Z)

Example Ordering Code:

RF20-A-01-A

= RF20 Series · A=500 CPR · 01=2mm shaft · A=Method A Pinout

Module Printing / Label — RF20 Reflective Optical Encoder Module

RF20 Module Printing / Label

RF20 Model Print

Module printing includes model code, CPR rating, shaft diameter, and ID code as per ordering code format.

Technical FAQs — RF20 Series Reflective Optical Encoder Module

Q: What output signals does the RF20 ultra-compact reflective optical encoder module provide?

A: The RF20 ultra-compact reflective optical encoder module provides 3-channel differential output signals: A, A/, B, B/, Z, Z/. The Z (index) signal is selectable at 90°, 180°, or 360° (standard 90°).

Q: How is the RF20 20mm reflective optical encoder module constructed?

A: The RF20 reflective optical encoder module features a PCBA and integrated housing design with a code disc, making it a compact 20mm reflective unit suitable for direct motor mounting without additional bearings.

Q: What shaft diameters are available for the RF20 20mm reflective optical encoder module?

A: The RF20 reflective optical encoder module supports 9 shaft diameter options: 2mm, 3mm, 4mm, 5mm, 6mm, 1/8in, 5/32in, 3/16in, and 1/4in, selectable via the ordering code.

Q: What motor types are compatible with the RF20 3-channel differential reflective encoder module?

A: The RF20 reflective optical encoder module is designed for small DC motor, stepping motor, and servo motor feedback applications requiring precision 3-channel differential position sensing.

[CROSS-REFERENCE] Need a Standard 28mm Form Factor?

RF28 Reflective Optical Encoder Module — Standard 28mm (Ø28.9 mm) form factor with additional shaft diameter options (4mm, 5mm, 6mm) and extra resolution codes including W=2500 and Z=5000 CPR for higher precision applications. Shares the same 3-channel differential output and selectable Z signal as the RF20 reflective encoder module.

B2B Global RF20 Encoder Sourcing

Request a Quote

Need custom resolution, shaft diameter, or bulk pricing for the RF20 ultra-compact reflective optical encoder module? Contact our sales team.

Request Direct Sourcing Evaluation →

Sales: liya@epoch-electronic.com

Legal Disclaimer: All manufacturer names and trademarks referenced are for cross-compatibility reference only. EPOCH is an independent manufacturer with no affiliation to OEM brands.