Ø38mm absolute modular encoder

AR38

The AR38 modular optical encoder is a compact and precise solution designed for integration into rotary systems where space, performance, and flexibility are critical. The encoder features a lightweight PCB-based stator and a compact rotor with precision circular scale, enabling seamless integration into motors, robotic joints, and automation equipment.

• Modular lightweight design
• Zero set and direction control
• Dual LED feedback
• Enhanced by OrbiSyncTM dual sensor technology

Mechanical data

Stator
Material FR4
Outside diameter (OD) 38 mm
Inside diameter (ID) 14 mm
Weight (without cable) < 6 g
PCB fabrication per IPC-A-600 Class 3
PCB assembly per IPC-A-610 Class 3
Soldering process per J-STD-001 Class 3
Conformal coating (top side el. components) per IPC-CC-830
Rotor
Material Stainless steel hub + chromium circular scale on glass disc
Outside diameter (OD) 30 mm
Inside diameter (ID) D H7 mm
Mass moment of inertia < 1.5 x 10-6 kgm2
Weight < 10 g
Max. mechanical speed 5000 RPM
Installation tolerances (between rotor and stator)
Nominal air gap between optical sensor and glass disc (1.75 ± 0.5 mm)
Matting dimension (between mounting surfaces) 4.65 ± 0.3 mm
Tangential displacement of the stator ± 0.3 mm
Radial displacement of the stator ± 0.3 mm
Permissible radial runout of the customer shaft < 0.1 mm
Environmental data
Operating temperature  -40oC – 100oC
Storage temperature  -40oC – 100oC
Relative humidity 98 % (non condensing)
Permissible vibration (10 to 2000 Hz) 20G sweep (EN 60068-2-6:2008)
Permissible shock (6 ms) 100G saw-tooth (EN 60068-2-27:2009)
Protection IP00
Environmental compliance RoHs

Electrical data

Electrical interface SSI / BISS
Output code Binary
Resolution Up to 22 bit
Accuracy* ± 20″
Repeatability 2.5″
Supply voltage  + 5V ± 10%
Current consumption (without load) < 200 mA

*the overall system accuracy depends on the mechanical mounting conditions, including stator-to-rotor alignment, axial and radial positioning, and rotor eccentricity. Under recommended installation practices, typical system accuracy reaches the specified value.
Note: Deviation from recommended mounting tolerances may lead to increased measurement error.

Zero position setting function
To enhance flexibility in system integration, the encoder includes a dedicated Zero Set input wire, allowing users to define the absolute zero position according to the specific requirements of their application. By activating this input at any desired mechanical position, the encoder reassigns that position as the new absolute zero, ensuring seamless alignment with the machine’s coordinate system. This feature eliminates the need for mechanical repositioning or external software tools, streamlining both installation and commissioning processes. This functionality is especially useful in applications where mechanical reference points vary between builds, or where field recalibration is needed after maintenance or replacement.

Counting direction configuration
To support flexible integration with various mechanical systems, the encoder features an additional input wire that allows users to configure the absolute position counting direction. By toggling this input, the encoder can be set to count position values in either a clockwise (CW) or
counterclockwise (CCW) direction — ensuring compatibility with the specific rotational logic of the application. This feature enables quick adaptation without requiring mechanical changes or firmware reconfiguration, simplifying installation and improving alignment with system control schemes.

Orbisync™ Technology
Orbisync™ is a next-generation optical encoder platform developed for high-precision absolute rotary sensing. Leveraging a dual-sensor architecture with built-in intelligence, it continuously calibrates itself to maintain accuracy over time and varying conditions. Advanced onboard processing ensures clean, reliable position data, even in dynamic environments. Its modular design supports both compact open-frame and fully housed configurations, making it a versatile solution for modern motion systems.

Special Features
Precizika Metrology offers exceptional flexibility in our design and manufacturing processes, allowing us to create tailor-made encoders to meet specific customer needs. We can also modify our standard encoders to accommodate different rotor diameters or designs, special wiring configurations, different mechanical interfaces, etc. Additionally, we can incorporate other custom features, such as specialized connectors, couplings, and various accessories, to ensure seamless integration into your application. Furthermore, we can adapt the design and conduct testing for various environmental conditions, including higher ingress protection levels, extended temperature ranges, and resistance to intensive mechanical vibrations or shock.

More information available in the full datasheet.

Accessories

Downloads

Order code

AR38 – X1 – X2 – X3 – X4 – X5 – X6 – X7-X8
Output signals interface (X1) Bit number (X2) Rotor inner diameter “D” (X3) Connection type (X4) Cable assembly (X5) Cable length (X6) Connector (X7) Special feature (X8)
S – SSI
B – BISS
B01 – 1 bit
B22 – 22 bits
06 – ⌀6 mm
08 – ⌀8 mm
10 – ⌀10 mm
C – connector based
D – direct wire soldering
W – empty pads soldering (ready for customer soldering)
RI – Ribbon cable
RO – Round cable
W – Without cable
00 – use if no cable assembly is selected (W)
10 – 100 mm
25 – 250 mm
100 – 1000 mm
W – without connector
IDC – 8-pins connector (only for ribbon cable)
D9 – DSUB-9, 9 pins
C0 – no special feature

Order form

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