The AR25M is a high-resolution absolute optical encoder designed for precision motion control, robotics, and servo systems. Its bearingless, open-type hollow shaft design eliminates mechanical wear and reduces maintenance. As a result, it delivers reliable, long-term performance in demanding industrial applications. The encoder uses dual optical reflectance sensors positioned 180° apart to compensate for shaft runout and minimize mechanical errors, improving overall measurement accuracy.
The encoder provides single-turn absolute position feedback with up to 20-bit resolution and ±100 arc-second accuracy. It supports BiSS-C and SSI interfaces for absolute feedback, as well as TTL incremental outputs for speed and position control. In addition, it offers binary and Gray code output options to meet different system requirements.
The AR25M supports shaft speeds up to 20,000 RPM and communicates at clock frequencies up to 20 MHz. It operates from a 5 VDC supply and delivers calculation times of less than 2 µs for fast, responsive motion control. Multiple cable lengths and connector options simplify installation and integration into OEM equipment.
The encoder operates in temperatures from –40°C to +70°C and withstands 100 m/s² vibration, 400 m/s² shock, and humidity levels up to 98% non-condensing. These features make the AR25M an excellent choice for servo motors, robotics, semiconductor equipment, machine tools, precision automation, and other high-speed positioning applications where compact size and accurate absolute feedback are essential.
Mechanical data
| Maximum shaft speed | 20 000 rpm |
| Protection (IEC 529) | IP00 |
| Maximum weight without cable | 0.01 kg |
| Operating temperature | -40…+70°C |
| Storage temperature | -40…+100°C |
| Maximum humidity (non-condensing) | 98% |
| Permissible vibration (55 to 2000 Hz) | ≤ 100 m/s² |
| Permissible shock (11 ms) | ≤ 400 m/s² |