Fiber Optic Rotary and Linear Encoders

First, what type of encoder does your application require?

  • Absolute encoders (also called  position sensors) are used where monitoring absolute position and high precision are required. Their signature output is a digital value of absolute position. Even if an absolute encoder loses power, the system will always report it current true position upon start-up.
  • Incremental encoders are used where speed and relative position need to be monitored, and typically offer lesser resolution than an absolute encoder system. Their signature outputs are A/B quadrature pulses. The user’s motion control system tracks these pulses (phasing determines direction) to monitor relative position from initial Home setting. The same system measures the time between pulses to track speed. If  the system loses power,  all position and speed information is typically lost.

MR340 Series

Fiber Optic Incremental Encoders

MR340 series is Micronor’s 3rd Generation Fiber Optical Incremental Encoders – comprising both rotary and linear models. Fiber optic incremental encoders are typically used to sense the motion and speed of a motor shaft or linear actuator where conventional electronics-based encoders and resolvers are inadequate. Typically the user’s control system is looking for A/B quadrature signals for which electro-magnetic interference and noise causes system errors.

Micronor Fiber Optic Incremental Encoders are based on an all-optical passive sensor design which optically connects to a remote controller via a standard duplex OM1 62.5/125 multimode fiber optic link spanning distances up to 2000 meters. The Controllers offer much more interface capability besides A/B quadrature outputs. The additional built-in analog (4-20mA, ±10V) and digital interfaces (RS485, USB, Modbus RTU) can also be user-programmed to output speed or position status.

MR330 and MR430 Series

Fiber Optic Absolute Encoders

The MR330 and MR430 series Fiber Optic Position Sensors (aka Absolute Encoders) measures absolute angular position from 0° to 360° and can track up to 4096 turns.

  • The MR330 uses 62.5/125 Glass Optical Fiber (GOF) and provides 13/14 bit (0.026°) single-turn resolution and 12-bit multiturn tracking. The system can operate at full accuracy at speeds > 2500 rpm and distances > 300 meters. This sensor system uses a novel optical spectral imprint technique. The sensors is available in both Industrial and MRI Safe models. The DIN Controller provides multiple built-in interfaces: SSI, USB, RS485/Modbus RTU, Digital Set Points and Analog Outputs.
  • The MR430 series is based on Plastic Optical Fiber (POF) technology that achieves a new sweet spot for size, cost, and performance, for the many challenging applications and potential designs that could not formerly justify using fiber optic sensor technology. In size, the MR430 sensor features a miniature Size 11 (Ø1.1”) form factor suitable for the smallest robotic or actuator mechanism. In performance, the encoder offers 25-bit resolution (13-bit Single Turn + 12-bit Multi-turn) with an update rate of 850µs and ability to operate interference-free over distances up to 30 meters (100 ft). In cost, the use of inexpensive POF cabling optics achieves a price point less than prior glass fiber-based absolute encoders. The sensor’s non-metallic construction offers both magnetic immunity and transparency for MRI applications as well as superior corrosion resistance for the harshest industrial environment.