MR302-2 Controller



OEM Controller for MR30X Series Incremental Encoders

The MR302-2 PCB Controller enables Original Equipment Manufacturers (OEMs) to compactly and cost effectively integrate MR30X series fiber optic position sensors within their own equipment designs.

In operation, the MR302-2 Controller sends two optical wavelength signals to a remote MR30X series Sensor. The encoder then modulates each optical beam based on the direction with a leading or lagging phase shift. The return optical signals are split into two separate beams and converted back into electrical signals by two photodiodes whose outputs are amplified by two gain-controlled amplifiers. A microprocessor supervises the amplitude of the optical signals and constantly adjusts the signal to provide a stable quadrature output.

The system has built-in diagnostics and can signal any anomaly occurring during sensor operation.



Electrical Interface
Connector 16-pin ribbon cable receptacle, 3M N2516-5002-RB

Recommended mating plug, 3M 89116-0103

Quadrature Outputs A+/A-/B+/B- RS422 line driver outputs, 100 kHz maximum bandwidth
Discrete Signals ZERO Input, STATUS out, 5V logic
Serial Interface Modbus RTU or RS422/485 compatible, User settable baudrate: 9,600 to 115,200

Byte format: 1 Start Bit, 8 Data Bits, 1 Stop Bit, No Parity

Power Supply +5 VDC, 55mA typical, 100mA maximum

Recommend 100mA power supply

Optical Interface
Connector LC Duplex
Fiber Type Duplex 62.5/125μm, Graded Index Fiber, 0.275 NA, Type OM-1
System Loss Budget 10dB
Maximum Distance Up to 1600 meters (5250 ft) with MR30X series Sensor
Environmental Attributes
Temperature/Humidity -5°C to +55°C (23°F to +131°F), 0-95% RH, Non-Condensing
Ingress Protection IP30, Keep free from contaminants
Physical Attributes
Dimensions 98.9 x 50.8 x 12.7 mm (3.5 x 2.0 x 0.50 inches)

plus ≈61.0 mm (2.40 inch) connector clearance

Mounting 4x #2-56 or M2.5 screws, Mounting pattern 3.10 x 1.60 inches
Weight 25g (0.9 oz)

Specifications subject to change without notice

Ordering Information

Linear Encoder
MR303-B400CXX, Consult MR303 data sheet for product information
Rotary Encoder
MR304-E03CXX, Consult MR304 data sheet for detailed producct information


  • Medical
  • MRI
  • Robotics
  • Industrial


  • Compact PCB form factor for ease of OEM system integration
  • Supports all MR30X series rotary and linear sensors
  • Operates from 5 VDC
  • A/A’/B/B’ RS422 line driver quadrature outputs
  • Modbus RTU/RS485/RS422 compatible serial interface
  • RS232 or USB intefacing available with optional converter
  • Feature rich Modbus communications protocol
  • LC Duplex multimode optical link operates up to 1600 meters


Call +1-805-389-6600 or email

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