The Safety Light Curtain is an optoelectronic device that is used to safeguard personnel in the vicinity of moving machinery with the potential to cause harm such as hydraulic presses, filter presses, packaging equipment and winders. The Safety Light Curtain can be used as an alternative to mechanical barriers and other forms of traditional machine guarding. It is a safety device that can emergently stop an operator when people or objects are detected at the pinch point. Typically, the Safety Light Curtain is connected to a safety relay which will remove motive power from the hazard in the event when an object is detected.

Usually, a safety light curtain consists of a transmitter and a receiver. The Safety Light Curtain controls the infrared emitter (projected side) and receptor (receiving side) from the RL78/G11 MCU via an analog multiplexer. The port outputs a negative-positive-negative (NPN) signal and controls external relay. If the settings are normal and no object is detected in the protected area, an LED will light up to indicate safety. The RL78/G11 MCU is suitable for products with sensor application technology.

Disclaimer: THIS MATERIAL IS PROVIDED “AS-IS” FOR EVALUATION PURPOSES ONLY. RENESAS ELECTRONICS CORPORATION AND ITS SUBSIDIARIES (collectively, “Renesas”) DISCLAIM ALL WARRANTIES, INCLUDING WITHOUT LIMITATION, FITNESS FOR A PARTICULAR PURPOSE AND MERCHANTABILITY. Renesas provides evaluation platforms and design proposals to help our customers to develop products. However, factors beyond Renesas' control, including without limitation, component variations, temperature changes and PCB layout, could significantly affect the product performance. It is the user’s responsibility to verify the actual circuit performance.


  • Power Supply: +24V DC
  • Protection height: 140mm
  • Detecting distance: 1~2000mm (adjustable by configuration parameters)
  • Beams: 8
  • Gap of optical axis: 20mm
  • Resolution: 15mm
  • Response time: 10ms
  • Output type: NPN

Documentation & Downloads

Title Other Languages Type Format File Size Date
RL78/G11 Safety Light Curtain Batch Download Sample Code ZIP 2.84 MB
Renesas RL78 Family Microcontrollers Brochure 日本語 Flyer PDF 5.89 MB