Light Curtains are made up of arrayed emitting and receiving elements. The international standard IEC 61596 specifies requirements for the design, construction, and testing of two levels or "types" of light curtains or screens. Type 2 and Type 4 describe different requirements to ensure that the appropriate safety related performance is achieved.
Type 4 achieves high levels of fault tolerance through redundancy and monitoring. The control reliable Type 4 is intended for high risk applications that can result in severe injury or death.
It only has one microprocessor, Type 2 uses fault exclusion as its main method to ensure the integrity of the safety function. Type 2 light screens have a larger field-of-view or Effective Aperture Angle (EAA), Type 2 light screens are...