access guarding

Multiple light beam safety devices MLD 300 (type 2/PL c) and MLD 500 (type 4/PL e) safeguard accesses to dangerous areas and are used, e.g., on machine tools or in intralogistics. They are characterized by a number of clever solutions, such as the economical transceiver systems, the integrated laser alignment aid and integrated muting function as well as configuration by means of wiring.

This system consists of an active transceiver (transmitter / receiver in one housing) and a passive deflecting mirror without electrical connection.
This offers economical solutions with low installation effort.
  • 2- and 3-beam systems available
  • Range from 0.5 to 8 m
This system consists of separate transmitter and receiver (and deflecting mirrors as necessary) for applications with large operating ranges.
  • 2-, 3- and 4-beam systems available
  • Operating range MLD…-R /-T: 0.5 to 50 m
  • Operating range MLD…-xR /-xT: 20 to 70 m


  • Integrated alignment aid
    Fast and easy installation, particularly over long distances and with multiple-side guarding with deflecting mirrors
  • Multicolor indicator lights
    For displaying OSSD and error states as well as the muting status


  • Integrated muting functions
    Time- and sequence-controlled muting functions with 2- or 4-muting sensors already integrated in the sensor. Can be configured via pin assignments.
  • Pre-mounted sets
    For fast and easy installation, pre-mounted sensors and reflectors and even complete sets including device columns and wiring are available.
  • AS-i Safety interface
    Direct connection to AS-i bus without additional coupling module
  • Muting in the AS-i network
    The ASM-m safety monitor controls the muting sequence
One-sided access guardingMulti-sided access guardingAccess guarding with muting function
If there are dangerous areas on machines and systems, access to these areas must be safeguarded. Because material must also be regularly and easily fed in and discharged, hard guards in the form of fences with access doors are not practical here. Depending on the application, access should be possible from one or more sides.

The MLD 300/500 multiple light beam safety devices offer economical solutions for access guarding with optical safety sensors. The transceiver models with an operating range of up to 8 m are especially easy to install. For wide-area guarding, transmitter/receiver models are available with a range of up to 70 m. Multi-side guarding is realized with mirror columns. The integrated laser alignment aid ensures simple and time-saving alignment here.
On conveyor lines, access to dangerous areas must be safeguarded. For material transport, temporary bridging of the protective function that is triggered only by the transport material is necessary. The solutions should be simple and possible to install with little effort.

The 330/335 and 530/535 versions of the multiple light beam safety devices have muting functions for bridging the protective field already integrated in the sensor. The economical 2- and 3-beam transceiver systems with operating range of up to 8 m are especially easy to install. For error-free configuration and fast device exchange, all MLDs are configured via wiring.