Light barriers
What are light barriers?
Light curtains type 4 are used for access detection of people to machines and installations.
During an intrusion, the infrared rays between the transmitter and the receiver get broken. This will cause safety output signals to be generated which will stop the dangerous motion of the machine.
TüV certified
Pld / Ple according to EN/ISO 13849-1
Type 4 light curtains
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MLG type 4 safety light curtains
The Mechan Controls MLG is a cost-effective type 4 safety light curtain available in three different resolutions suitable for finger, hand and body detection.
The MLG light curtain is suitable for use in SIL3 (EN / IEC 62061), Category 4 (EN 954-1) and PLe (EN / ISO 13849-1) applications.
- Type 4 safety light curtain
- Available in different resolutions and multi-beam
- Cost-effective
- Available in different detection heights from 200mm to 1800mm
- Voorzien van een stekkeraansluiting
- Supplied with mounting brackets
- Detection distance from 0,5m to 15m
- Use in combination with our GM1 safety controller
MLG-14 light curtain
The Mechan Controls MLG-14 is a type 4 light curtain and therefore suitable for use in SIL 3, Cat. 4 and PLe machine safety applications.
With a resolution of 14mm this light curtain is suitable for finger, hand and body protection. The detection range is 0.5m to 6m. The MLG-14 is available with a detection height of 200, 400, 600, 800, 1000 and 1200mm.
MLG-30 licht curtain
The MLG-30 by Mechan Controls is a light curtain type 4 and therefore suitable for use in SIL 3, Cat. 4 and PLe machine safety applications.
With a resolution of 30mm, this light screen is suitable for hand detection and body detection. The detection distance is 0.5m to 15m. The MLG-30 is available with a detection height of 200, 400, 600, 800, 1000 and 1200mm.
MLG-70 light curtain
The Mechan Controls MLG-70 is a type 4 light curtain and therefore suitable for use in SIL 3, Cat. 4 and PLe machine safety applications.
With a resolution of 70mm, this light screen is only suitable for body detection. The detection distance is 0.5m to 15m. The MLG-70 is available with a detection height of 200, 400, 600, 800, 1000 and 1200mm.
Multi-beam light curtain
Multi-beam safety curtains can only be used for walk-in protection. The MLG multi-beam light curtains are a cheap alternative and are type 4 light curtains and therefore suitable for SIL 3, Cat. 4 and PLe applications.
The number of beams depends on the detection height. The MLG multi-beam is available with 2, 3 or 4 beams. The detection distance for all variants is 0.5m to 30m.
GM1 controller
The Mechan Controls GM1 / GSM is a safety controller for controlling one or more MLG light curtains within a area.
To control multiple light curtains, the GM1 master controller can be expanded with a GSM module for each additional light curtain.
Which light curtain for which application?
Walk-in protection
Multiple beams (2,3,4) Article: MLG-2/3/4
Body protection
Beam distance: 40-70mm Article: MLG-2/3/4
Hand detection
Beam distance: 20-40mm Article: MLG-30
Finger detection
Beam distance: 14mm Article: MLG-14
Frequently asked questions about light curtains
A safety light curtain is an optoelectronic protective device consisting of a transmitter and receiver that create a protective field using infrared light beams. When a person or body part interrupts the field, the safety outputs change state so the machine’s safety-related control system can initiate the required safe response.
Light curtains are suitable where frequent or unobstructed access to a hazardous area is required without using a physical guard at that opening. Typical applications include packaging machines, presses, robotic systems, assembly lines, and conveyor systems. Their suitability must be determined through the machine risk assessment.
Resolution determines the smallest object or body part the protective device is designed to detect. For the Mechan Controls MLG range offered by Unique Safety Products:
14 mm – Finger detection
30 mm – Hand and body detection
70 mm – Body detection
2, 3 or 4 beams – Walk-in/access protection
A light curtain must be positioned at a sufficient minimum distance from the hazardous zone so the dangerous machine movement can stop before a person reaches the hazard.
The calculation considers factors including the machine stopping time, light curtain response time, approach speed, resolution, and type of approach. EN ISO 13855 provides requirements for positioning safeguards with respect to the approach of the human body.
Muting is the automatic and temporary suspension of the protective function under defined conditions, typically to allow material to enter or leave a safeguarded area without stopping the machine.
For example, muting sensors can recognize the defined sequence associated with a pallet moving through a conveyor opening while maintaining detection requirements for personnel. Muting design and implementation require careful safety assessment.
Correct installation requires more than mounting the transmitter and receiver. Important considerations include minimum safety distance, protective field height, alignment, possible reach-over or reach-under access, reflective surfaces, interference from other optical devices, and the possibility of a person remaining undetected inside the safeguarded area.
For EU/EEA machine-safety applications, key standards include EN IEC 61496-1 for electro-sensitive protective equipment and EN ISO 13855 for positioning safeguards based on approach speeds. The overall safety function may also be designed and evaluated according to EN ISO 13849-1 or EN IEC 62061.
Unique Safety Products specifies its Mechan Controls MLG as a Type 4 safety light curtain and states suitability for applications up to PL e according to EN ISO 13849-1 and SIL 3 according to EN IEC 62061. The required performance level or SIL must still be established from the machine’s risk assessment and safety-function design.
