Machine Safety - Light Curtains

Part Number	Description / PDF	Quantity
LS4EL Banner Engineering	LS4 SERIES: LIGHT SCREEN EMITTER	2
SLLP23-1540 Banner Engineering	EZ-SCREEN LS, PAIRRESOLUTION	2
SLLCE23-1260P8 Banner Engineering	EZ-SCREEN LS CASCADE, EMITTER<BR	2
SLSK14-900Q88-1RE15 Banner Engineering	SLSK14-900Q88-1RE15 EZS KIT 14MM	0
SLPP25-1390P88 Banner Engineering	SLPP25-1390P88 EZ-SCREEN LOW PRO	0

Machine Safety - Light Curtains

1. Overview

Light curtains are photoelectric sensing devices used to protect personnel and equipment in industrial automation systems. They consist of transmitters and receivers that project and detect light beams to create a protective field. When an object interrupts the beam, the system triggers a safety response (e.g., stopping machinery). These devices are critical in modern manufacturing for compliance with safety standards (e.g., ISO 13849-1) and reducing workplace injuries.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Opposed Mode	Separate transmitter and receiver units	Large machinery (e.g., stamping presses)
Reflective Mode	Single unit with reflector; cost-effective	Conveyor systems
Multi-beam	Multiple parallel beams for high-resolution detection	Robot workcells
Single-beam	Simple on/off detection	Entryway guarding

3. Structure and Components

Typical components include:

Transmitter: Emits modulated infrared or visible light
Receiver: Detects beams using photodiodes
Controller: Processes signals and triggers safety outputs
Enclosure: IP-rated housing for environmental protection

4. Key Technical Specifications

Parameter	Description	Importance
Detection Distance	0.3-30 meters	Determines application range
Resolution	10-50 mm	Object size detection capability
Response Time	2-20 ms	Speed of safety reaction
Protection Class	IP65-IP69K	Environmental durability
Safety Category	Cat. 2/PLc to Cat. 4/PLd	Compliance with safety standards

5. Application Fields

Key industries and equipment:

Automotive manufacturing (robotic arms)
Metalworking machinery (lathes, presses)
Food processing equipment
Packaging machines
Assembly lines

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Features
SICK AG	OT/OS32C series	Up to 30m detection range, IP69K
Banner Engineering	QS30/TL70	High-temperature resistance, wireless options
Omron	F3SG-RA series	Multi-beam with self-diagnosis
Keyence	CV-L3 series	High-speed detection for robotics

7. Selection Recommendations

Key considerations:

Determine required safety category (ISO 13849-1)
Assess detection distance vs. resolution needs
Environmental factors (dust, temperature, vibration)
Integration with existing safety systems
Mounting options (fixed vs. adjustable brackets)

Industry Trends Analysis

Emerging trends include:

Integration with IIoT for predictive maintenance
AI-enhanced beam algorithms for reduced false triggers
Miniaturization for collaborative robot applications
Wireless safety protocols (e.g., Safety over EtherCAT)
Increased adoption in AGV obstacle detection

Real-world Application Case

In automotive assembly, SICK's OT series light curtains were implemented at a German plant to protect robotic welding cells. The system reduced unplanned downtime by 40% while maintaining SIL-3 safety compliance.