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Safety Light Curtains for Machine Guarding
CCH ENT Series safety light curtains provide 14, 25 and 45 mm detection-resolution options for point-of-operation and access safeguarding. The current ENT platform is designed as a Type 4 safety light curtain family for industrial machine guarding.
Three Resolution Options
Select the detection resolution according to the safeguarding requirement, machine opening and required safety distance.
Three ENT Resolution Platforms
Resolution is one of the first parameters to determine when selecting a safety light curtain. ENT Series is available in 14, 25 and 45 mm detection-resolution platforms with different protection-height ranges.
Fine-Resolution Detection
The finest detection-resolution platform in the current ENT range, intended for applications requiring detection of smaller objects within the protected field.
Medium-Resolution Detection
A middle-resolution platform providing a wider protection-height range while maintaining a smaller detectable-object size than the 45 mm platform.
Access-Oriented Detection
The widest detection-resolution platform in the ENT range, supporting taller protected fields for access and opening safeguarding applications.
Designed for Faster Setup and Reliable Machine Safeguarding
ENT Series combines safety-rated OSSD outputs with optical synchronization and configurable operating functions designed to simplify installation, commissioning and maintenance.
Optical Synchronization
The emitter and receiver communicate through optical synchronization, reducing the need for a dedicated synchronization wire between the two sensor units.
PNP / NPN Configurable OSSD
The receiver supports selectable PNP or NPN output modes, helping adapt the safety light curtain to different machine control architectures.
CH-A / CH-B Optical Channels
Two configurable optical synchronization channels help reduce interference risks when multiple ENT light curtains are installed in nearby positions.
Long / Short Range Mode
Receiver sensitivity can be switched between long-range and short-range operating modes to support different installation distances and reduce interference in close-range applications.
Infrared Configuration
Selected operating functions can be configured through infrared communication using a compatible smartphone or an optional infrared remote controller.
Multi-Level Status Indication
Receiver indicators provide visual information for beam interruption, operating status, output mode, optical channel, received-light level and segment status.
Extend the ENT Platform for More Complex Guarding Layouts
Selected ENT configurations support additional safeguarding functions for machines with multiple openings, moving process elements or multi-sided access requirements.
Cascading
Multiple ENT safety light curtains can be connected through cascading adapters to create a coordinated safeguarding arrangement for larger or more complex machine layouts.
Floating Blanking
A configured number of beams can be permitted to remain interrupted without immediately switching the OSSD to the OFF state, subject to the selected blanking logic and configuration conditions.
Multi-Side Protection
Reflective column components can be used to redirect the protective beam path and create multi-sided guarding around selected machine areas using one ENT light curtain system.
The Blanked Position Does Not Need to Be Fixed
With floating blanking, the permitted interruption can move within the detection field rather than being assigned to one permanently fixed beam position. The OSSD response depends on the configured number of blanked beams and the selected operating logic.
Blanking changes how selected beam interruptions inside the protective field are evaluated.
Muting refers to a controlled temporary bypass of a safety function under defined machine or material-transfer conditions. These functions should not be treated as interchangeable.
Machine Guarding Across Real Industrial Applications
ENT safety light curtains create a monitored access plane between personnel and hazardous machine motion while allowing frequent loading, unloading and production access without a physical door.
Press Machine Guarding
A light curtain can monitor operator access to the point of operation while maintaining an open working area for loading and unloading parts.
Machine Access Protection
Safety light curtains can monitor open machine access areas where operators need regular interaction with the process but hazardous motion must remain protected.
Automated Production Lines
ENT light curtains can protect access points around automated machinery, transfer stations and production cells where personnel and machine processes share nearby space.
Select the Safeguard Around the Machine Task
The same ENT platform can be configured in different sizes and resolutions according to the access point, protected opening and required safety distance.
Press Brakes
Protect operator access around bending operations while preserving practical access to the working area.
Robot Cells
Monitor personnel entry through selected openings in guarded robotic and automated manufacturing cells.
Material Transfer
Protect openings around conveyors, transfer stations and automated material-flow equipment according to the required guarding logic.
The required resolution, protection height and installation distance depend on the specific machine hazard and risk assessment. Application type alone is not sufficient to determine the final light-curtain model.
View All Applications →Functional Safety and EMC Evaluated Separately
ENT Series safety performance and electromagnetic compatibility are supported by separate third-party evaluations. This distinction helps machine builders understand what each certificate actually covers.
SGS-TÜV Saar
Functional safety certification for the ENT Series safety light curtain platform, covering the safety architecture and performance requirements relevant to machine safeguarding.
TÜV Rheinland
Electromagnetic compatibility evaluation for identified ENT safety light curtain models under the EU EMC framework.
Different Standards Address Different Parts of the Safety Function
Type, Category, Performance Level and SIL should not be treated as interchangeable labels. They describe different aspects of product and safety-system performance.
ENT Series Technical Data
Category-level specifications are shown below for initial engineering selection. Protection height, response time and other model-dependent values should be verified against the selected ENT model.
| ESPE Type | Type 4 · IEC 61496 |
|---|---|
| Category | Cat. 4 · ISO 13849 |
| Performance Level | PL e · ISO 13849 |
| Safety Integrity Level | SIL 3 · IEC 61508 |
| PFH | 1.42 × 10⁻⁸ |
| Hardware Fault Tolerance | HFT = 1 |
| Diagnostic Coverage | >99% |
| Diagnostic Test Interval | <10 minutes |
| Light Source | Infrared LED · 850 nm center wavelength |
|---|---|
| Detection Resolution | 14 mm / 25 mm / 45 mm |
| Beam Spacing | 10 mm / 20 mm / 40 mm |
| Protection Height | Model-dependent · up to 1960 mm ENT14, ENT25 and ENT45 have different model ranges. |
| Synchronization | Optical synchronization |
| Optical Channels | CH-A / CH-B configurable |
| Range Mode | LONG / SHORT configurable |
| Operating Voltage | 24 V DC ±20% |
|---|---|
| Emitter Current | <200 mA |
| Receiver Current | <200 mA · no load |
| Safety Output | 2 × OSSD |
| Output Type | PNP / NPN configurable |
| Maximum Output Load | ≤100 mA per output |
| Startup Time | <3 s |
| Protection Functions | Overvoltage · overcurrent · output short-circuit protection |
| Protection Rating | IP65 |
|---|---|
| Profile | 34 × 28 mm |
| Operating Temperature | −10°C to +55°C No frost or condensation on the optical surface. |
| Storage Temperature | −40°C to +70°C |
| Operating Humidity | 35–85% RH |
| Storage Humidity | 35–95% RH |
| Incandescent / Fluorescent | 3,000 lux |
| Sunlight Immunity | 10,000 lux |
Select Distance by Configuration
The current product-number structure lists A, B and C distance configurations. For applications outside these ranges, confirm the currently available configuration with CCH Engineering.
Select the Light Curtain from the Machine Risk Backwards
The application name alone does not determine the correct safety light curtain. Start with the required detection capability, then verify protection height, sensing distance, overall response time and the required separation distance.
Select Resolution
Determine the minimum detectable object size required by the machine safeguarding design and risk assessment.
Select Protection Height
Measure the machine opening or access area that must remain inside the protective field.
Confirm Sensing Distance
Measure the actual emitter-to-receiver installation distance and select an appropriate currently available ENT distance configuration.
Determine Overall Response Time
Account for the selected light-curtain response, safety-related control response, machine stopping performance and applicable response-time tolerance.
Determine Separation Distance
Evaluate approach speed, overall response time, reaching through, over or under the protective device, and any application-dependent supplemental distance.
Separation Distance Is More Than Stop Time and Resolution
The current calculation structure considers the overall response time together with the applicable reaching-distance allowance and supplemental distance. Reaching over, through and under the protective device must be evaluated for the actual machine geometry.
Flexible Mounting for Different Machine Structures
ENT safety light curtains support multiple mounting arrangements for machine frames, production equipment and guarded openings. Final installation should provide stable alignment and maintain the required protective-field geometry.
Front / Side Mount
Integrated bracket arrangement for mounting the light curtain from the front or side of the machine structure.
Magnetic Mount
Magnetic brackets provide an alternative installation method for compatible machine structures where magnetic mounting is appropriate.
Pipe Mount
Pipe mounting provides a dedicated support structure when the light curtain cannot be mounted directly to the machine frame.
T-Slot Mount
T-slot brackets provide an adjustable mounting direction for machine frames and structures using compatible slot systems.
Protective Cover
A protective cover can be added where the light curtain needs additional mechanical shielding from nearby machine activity.
Mount, Align and Verify Before Operation
Correct mechanical installation is only the beginning. Alignment, signal strength and beam-interruption behavior must be verified before the safety light curtain is placed into service.
Use the LEVEL Indicators to Confirm Alignment Margin
Beam alignment should not be judged only by whether the OSSD reaches the ON state. The receiver LEVEL indicators provide additional information about received-light strength and help establish a more stable installation.
Tell Us What Your Machine Needs to Protect
Send CCH the basic machine layout and safeguarding requirements. We can help narrow the ENT resolution, protection height, sensing-distance configuration and installation direction for preliminary project selection.
If the exact ENT model is not yet known, send the application information first. Model selection should follow the actual hazard and machine geometry.
Six Inputs for Faster Preliminary Selection
A machine photo or layout drawing is also useful where the guarded opening or mounting arrangement is difficult to describe in text.
