Light barriers, light grids or optosensors?
The right closing edge safety device for your door
For garage doors, sectional doors, roller doors & high-speed doors – the big comparison from Tormeister 24.
Light barriers, light grids, optosensors – what’s what?
Light barriers (incoming or reflective)
A light barrier monitors a line – either as a one-way version (transmitter ⇄ receiver) or as a retro-reflective version (transmitter/receiver in the same housing + reflector). Ideal for passage control and additional security at the opening level. Models like the SOMMER 5233 (IP67, polarizing filter) are robust and resistant to ambient light.
Advantages: streamlined installation, affordable retrofit, proven technology. Limitations: Only secures one line, not the entire gate area.
Light grid (multi-beam protective field)
Light grids create a protective field from multiple infrared beams, thus protecting the entire height and width. This is the gold standard for high-traffic industrial doors or high-speed doors. Series such as Marantec GridScan/Pro are available in 1.96 m and 2.5 m protective field heights and with common interfaces (PNP/NPN/OSE).
Optosensors on the closing edge
Optosensors are located in the rubber profile of the moving closing edge. If the light beam in the profile is interrupted (contact), the door stops and reverses – highly effective against crushing and shearing points.
The OSE connection is widely used (e.g., Marantec F transmitter/F receiver, OSE-coded). Radio-controlled accessories (e.g., radio-controlled wicket door contact) are also available.
Special ATEX light barriers are available for Ex zones (e.g. reflex versions for Zone 1/2).
Comparison table: Which solution is suitable for what?
| criterion | light barrier | Light grid | Optosensor (closing edge) |
|---|---|---|---|
| Safety principle | Monitors one line (through-beam or reflex with reflector) | Multi-beam protective field (e.g. 1.96–2.5 m height) | Sensor in the closing edge (OSE/optical, alternatively 8.2 kΩ contact strip) |
| cover | Line detection, good as passage or additional security | Area detection (complete opening), ideal for pedestrian traffic | Directly at the danger point (moving edge) |
| Typical connections | Relay/changeover contact, 2-wire/4-wire (depending on model) | PNP / NPN / OSE (depending on model, e.g. GridScan/Pro) | OSE (optically coded) or 8.2 kΩ (resistive) |
| Strengthen | Simple, cost-effective, flexible retrofittable | Maximum personal safety in the opening plane, ideal for high-speed/industrial doors | Maximum effectiveness directly at the pinch point; standard-compliant solution at the closing edge |
| Limits | Does not secure an area, only a line | More complex than a single light barrier, possibly accessories (cables/covers) | Primarily protects the edge, not the opening plane |
Examples: GridScan/Pro 1.96 m & 2.5 m with PNP/NPN/OSE options; SOMMER 5233 (IP67) ; F-Receiver OSE .
Ordering guide: 5 steps to the right closing edge safety device
- Door type & use – private garage (occasionally), industrial door/high-speed door (frequent, pedestrian traffic).
- Area to be secured – opening level (→ light grid), passage line (→ light barrier), moving closing edge (→ optosensor/OSE).
- Check interface – your controller: OSE? PNP/NPN? 8.2 kΩ? (e.g., GridScan/Pro supports PNP/NPN/OSE).
- Environment – Outdoor, IP protection, Ex zone (ATEX models).
- Order accessories – covers, fastening/mounting brackets, control/connection cables (e.g. protective cover set; note: range −20% ).
Quick Match:
• Garage door – passage photocell + closing edge sensor for the edge.
• Industrial/high speed – light grid with 2.5 m field + OSE/PNP/NPN after control.
• Ex area – ATEX reflex light barrier .
Practice: proven setups from projects throughout Germany
- Logistics ramp – throughput > 200 openings/day: light grid (GridScan/Pro) + protective cover + OSE cabling, optional extension cable for synchronization.
- Private garage with bicycle traffic – reflex photoelectric barrier (polarizing filter, IP67) for passage monitoring; an OSE optosensor with an F-profile (e.g., P1/P2/P6) on the lower edge.
- City center parking gate – one-way photoelectric sensors with mounting brackets + pull-in protection (OSE) on the edge for redundant safety.
Product link hub (all verified & ready to click)
Light barriers – complete list (23 items)
- One-way photoelectric sensor 12–24 V, 20 m, IP55, rotatable (SOMMER 99738)
- Weatherproof housing reflector (SOMMER 5234V000)
- Retroreflective photoelectric sensor 12 m, IP67, polarizing filter (SOMMER 5233)
- Retroreflective photoelectric barrier 21 m (SOMMER 5228)
- Marantec Special 630 – One-way photocell for frames (2 mm)
- Marantec Special 630 – 8 m, 2-wire, 2×10 m cable
- Marantec Special 630 – One-way photocell for frames (1 mm)
- Marantec Special 633 R – 20 m, 4-wire (without cable)
- Marantec Special 633 L – 20 m, 2-wire (without cable)
- Marantec Special 633 L – 20 m, 2-wire, 20 m cable
- Marantec Special 633 – 8 m, 2-wire (without cable)
- Marantec Special 633 – 8 m, 2-wire, 20 m cable
- Marantec mounting bracket set of 2 (one-way photocells)
- Marantec mounting bracket set Special 630
- Marantec one-way photocell 24–240 V, 10 m (with brackets)
- Marantec one-way photocell 12–24 V, 10 m (with cable)
- Marantec Special 630 – 8 m (with mounting bracket)
- Marantec Ex-photocell Reflex (Zone 1/2, 8 m)
- Marantec Ex-proof photocell Reflex IP67 (Zone 1/2, 8 m)
- Marantec pull-in protection 10 m, 24 V‑DC (OSE)
- Marantec Special 670 (2× 2-wire LS at one input)
- Marantec Special 613‑2 Reflex, 8 m, 2‑wire
- Pro‑Line drive-through photoelectric barrier
Light curtains – complete list (13 articles)
- Light grid connection cable 10 m
- Mounting set 90° for GridScan/Pro
- Mounting set clips (rear wall) for GridScan/Pro
- Marantec GridScan/Pro 1,960 m (PNP/NPN/OSE)
- Marantec GridScan/Pro 2,500 m (PNP/NPN/OSE)
- Protective cover set 1,960 mm (-20% range)
- Protective cover set 2,500 mm
- Extension sync cable 10 m
- Extension sync cable 3 m
- Extension sync cable 5 m
- Pro‑Line CND1 control cable
- Pro‑Line light grid GS‑Pro <10 m width / 2.8 m height
- GS‑Pro control cable 6P – 5 m
Optosensors & closing edge – representative core products (selection)
- Marantec F-Profil P1 (11 mm optical sensors, 50 m)
- Marantec F-profile P2 (11 mm, 25 m)
- Marantec F-profile P4 (22 mm, 25 m)
- Marantec F-profile P6 (11 mm, 25 m)
- F-spacer sleeve 11/22 mm (with steel insert)
- Door end profile 29×58 mm (2 chambers, 14 mm optosensors)
- Door end profile 30.2×40 mm (1 chamber, 22 mm optosensors)
- SOMMER end cap with 2.5 m cable (for 8.2 kΩ contact strip)
- SOMMER aluminum K-rail 1000×30×10 mm
- Marantec F‑Transmitter OSE – 0.5 m cable
- Marantec F‑Transmitter OSE – 4 m cable
- Marantec F‑Transmitter OSE – 10.5 m cable
- Marantec F‑Transmitter OSE – 6 m cable
- Marantec F-receiver OSE – 0.4 m cable
- Optosensor set: transmitter 10.5 m / receiver 0.4 m
- Optosensor set: transmitter 10.5 m / receiver 1 m
- Optosensor set: transmitter 15 m / receiver 0.4 m
- Optosensor set: transmitter 6.5 m / receiver 0.5 m
- Safety contact strip 8.2 kΩ (configurable)
- Marantec wireless wicket door contact 868 MHz (IP55)
- 6-core connecting cable with plug (TBAD)
- Connecting cable for door leaf connection boxes 10 m
- Protect‑Switch 190 door leaf connection box
- Sealing set IP65 for door leaf junction boxes
- Marantec Protect‑Opto 602 – leading photocell
The complete collection (85 items) can be found here: Optosensors & Closing Edge Safety Devices .
FAQ – frequently asked questions
Is a photocell on my garage door sufficient?
It's a great solution for controlling passage. For the moving closing edge, we recommend an additional OSE optosensor or an 8.2 kΩ contact strip – this provides direct protection at the danger point.
How do I choose the right interface (OSE/PNP/NPN)?
Check the control system documentation: If an OSE input is available, OSE solutions are particularly simple. Many light grids (e.g., GridScan/Pro) offer PNP/NPN/OSE, so you remain flexible.
Outdoor areas & dirt – what to consider?
Pay attention to IP protection and covers. Protective covers are available for GridScan/Pro (note: range -20%). For light barriers, polarizing filters help protect against ambient light.
Ex-zone?
Only use ATEX-compatible products, e.g., special explosion-proof light barriers.
Contact & Advice
Unsure which solution is right for your control system? Our team can help you quickly and practically.
Contact & Customer Service – Tormeister 24
