Safety Light Curtains

17 Series, One Decision Path

A safety light curtain is a pair of profiles that project a fence of infrared beams across a machine opening; break any beam and the curtain's outputs drop, stopping the hazardous motion before a hand reaches it. That one sentence covers all seventeen series below — what separates them is *which* opening, *which* body part, and *which* environment they are built for.

You do not need to read seventeen datasheets. Five questions eliminate series until one family remains: environment first (washdown? explosive atmosphere? outdoors?), then resolution (finger, hand or body detection), then protected height, then span and layout, and finally budget and housing space. The map below walks that exact path, and every stop on it links to a series card further down this page.

Pick by Resolution: 7.5 mm Finger Grade to 200 mm Perimeter

Resolution — the beam pitch — decides what the curtain can detect, which in turn decides how close to the danger point it may be mounted. The fine end of our range is the DQT4 family's 7.5 mm pitch (14 mm object detection, protective heights 90–5970 mm); the everyday workhorses are the DQC and DQA with eight pitches from 10 to 200 mm; the JER and MK economy lines cover 10–40 mm duties where the budget leads the specification.

The ladder below matches each pitch band to the body part it protects and the series that build it. As a rule of thumb: the finer the pitch, the closer the curtain may sit to the tooling — which is often the difference between a machine an operator can actually work at and one they have to reach around.

Pick by Housing: Ultra-Thin, Mini, and Zero Blind Zone

On retrofits, the mounting slot often chooses the series before any optical spec gets a vote. The DQB and its optically-synchronised twin DQBT run a 15 × 30 mm side-emitting profile that drops into an 18 mm gap between guide rails; the DQZ does the same trick front-emitting at 17.2 × 30 mm; the MK squeezes a full light curtain sensor into 25 × 23 mm for bench-top machines; the new MQ Essence Edition packs optical synchronisation — no wire at all between transmitter and receiver — into a 29 × 30 mm body with M12 plug-and-play cables. The DQO's speciality is its ends: first and last beams sit just 6.75 mm from the housing tips, so the protected field can start almost flush against a machine shoulder — the answer when a standard curtain's end blind zone would leave a reachable gap.

The cross-sections below are drawn to a common scale. If your slot is the constraint, start here and let the profile pick the family; the optical specs inside each family then follow the resolution logic above.

Pick by Span and Coverage: 3 m Standard to 40 m, and Mirror-Folded Perimeters

Standard optical ranges run 0.3–3 m or 0.3–6 m, which covers most feed openings. Long beds and transfer lines step up to the DQA and DQT long-range grades, whose detection-distance classes reach 0.3–40 m; the DQT additionally scales to 72 beams for tall access ways.

Perimeter work changes the geometry rather than the range: the DQSA area-protection system takes one transmitter/receiver pair plus one to three corner mirrors and folds the beams around two, three or four sides of a robot cell — protective heights to 3920 mm at 40 or 80 mm pitch, with one wiring point instead of four. For an industrial safety light curtain layout around a full cell, that mirror trick is routinely the difference between a tidy installation and a cable-tray project.

Harsh Environments: Waterproof and Explosion-Proof

Washdown lines take the DQR, whose 36 × 36 mm housing is IP65 as standard, with the DQRF special-order variant sealed to IP68 for lines that are hosed rather than wiped. For classified atmospheres, the FB explosion-proof series repackages our curtain optics in Ex-rated enclosures as an engineered-to-order build — describe the zone and the gas/dust group in the inquiry and the factory returns the matching construction rather than a catalogue guess.

Outputs and Getting Into the Stop Circuit

Electrically, the transistor-output families follow one discipline: NPN or PNP, 500 mA switching capacity, residual voltage under 1.5 V, with polarity, short-circuit and overload protection built in. Relay-output versions (and the controller-based systems) take AC 110–220 V supply and hand you dry contacts instead. The DQO and DQT4 families carry dual OSSD safety outputs for two-channel evaluation.

The chain downstream is always the same shape: curtain outputs feed a safety relay or safety controller, whose force-guided contacts drive the machine contactors. Our DA31 and DQSRN safety relay modules are the catalogue-matched evaluation stage. If NPN-versus-PNP is the open question in your panel, the output polarity guide settles it in five minutes.

Full wiring diagrams for every output type — including channel-by-channel drawings and reset options — are maintained in the DAIDISIKE engineering library on fsddsk.com; this page deliberately stays above pin level.

Type Ratings, Stated Honestly

Across this category the design baseline is the Type 4 architecture of IEC 61496 — dual-channel outputs and continuous self-monitoring on the families that carry it, stated on each series page in exactly those words. We write "designed to the Type 4 architecture" rather than waving certificates on a category page, because the certificate that matters is the one matched to the exact configuration you order, and those documents are supplied with the order paperwork. The JER and MK economy lines describe their levels in their own words on their own pages; the DD diffuse-reflection curtains are detection devices, not personnel protection, and say so prominently.

If you are deciding how much Type you actually need to buy — where a Type 2 device is legitimately sufficient and where Type 4 is the only defensible choice — the guide Type 2 vs Type 4 Safety Light Curtains covers the fault-behaviour difference, the PL mapping and the decision path in full.

Safety, Measuring, or Press-Brake? Don't Buy the Wrong Family

Three product families on this site share the light-curtain silhouette and share nothing else. This page is personnel protection. If the job is dimensioning, counting or profiling — data, not stopping machines — you want the measuring light curtains, which carry no safety rating on purpose. And if the machine is a hand-fed press brake, a fixed curtain is the wrong physics entirely: the press & press brake protection systems move the guard with the ram. Thirty seconds spent here saves the classic wrong-family purchase.

Know your opening width × height and required resolution? Send those two numbers and the machine type via the inquiry form — the reply is a part number like DQC06/10-50 with the documentation list.

Frequently Asked Questions

Safety Light Curtains in Action — 10 Demonstration Videos

Wiring, setup and live operation filmed on the actual modules. Each clip links back to the series it demonstrates, so you can go straight from footage to specification.

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Selection Help & Related

📘 Not sure which series? How to Choose a Safety Light Curtain · Type 2 vs Type 4 Safety Light Curtains

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