JNS18 / JNK18 Series M18 Diffuse Photoelectric Switch
Detection you can install from one side only: a standard M18 barrel that reads targets up to 3 m away with no reflector and no far-side wiring.
- Rated distance classes from 10 cm to 3 m
- One-sided mounting — nothing on the opposite side
- JNK18: built-in 300 mA output overload protection
- NPN / PNP; JNK18 DN2/DP2 give NO + NC together
- IP65, 10-30 VDC, standard M18 nut mounting
When Only One Side of the Line Is Yours
Racking bays, wide belts, truck-loading lanes and farm machinery share a problem: the far side of the detection path is unreachable, moving, or simply not worth the cable run. A through-beam pair or retroreflective sensor needs that far side. The JNS18/JNK18 family does not — emitter and receiver sit in one M18 barrel, and the target itself returns the light.
The JNS18 line (M18 x 68 mm, plastic housing) covers everyday 10/30/50 cm workstation checks at economy cost. The JNK18 line (M18 x 73 mm) stretches diffuse sensing to 1 m and 3 m classes and adds 300 mA output overload protection — the commissioning-stage insurance that survives a miswired load. Between them: seven range/series options, every one in NPN or PNP, all on 10-30 VDC with IP65 sealing.
Note: general-purpose presence detection only. JNS18/JNK18 are not IEC 61496-certified safety components and must not be used on their own for personnel protection.
One-Sided Rack & Conveyor Coverage
Original schematic: one JNK18 at the back of the bay covers the whole position; the range ladder shows where each series plays.
Sensing Head, Indicator and Distance Adjuster
Rear action indicator and distance adjustment knob; the twin-lens head keeps emitter and receiver in one M18 barrel.
Technical Specifications
| Sensing mode | Diffuse-reflective, one-sided mounting |
|---|---|
| JNS18 housing | M18 x 68 mm, plastic |
| JNK18 housing | M18 x 73 mm |
| Rated distances (JNS18) | 10 cm / 30 cm / 50 cm |
| Rated distances (JNK18) | 30 cm / 50 cm / 1 m / 3 m |
| Output codes | DN1 = NPN NO; DP1 = PNP NO; DN2/DP2: JNS18 = single NC, JNK18 = complementary NO+NC |
| Overload protection | JNK18: 300 mA built-in (not listed for JNS18) |
| Supply voltage | 10-30 VDC |
| Ingress protection | IP65 |
| Response time | Contact factory |
| Certifications | Contact factory (documents on request) |
Selection Tables — 28 Models
JNS18 (economy, 12 models) — DN2/DP2 are single NC outputs
| Rated distance | NPN NO | PNP NO | NPN NC | PNP NC |
|---|---|---|---|---|
| 10 cm | JNS18-10DN1 | JNS18-10DP1 | JNS18-10DN2 | JNS18-10DP2 |
| 30 cm | JNS18-30DN1 | JNS18-30DP1 | JNS18-30DN2 | JNS18-30DP2 |
| 50 cm | JNS18-50DN1 | JNS18-50DP1 | JNS18-50DN2 | JNS18-50DP2 |
JNK18 (long-range + overload protection, 16 models) — DN2/DP2 are complementary NO+NC
| Rated distance | NPN NO | PNP NO | NPN NO+NC | PNP NO+NC |
|---|---|---|---|---|
| 30 cm | JNK18-30DN1 | JNK18-30DP1 | JNK18-30DN2 | JNK18-30DP2 |
| 50 cm | JNK18-50DN1 | JNK18-50DP1 | JNK18-50DN2 | JNK18-50DP2 |
| 1 m | JNK18-100DN1 | JNK18-100DP1 | JNK18-100DN2 | JNK18-100DP2 |
| 3 m | JNK18-300DN1 | JNK18-300DP1 | JNK18-300DN2 | JNK18-300DP2 |
The DN2/DP2 suffix means different things in the two series (JNS18: single NC; JNK18: dual NO+NC). Double-check this line before ordering or wiring a "2" model.
Typical Applications
Rack / Pallet-Position Occupancy
Mounted at the back of a rack position, a JNK18 long-range model reports occupied/empty across the full pallet depth — one sensor, one side, no reflector strip to keep clean.
Wide Conveyor Object Detection
The 1 m and 3 m classes cover a belt from one edge, so cartons and bags trigger reliably without wiring the far side of the frame.
Workstation Part-in-Place Checks
The economical JNS18 10/30/50 cm models handle routine presence detection at assembly and inspection stations.
Agricultural / Logistics Equipment
Where only one side of the detection path is accessible, the JNK18-300D's 3 m diffuse throw is often the only practical option.
Frequently Asked Questions
What is the practical difference between JNS18 and JNK18?
JNS18 is the economy line: M18 x 68 mm plastic housing, rated distances 10/30/50 cm. JNK18 is the long-range line: M18 x 73 mm housing, rated 30 cm/50 cm/1 m/3 m, plus built-in 300 mA output overload protection that survives commissioning wiring mistakes. Both share the M18 mounting standard, 10-30 VDC supply and IP65 sealing.
Does a diffuse sensor this long-range need a reflector?
No — that is the appeal. Emitter and receiver live in one barrel and the sensor reads light bounced off the target itself, so only one side of the rack or conveyor needs mounting and wiring. For rack occupancy and wide belts this removes the reflector alignment and cleaning that retroreflective setups demand.
What do DN1 / DP1 / DN2 / DP2 mean — and why the warning between series?
DN1 = NPN normally open, DP1 = PNP normally open on both series. The '2' codes differ: on JNS18, DN2/DP2 are single normally-closed outputs; on JNK18, DN2/DP2 output complementary NO + NC simultaneously from one sensor. Confirm which behaviour you are wiring for before ordering a '2' suffix model.
Is the detection distance adjustable?
Each model has a rated distance class (10 cm to 3 m across the two series), and product hardware includes a sensitivity adjuster for trimming to the installation (per factory product imagery showing the adjustment knob and per-model detection windows). Set it so the target switches cleanly while floors and racks beyond stay out of range, and validate with the darkest target you handle.
Will it detect dark or matte cartons at full 3 m range?
Diffuse sensing depends on reflected light, so a dark, matte or angled target triggers at a shorter distance than the rating (which assumes a favourable target). If your farthest target is dark, choose the next range class up or run an on-site test — we can advise from your carton samples.
Can these be used for personnel guarding?
No. JNS18/JNK18 are general-purpose presence sensors — not IEC 61496-certified safety components — and must not be used alone for personnel protection. Use a certified safety light curtain for guarding.
How do I order, and are mixed-model trial batches possible?
Quote the full code, e.g. JNK18-300DP1 = JNK18 series, 3 m class, PNP NO. Mixed small batches for line trials (e.g. several distance classes to bench-test rack positions) are generally supported — contact the factory for MOQ, samples and current lead time.
Specs reviewed by Engineer Cai, Senior Application Engineer. See certificates.
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