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Omron E3FB-RP21 — Photoelectric Sensors

Omron E3FB-RP21 Photoelectric Sensor, M12 PNP Retroreflectiv

MPNE3FB-RP21

Omron E3FB series retroreflective photoelectric sensor, M18 threaded, PNP output, M12 4-pin connector, 4 m sensing distance, mirror surface rejection, IP67/IP69K.

$34.16Ref. price · indicative, final on quote
Omron E3FB-RP21 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

E3FB-RP21 — Identification
ParameterValue
SeriesE3FB
E3FB-RP21 — Sensing
ParameterValue
Sensing methodRetroreflective
Response time0.5 msec
E3FB-RP21 — Electrical
ParameterValue
Supply voltage10-30V DC
E3FB-RP21 — Environmental
ParameterValue
IP ratingIP67; IP69K
Operating temperature, max.131 °F
E3FB-RP21 — Mechanical
ParameterValue
Body materialBrass
E3FB-RP21 — Approvals
ParameterValue
Standards / approvalsCE

Product details

The Omron E3FB-RP21 is a retroreflective photoelectric sensor in the E3FB series, delivering a 4 m sensing range with a PNP output. It connects via a 4-pin M12 connector—no cable to manage—so it swaps quickly in panels already wired with M12 receptacles. The Mirror Surface Rejection (MSR) feature helps avoid false triggers from shiny targets, a common headache on conveyor or packaging lines. Rated IP67 and IP69K, it handles washdown environments.

The closest functional sibling is the E3FB-RN112M, same retroreflective method, 4 m range, and MSR. The critical difference: the RP21 uses a PNP output with an M12 connector, while the RN112M is NPN with a 2 m prewired cable. If your IO card expects PNP, the RP21 is the drop-in; if the panel uses a cable gland and NPN, the RN112M needs no adapter. Wiring change is straightforward if swapping families—connector vs cable and output polarity are the only rewiring items.

Frequently asked questions

What is the closest second-source if I need a different output or connection?

The E3FB-RN112M shares the same sensing method (retroreflective, 4 m range) and MSR, but it uses NPN output and a 2 m prewired cable instead of the RP21's PNP and M12 connector. That makes it a functional alternative only if your system can accept the different output polarity and wiring style.

What is Mirror Surface Rejection (MSR)?

MSR is a feature that filters out false reflections from shiny or mirrored surfaces, letting the sensor reliably detect opaque objects without being fooled by the target's reflective finish.

Can the E3FB-RP21 replace an E3FB-RN112M without rewiring?

Not without changes. The RP21 uses a PNP output and an M12 connector, whereas the RN112M is NPN with a 2 m prewired cable. You would need to swap the connector (or add an M12 pigtail) and ensure the input card accepts PNP. If your card handles both, a terminal swap is possible.

MPN
E3FB-RP21