Serviceline Industrial Sensors
Serviceline Explosion Protection

Retroreflective area sensor RLG28-55-4921/40a/73c/136

  • Retro-reflective area sensor with 6 light beams in standard photoelectric-sensor enclosure
  • Connection compatibly replaces single beam photoelectric sensor
  • Reliable detection of the front edge of the object irrespective of its shape and position
  • Constant object detection from 12 mm within the entire detection area
  • Reliable detection of all surfaces irrespective of the object texture
  • Switches when contrast difference 10%
  • Bright, highly visible transmitter beams guarantee convenient alignment of the sensor

Please note: All product-related documents, such as certificates, declarations of conformity, etc., which were issued prior to the conversion under the name Pepperl+Fuchs GmbH or Pepperl+Fuchs AG, also apply to Pepperl+Fuchs SE.

Download the complete datasheet as a PDF:

Datasheet excerpt: Technical data of  RLG28-55-4921/40a/73c/136

Product Description
Retroreflective area sensor with 6 beams in a widely used standard photoelectric housing, red light, 4 m detection range, light/dark on switchable, push-pull output, M12 plug
General specifications
Effective detection range0 ... 4 m
Reflector distanceReflector A80: 0.4 ... 4 m , H85-2 reflector: 0.2 ... 4 m , Foil reflector OFR-100/100: 0.4 ... 3 m
Threshold detection range5.6 m
Sensing rangetypical 60 mm , Object has to cover the refelector completely in one dimension
Reference targetReflector A80 H85-2 reflector Foil reflector OFR-100/100
Light sourceLED
Light typemodulated visible red light , 625 nm
Polarization filteryes
Number of beams6
Diameter of the light spotapprox. 220 mm at detection range 4 m
Angle of divergence+/- 2.5 °
Ambient light limit5000 Lux
Resolution12 mm
to 4 m Detection/capture range: 60 mm (no dead band)
5 mm
to 1 m Detection/capture range: 55 mm (dead band: 150 mm in front of the sensor; 50 mm in front of the reflector)
5 mm
to 1.5 m Detection/capture range: 40 mm (dead band: 150 mm in front of the sensor; 50 mm in front of the reflector)
Functional safety related parameters
MTTFd310 a
Mission Time (TM)20 a
Diagnostic Coverage (DC)0 %
Indicators/operating means
Operation indicatorLED green, statically lit Power on
Undervoltage indicator: Green LED, pulsing (approx. 0.8 Hz)
short-circuit : LED green flashing (approx. 4 Hz)
Function indicator2 LEDs yellow, light up when light beam is free, flash when falling short of the stability control, off when light beam is interrupted
Teach-In : LED yellow/green; equiphase flashing; 2,5 Hz
Changeover signal tracking: LED yellow, 1 Hz flashing / 2x flashing
Control elementsrotary switch for light/dark , Teach-In key
Electrical specifications
Operating voltage12 ... 30 V DC
Ripplemax. 10 %
No-load supply currentmax. 50 mA
Switching typelight/dark on, switchable
Signal output2 push-pull (4 in 1) outputs, complementary, short-circuit proof, reverse polarity protected
Switching voltagemax. 30 V DC
Switching currentmax. 100 mA
Voltage drop≤ 2.5 V DC
Switching frequency230 Hz
Response time1 ms
Product standardEN 60947-5-2
Approvals and certificates
UL approvalcULus Listed, Class 2 Power Source
CCC approvalCCC approval / marking not required for products rated ≤36 V
Ambient conditions
Ambient temperature-10 ... 40 °C (14 ... 104 °F)
-30 ... 60 °C (-22 ... 140 °F) at active signal tracking
Storage temperature-40 ... 70 °C (-40 ... 158 °F)
Mechanical specifications
Housing width25.8 mm
Housing height88 mm
Housing depth54.3 mm
Degree of protectionIP67
Connection4-pin, M12 x 1 connector
HousingPlastic ABS
Optical facePlastic pane
Mass100 g


ECLASS 11.027270910
ECLASS 10.0.127270910
ECLASS 9.027270910
ECLASS 8.027270910
ECLASS 5.127270910
ETIM 8.0EC002549
ETIM 7.0EC002549
ETIM 6.0EC002549
ETIM 5.0EC002549
UNSPSC 12.139121528

Documents: RLG28-55-4921/40a/73c/136

Instruction leafletsLanguageFile TypeFile Size
Instruction leaflet / Beipackzettel ALLPDF683 KB
Short instructions, safety information
RLG28: Alignment and Teach-In / RLG28 - Hinweise zur Ausrichtung und Teach-InALLPDF1086 KB

CAD+CAE: RLG28-55-4921/40a/73c/136

CADFile TypeFile Size
3-D model / 3-D-ModellSTP1019 KB
CAD Portal / CAD PortalLINK---

Approvals+Certificates: RLG28-55-4921/40a/73c/136

Statements of complianceCertificate No.File TypeFile Size
EU-Declaration of conformity / EU-KonformitätserklärungDOC-2257APDF86 KB
US CA UL General PurposeE87056LINK---

Associated Products: RLG28-55-4921/40a/73c/136


Female cordset single-ended M12 straight A-coded, 4-pin, PVC cable greyfa

Female cordset single-ended M12 straight A-coded, 4-pin, PUR cable greyfa

Female cordset single-ended M12 angled A-coded, 4-pin, PUR cable greyfa
Mounting aid for round steel ø 12 mm or sheet 1.5 mm ... 3 mmfa
Mounting bracket: mounting aid for sensors in the RL* seriesfa
Mounting bracket for rear wall mountingfa
dove tail mounting clampfa

Function: RLG28-55-4921/40a/73c/136

The RLG28 retro-reflective area sensor contains several transmitters and receivers in one housing and with a reflector positioned opposite forms a 60 mm detection area over a sensing range of 4 m.

When the light beams are interrupted by an object, the switching function is triggered. The smallest detectable object size is 12 mm. The RLG28 switches at a 10% contrast difference with a response time of 1 ms.