Overview
The Allen-Bradley 42EF-P2RCB-G4 is a RightSight cylindrical photoelectric sensor designed for polarized retroreflective detection in industrial automation systems. This 18 mm sensor provides stable, reliable light sensing with light-operate logic, ideal for presence detection, object counting, and positioning applications in manufacturing and conveyor systems.
Key Features
- Polarized Retroreflective Mode — Detects objects or reflectors with minimal interference from ambient light
- AC/DC Multi-Voltage — Operates across 21.6–264V AC/DC for flexible power integration
- N-MOSFET Output — Light-operate logic with 100 mA maximum output rating and short-circuit protection (SCP)
- 3-Meter Sensing Distance — Extended range ideal for large assembly or package detection
- Visible Red Light Source — Allows easy alignment and commissioning without special optics
- Compact 18 mm Cylindrical Housing — Front through-hole mount for panel or machine integration
Technical Specifications
- Voltage Input: 21.6–264V AC/DC @ 25 mA maximum (1 VA maximum)
- Output Rating: 264V AC/DC @ 100 mA maximum (SCP protected)
- Sensing Distance: 3 meters (9.8 feet)
- Light Source: Visible red LED
- Detection Mode: Polarized retroreflective
- Output Type: Light operate (MOSFET N-channel, normally open)
- Housing: 18 mm cylindrical, PBT plastic
- Mounting: Front through-hole with M18×1 threads
- Connection: 4-pin AC Micro QD quick-disconnect on 152 mm (6 in.) pigtail with 22 AWG conductor
- Operating Temperature: −10 to +50°C (standard industrial range)
- Certifications: C-TICK, CCC
- Weight: 0.25 lbs
- Series: RightSight 42EF
Typical Applications
The 42EF-P2RCB-G4 is widely used in:
- Package detection on conveyor systems and automated sorting lines
- Presence sensing in assembly and packaging machinery
- Position verification in material handling and transfer applications
- Bottle or container counting on high-speed bottling and filling equipment
- Edge or leading-edge detection in web processing and print applications
- Level sensing in hoppers and bins with reflector-based systems
Compatibility & Replacements
Compatible With
- Allen-Bradley CompactLogix and ControlLogix controllers with analog or discrete I/O
- Siemens S7-1200 and S7-1500 PLC systems via standard 24 VDC relay modules (5V logic translation may be required)
- Mitsubishi, Omron, and Schneider Electric PLC platforms supporting 100 mA sinking outputs
- Industrial motor starters and contactor logic circuits (direct hard-wired AC/DC rated devices)
- 24 VDC distributed control systems (verify voltage compatibility before installation)
- Motion control systems and servo-driven machinery requiring discrete presence verification
Replaces / Drop-In Replacement For
- 42EF-P2RCB-F4 — Identical sensor with 2 m cable instead of 6 in. pigtail; electrical specifications identical
- 42EF-P2RCB-A2 — Same sensor with 2 m cable without quick-disconnect; direct electrical drop-in
- 42EF-P2RCB-Y4 — Same sensor with 4-pin DC pico (M8) connector; requires voltage and output verification
Note: Dark-operate equivalents (42EF-P2SCB-G4) share identical mechanical and electrical specifications but reverse logic output; they are not direct replacements without software or relay logic modification.
Works With
- Studio 5000 — Standard discrete I/O module mapping (100 mA sinking output)
- TIA Portal — Siemens engineers configure via S7-1200/1500 signal card or relay output modules
- PROFIBUS and PROFINET — Retrofit via compatible I/O gateways or distributed terminal blocks
- EtherNet/IP — Requires mid-range CompactLogix or ControlLogix with EtherNet/IP enabled; wired as discrete input
- Modbus RTU/TCP — Indirect integration through discrete input mapping on supported PLCs
- Hardwired relay and contactor circuits — Direct connection to 24 VDC coils or AC-rated control circuits
















