Overview
The Allen-Bradley 42CA-U1JNB-A2 is a compact 18 mm plastic cylindrical photoswitch retroreflective sensor engineered for general-purpose industrial sensing applications. This photoelectric sensor combines proven Rockwell Automation reliability with patented ASIC technology, making it ideal for light to medium duty automation environments where consistent, accurate object detection is required.
Key Features
- 18 mm industry standard enclosure for versatile mounting options
- Retroreflective sensing mode with maximum 7.2 m (23.6 ft) operating range
- Patented ASIC design for linear sensitivity adjustment and excellent noise immunity
- Two LED indicators: power status, output state, unstable operation, and short-circuit protection
- Stability indication with visual flash if signal level approaches detection threshold
- Simplified sensor alignment and background detection warnings
Technical Specifications
- Series: Bulletin 42CA Photoswitch
- Sensing Mode: Retroreflective
- Maximum Sensing Range: 7.2 m (23.6 ft)
- Enclosure Type: 18 mm cylindrical plastic
- Operating Status Indicators: Two LED (power, output, stability, short-circuit)
- Repeatability: ±3% per manufacturer specification
- Environmental Protection: IP67 rated
Typical Applications
- Parts presence and counting in assembly lines
- Object detection on conveyor systems with reflective targets
- Light-duty industrial automation and motion control
- Packaging and bottling machinery requiring retroreflective detection
- Position sensing with retroreflective labels or targets
Compatibility & Replacements
Compatible With
- Allen-Bradley CompactLogix, ControlLogix, and MicroLogix PLCs with digital input modules
- Siemens S7-1200, S7-1500 via adapter modules
- Omron and Mitsubishi industrial controllers with NPN/PNP input compatibility
- Any 10–30 VDC industrial control system with photoelectric sensor integration
- EtherNet/IP and PROFINET networks via industrial I/O gateways
Replaces / Drop-In Replacement For
- Verify compatibility with your system integrator before ordering to ensure proper input voltage and output type matching.
Works With
- Studio 5000 Logix Designer for Allen-Bradley integration
- RSLinx and RSLogix communication protocols
- Industrial photoelectric sensor harnesses and connectors (M12, circular, or pigtail)
- Retroreflective target labels and corner-cube reflectors
















