Overview
The Allen-Bradley 42CA-U1KPB-D4 is a PHOTOSWITCH cylindrical photoelectric sensor from the proven 42CA family. This retroreflective unit combines compact 18 mm plastic construction with industrial-grade performance, making it ideal for machinery, material handling, and production line automation. The -U1KPB designation indicates retroreflective sensing with specific light/dark operate output configuration, while the -D4 suffix specifies the 4-pin DC micro M12 quick-disconnect connector for reliable field connections.
Key Features
- Retroreflective sensing method for detecting retroreflective targets
- 18 mm industry standard cylindrical plastic enclosure (IP67 rated)
- PNP output with complementary light operate (L.O.) and dark operate (D.O.) logic
- 4-pin DC micro (M12) quick-disconnect connector for fast installation and replacement
- Linear sensitivity adjustment with stability indication and excellent noise immunity
- Dual LED indicators for power, output status, unstable operation, and short-circuit protection
- Visible or infrared light source options depending on model variant
Technical Specifications
- Input Voltage: 10 to 30 VDC
- Maximum Output Current: 100 mA
- Sensing Method: Retroreflective
- Enclosure Size: 18 mm cylindrical, plastic
- Connection: 4-pin DC Micro M12 Quick-Disconnect
- Output Type: PNP (complementary L.O./D.O.)
- Ingress Protection: IP67
- Operating Temperature Range: -13 to 158°F
- Response Time: Typically 1–2 ms
- Humidity: 5 to 95% relative humidity (non-condensing)
- Vibration: 30 g with 1 ms pulse duration
Typical Applications
The Allen-Bradley 42CA-U1KPB-D4 is widely used in:
- Conveyor line presence detection with retroreflectors
- Box and package detection on production equipment
- Material handling and sorting systems
- Light to medium duty industrial machinery
- Position and object verification in automated assembly
- Safety interlock circuits and process monitoring
Compatibility & Replacements
Compatible With
- Allen-Bradley CompactLogix and ControlLogix controllers via standard 10–30 VDC wiring
- Siemens S7-1200, S7-1500, and LOGO! controllers (12/24 VDC input modules)
- Mitsubishi FX and Q series PLCs with appropriate input/output modules
- Omron NX and CJ series controllers with 24 VDC I/O cards
- Standard 10–30 VDC industrial automation I/O systems and motion controllers
- Distributed I/O networks requiring discrete PNP sensor inputs
Replaces / Drop-In Replacement For
- Allen-Bradley 42CA-U1KPB-A2 (same sensor with 2 m cable instead of M12 connector)
- Earlier Allen-Bradley retroreflective photoelectric models in the 42C_ family requiring 18 mm cylindrical form factor
- Generic OEM retroreflective sensors with PNP output and M12 connection in similar sensing range
Works With
- RS5000 Logix platforms and Studio 5000 engineering software for sensor configuration and diagnostics
- Retroreflective targets and reflectors (typically 3M-type corner-cube reflectors or similar)
- Standard M12 A-code connectors and quick-disconnect cables
- Industrial automation software monitoring PNP discrete inputs (FactoryTalk View, OPC servers, etc.)
- Programmable logic controllers supporting standard 10–30 VDC PNP sensors
