Overview
The Allen-Bradley 42SRU-6204 is a Series 6000 photoelectric sensor designed for polarized retroreflective sensing applications. This compact photoswitch operates across a wide voltage range (20-132V AC/DC) and uses a visible red LED for reliable object and reflective surface detection. The unit features a standard 3-meter cable connection and light-operate configuration, making it ideal for machine automation, conveyor systems, and material handling equipment where consistent part positioning is critical.
Key Features
- Polarized retroreflective sensing technology for reflective surface/object detection
- Operates on 20-132V AC/DC with 35 mA maximum current draw
- Visible red 550 nm LED indicator for easy troubleshooting
- 3-meter sensing distance (50.8 mm minimum reflector spacing)
- Light-operate mode (activates when light received from retroreflector)
- Compact industrial-grade housing for DIN rail or panel mounting
Technical Specifications
- Input Voltage: 20–132V AC/DC
- Output Current: 35 mA maximum
- Detection Mode: Polarized Retroreflective (Light Operate)
- LED Color: Visible Red (550 nm wavelength)
- Maximum Sensing Distance: 3 meters (9.8 feet)
- Minimum Reflector Distance: 50.8 mm
- Cable Length: 3 meters with 300V rated insulation
- Series: Allen-Bradley Series 6000 Photoswitch
- Output Type: Power MOSFET
- Connector Type: Standard 3-meter cable (QD connector variant available as 42SRU-6204-QD)
- Operating Temperature: Industrial duty-rated
Typical Applications
The Allen-Bradley 42SRU-6204 is commonly used in:
- Conveyor and automated material handling systems requiring object presence detection
- Assembly line equipment for part positioning and alignment verification
- Packaging machinery where reflective labels or retroreflectors are used
- Count and sorting applications with retroreflective targets
- Industrial control logic requiring discrete sensor input signals
Compatibility & Replacements
Compatible With
- Allen-Bradley CompactLogix, ControlLogix, and MicroLogix PLCs via discrete 24V input modules
- Any industrial controller with 20-132V discrete input capability
- Standard analog/digital I/O cards supporting photoelectric sensor signals
- DIN rail mounted control enclosures and panel-mount industrial systems
- Retroreflectors and reflective targets (standard industrial types)
Replaces / Drop-In Replacement For
The 42SRU-6204 directly replaces earlier Allen-Bradley Series 6000 photoswitch units with identical voltage and sensing specifications. Verify connector compatibility (standard cable vs. QD) with your installation before ordering. The QD variant (42SRU-6204-QD) provides quick-disconnect 4-pin Micro connector for tool-less field replacement.
Works With
- Allen-Bradley Studio 5000 (logic programming and I/O configuration)
- Allen-Bradley RSLogix 5000 for ControlLogix-based systems
- Standard industrial PLC discrete input modules (24V sensor input cards)
- EtherNet/IP and ControlNet networks via PLC gateway modules
- Any voltage-agnostic relay logic or hard-wired control systems
