Overview
The Allen-Bradley 1794-OB16 is a discrete 24V DC output module in the FLEX I/O product family. This module features sixteen (16) 24VDC sourcing output channels, making it suitable for driving solenoids, pilot lights, and other low-voltage digital loads in industrial control cabinets and distributed I/O racks. The /A revision designation indicates the latest version. Used units are cost-effective alternatives for system expansion and replacement applications.
Key Features
- Sixteen 24VDC sourcing output channels
- 8 Amps total output current rating with 0.5 Amps per channel maximum
- Fast switching: 0.5 millisecond off-to-on, 1 millisecond on-to-off response time
- Compatible with 24VDC loads operating in the 19.2–31.2 VDC range
- Works with terminal bases including 1794-TB2, 1794-TB3, 1794-TB3S, 1794-TB3K, and 1794-TB3SK
- 16 yellow indicator LEDs for field-side status monitoring
Technical Specifications
- Output Voltage (Nominal): 24V DC (10V DC minimum, 31.2V DC maximum)
- Output Current: 8A total; 0.5A per channel maximum; 1mA minimum per channel
- On-State Voltage Drop: 0.5V DC maximum
- Off-State Leakage: 0.5 mA maximum
- Response Time: 0.5ms (off-to-on), 1ms (on-to-off)
- Isolation Voltage: 50V continuous
- Operating Temperature: -4°F to 131°F (-20°C to 55°C)
- Dimensions: 3.7 × 3.7 × 2.7 inches
- Weight: 78 grams (0.17 lbs)
- Mounting: Din-rail mount via 1794 terminal base
- Thermal Dissipation: 18.1 BTU/hour
- Bus Current (Backplane): 80 mA @ 5V DC
- Enclosure Type: Open-style, T3 IEC temperature rating
- Certifications: UL, CSA, CUL, CE, C-TICK, KC, GOST, MARINE
Typical Applications
The 1794-OB16 is widely deployed in manufacturing, food & beverage, automotive assembly, and chemical processing environments for:
- Solenoid and pilot light control
- Motor starter circuits and pump commands
- Discrete load switching in distributed I/O enclosures
- OEM equipment integration where FLEX I/O is the standard
- Retro-fit and expansion of existing CompactLogix/FlexLogix control systems
Compatibility & Replacements
Compatible With
- Terminal base units: 1794-TB2, 1794-TB3, 1794-TB3S, 1794-TB3K, 1794-TB3SK
- All 1794 FLEX I/O adapters for distributed I/O applications
- CompactLogix and FlexLogix controllers via FLEX I/O adapter modules
- RSLogix 5000 and Studio 5000 programming software
- EtherNet/IP networks (when used with appropriate FLEX I/O gateways)
Replaces / Drop-In Replacement For
- Original 1794-OB16 (non-/A versions)
- Earlier revisions of FLEX I/O 16-point sourcing modules
- Verify compatibility with your specific control architecture before ordering
Works With
- RSLogix 5000 and Studio 5000 ladder logic programming
- FLEX I/O distributed I/O communications protocol
- Allen-Bradley CompactLogix and FlexLogix PLC families
- Third-party EtherNet/IP gateways (with appropriate configuration)
