Overview
The Allen-Bradley 1791-16B0 is a Series B block I/O module providing 16 discrete DC inputs in a sealed, compact package. This input module is engineered for use in remote I/O systems, offering reliable signal acquisition for PLC-5 and SLC controllers. With a 24V DC nominal input voltage rating and integrated 3.4 K Ohm input impedance, the 1791-16B0 delivers straightforward device connectivity without external signal conditioning.
Key Features
- 16 discrete DC input channels organized in two groups of eight
- 24V DC nominal input voltage with 10–30V DC operating range capability
- 3.4 K Ohm maximum input impedance for low-impedance sensor compatibility
- On-state input current 2.5–11 mA; off-state voltage limited to 5V DC maximum
- Sealed housing with removable terminal strip for field wiring
- DIP switch configuration for I/O rack and slot addressing
- Compatible with PLC-2, PLC-3, PLC-5, and SLC 5/02 controllers via Remote I/O scanner
Technical Specifications
The module supports a wide input voltage range and is configured for sinking and sourcing 24V DC field devices, including sensors, limit switches, and proximity detectors. Fast response times and integrated status LEDs provide real-time diagnostics. The compact footprint minimizes panel and enclosure space while maintaining full I/O capacity.
Typical Applications
- Discrete sensor and switch monitoring in material handling and packaging systems
- Field-mounted remote I/O for distributed automation architectures
- Machine tool and production equipment signal acquisition
- Facility and process monitoring on legacy PLC-5 and SLC networks
- Retrofit and expansion of existing Allen-Bradley control systems
Compatibility & Replacements
Compatible With
- Allen-Bradley PLC-5 series controllers
- Allen-Bradley PLC-3 and PLC-2 controllers
- SLC 5/02 and SLC 500 modular controllers (via Remote I/O scanner)
- Remote I/O (RIO) network scanner modules
- 1791 Block I/O series daisy-chain architecture
Replaces / Drop-In Replacement For
- 1791-16B0 (original release)
- Verify compatibility with your system integrator before ordering for legacy system integration.
Works With
- Allen-Bradley Remote I/O (RIO) network communications
- DH-485 communication protocol (via scanner)
- DeviceNet scanner modules for network integration
- RSLogix and Studio 5000 programming software for PLC-5 and SLC systems










