Overview
The Allen-Bradley 1794-TB2 is a terminal base unit for the Flex I/O 1794 series, providing secure field wiring termination in compact, modular form. The 1794-TB2 accommodates standard 2-wire connections through cage clamp terminals rated for 24–16 AWG (0.21–1.3 mm²) copper wire. This unit houses 18 common I/O terminals plus 2 dedicated voltage supply terminals, supporting up to 10A per terminal at 125V AC/DC continuous. Typical applications include motor control, sensor inputs, solenoid drives, and distributed I/O in Allen-Bradley PLC systems using the FLEXBUS protocol.
Key Features
- 18 common + 2 voltage terminals for flexible field wiring configurations
- Cage clamp termination accommodates 24–16 AWG stranded or solid copper wire
- 10A per terminal maximum current capacity for reliable, high-density I/O
- 125V AC/DC rating with continuous isolation voltage of 125V
- DIN rail and panel mounting options for flexible enclosure integration
- UL listed (File E65584) and CSA/CE certified for North American and international deployments
Technical Specifications
- Product Type: Flex I/O Terminal Base Unit
- Voltage Rating: 125V AC/DC, 50/60 Hz
- Continuous Isolation Voltage: 125V
- Maximum Current per Terminal: 10A
- Terminal Count: 18 common + 2 voltage terminals (20 total)
- Wire Size: 0.21–1.3 mm² (24–16 AWG) solid or stranded copper
- Maximum Insulation Thickness: 1.2 mm (3/64 in.)
- Terminal Screw Torque: 0.56–0.79 Nm (5–7 lb-in)
- Termination Type: Cage clamp (screwless)
- Operating Temperature: 0–55 °C
- Storage Temperature: −40–85 °C
- Operating Shock: 30 g
- Non-operating Shock: 50 g
- Dimensions: 94 × 94 × 69 mm (H × W × D)
- Mounting: DIN rail and panel mounting
- Certifications: UL Listed (File E65584), CSA, CE, C-TICK
Typical Applications
- Motor and Drive Control – discrete I/O for 3-phase motor starters and soft starters
- Sensor Input Termination – proximity sensors, limit switches, pressure transducers
- Solenoid Control – valve pilots, proportional solenoid outputs
- Distributed FLEXBUS I/O – remote I/O expansion via Allen-Bradley FLEX I/O adapter modules
- Pneumatic and Fluid Control – solenoid valve control with integrated I/O modules
- Machine Tool Automation – compact I/O termination for CNC and spindle control
Compatibility & Replacements
Compatible With
- Allen-Bradley Compact Logix, CompactLogix 5370, CompactLogix 5380 (with 1794-AEN communication module)
- ControlLogix 5000 and ControlLogix 5500 controllers via FLEXBUS (1794-AENT, 1794-ASB modules)
- MicroLogix 1200/1500 with gateway modules
- 1794 series remote I/O modules (all variants compatible with this base)
- FLEXBUS protocol and distributed I/O networks
- Studio 5000 and RSLogix 5000 configuration software
Replaces / Drop-In Replacement For
- Earlier 1794-TB2 revisions (all /A, /B, /C revisions are functionally equivalent)
- Custom terminal blocks in legacy systems when migrating to Allen-Bradley distributed I/O
Works With
- Studio 5000 and RSLogix 5000 for I/O module configuration
- FLEXBUS communication protocol (1794 series adapters)
- EtherNet/IP via compatible 1794 gateway modules
- Standard industrial 24–16 AWG field wiring and connectors
- DIN rail and panel enclosures for modular automation systems
