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Module Overview
The Allen Bradley 1794-TB3 is a Terminal Base Unit within the FLEX I/O system, serving as the essential mechanical and electrical interface between FLEX I/O modules and the field wiring connections. It provides a reliable, modular connection point for digital or analog I/O modules, simplifying installation, wiring, and maintenance in both centralized and distributed control applications.
Engineers value the 1794-TB3 for its tool-free modular assembly, secure wiring interface, and high vibration resistance, making it a cornerstone component in many industrial automation and process control systems.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Allen Bradley / Rockwell Automation |
| Product Series | FLEX I/O 1794 Series |
| Product Type | Terminal Base Unit |
| Number of Terminals | 36 (18 signal + 18 common terminals) |
| Connection Type | Screw clamp terminal |
| Terminal Wire Size | 0.34 – 2.5 mm² (22 – 14 AWG) solid or stranded wire |
| Compatible Modules | All 1794 FLEX I/O modules (digital, analog, specialty) |
| Communication Interface | Via FLEX I/O Adapter (e.g., 1794-AENT, 1794-ACN15) |
| Keying Positions | 1 through 8 (prevents incorrect module insertion) |
| Field Power Supply Voltage | 24V DC nominal |
| Isolation | Provided via system design and module isolation |
| Operating Temperature | 0°C to 55°C (32°F to 131°F) |
| Storage Temperature | -40°C to 85°C (-40°F to 185°F) |
| Humidity | 5–95% non-condensing |
| Enclosure Rating | IP20 (for use within enclosure) |
| Mounting Type | DIN rail |
| Dimensions (H × W × D) | 94 mm × 94 mm × 69 mm (3.7 in × 3.7 in × 2.7 in) |
| Weight | 0.15 kg (0.33 lb) |
| Certifications | UL, CE, CSA, C-Tick, Class I Div 2, ATEX |
Field Applications
The 1794-TB3 is a foundational part of any FLEX I/O system, used across industries where modular and scalable I/O design is required. Common applications include:
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Process Automation Systems – connects analog modules for process variables such as flow, temperature, or level.
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Machine Control – links digital modules to sensors, solenoids, and actuators.
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Distributed I/O Networks – supports remote I/O in EtherNet/IP, ControlNet, or DeviceNet topologies.
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Batch and Packaging Systems – allows quick module replacement with minimal downtime.
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Material Handling Equipment – simplifies distributed control wiring for conveyors or sortation systems.
Why Engineers Prefer the 1794-TB3
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Universal Compatibility: Works with a broad range of FLEX I/O modules, offering unmatched flexibility.
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Effortless Installation: DIN-rail mountable and supports tool-free assembly with interlocking bases.
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Simplified Maintenance: Modules can be hot-swapped without disconnecting field wiring.
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Reliable Connections: Screw clamp terminals ensure vibration-resistant, long-lasting wiring integrity.
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System Efficiency: Reduces wiring complexity and saves panel space for distributed I/O configurations.
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Built-In Keying: Prevents incorrect module installation and ensures wiring accuracy.
