1794-TB3GS FLEX I/O Terminal Base Unit | Allen-Bradley

Configured for signal distribution and modular I/O connectivity in FLEX I/O systems, the Allen-Bradley 1794-TB3GS (1794-TB3GS Terminal Base) provides direct physical/electrical execution of field wiring termination.

Hardware Specifications

Profinet / EtherNet/IP Deterministic Networks

The 1794-TB3GS acts as a passive interconnection point within the FLEX I/O architecture. It facilitates the routing of field signals to the installed I/O modules while maintaining the electrical integrity required for deterministic network communication. The base supports backplane bus communication by providing mechanical alignment and electrical pins for the module-to-module interlink. Proper seating of the module into the base is required to ensure consistent communication velocity and prevent signal attenuation across the backplane bus.

Frequently Asked Questions (FAQ)

Q: What is the primary difference between this and screw-clamp terminal bases?

A: The 1794-TB3GS utilizes spring clamp technology, which provides vibration resistance for field wiring without the need for periodic torque verification.

Q: Does this base support hot-swapping of I/O modules?

A: Yes. The 1794-TB3GS supports the removal and insertion of compatible 1794 I/O modules while the system is powered. However, ensure that the module is fully latched to the base to establish reliable electrical contact with the backplane bus.

Field Installation Guidelines

• DIN-Rail Mounting: The terminal base is designed for standard 35 mm DIN-rail mounting. Ensure the rail is securely grounded to the enclosure backplane to provide a common reference for the system shield.

• Wiring Termination: Utilize appropriate wire gauges for the spring clamp terminals to ensure secure mechanical retention. Strip insulation according to the specified depth to prevent exposed conductors while maintaining contact surface area.

• Common Terminals: Utilize the 2 common and 2 voltage terminals provided on the base to distribute power to field devices. Ensure the total current load across the base does not exceed 10.0 A to prevent thermal degradation of the terminal interconnects.

• Environment: As an IP20 rated open-style component, the unit must be installed within a cabinet or enclosure providing adequate protection against conductive dust, moisture, and extreme temperatures.