Configured for field termination and module interface execution in FLEX I/O network architectures, the Allen-Bradley 1794-TBNF (1794-TBNF Fused Terminal Base Unit) provides direct physical/electrical execution.
Hardware Specifications
Parameter
Specification
Model
1794-TBNF
Brand
Allen-Bradley
Origin
USA
Weight
0.44 lbs (0.20 kg)
Dimensions
Standard FLEX I/O footprint
Operating Temp
0 to 55 deg C
Voltage Rating
250 VAC/DC
Current Rating
10 A max
Wire Size
22-12 AWG (0.35-2.5 mm sq)
I/O Capacity
16 I/O Terminals
Power Terminals
2 Common Terminals, 2 +Voltage Terminals
Protection Rating
IP20
Termination Type
Screw Clamp (Fused)
Mounting Format
DIN-rail / Panel Mount
Backplane Bus Communication Velocity and Signal Distribution
The 1794-TBNF terminal base establishes the direct backplane interconnect pathway and power distribution layer for 16-point FLEX I/O modules. Designed with integral fusion on the I/O circuits, the terminal arrangement maintains high backplane bus communication velocity across adjacent base units while isolating field-side overcurrent fault conditions. Internal signal paths clamp transient noise to ensure deterministic EtherNet/IP and ControlNet data updates between installed I/O hardware and host automation processors.
Frequently Asked Questions
Q: Does removing the digital or analog module installed on the 1794-TBNF disrupt backplane bus continuity to adjacent units?
A: No. The 1794-TBNF terminal base carries the internal backplane bus pass-through structure, allowing removal and insertion under power (RIUP) of the active I/O module without interrupting communications across the remaining FLEX I/O rail.
Q: What size fuse is supported by the 1794-TBNF terminal base structure?
A: The base accommodates standard 5 x 20 mm blown-fuse indicator fuses rated up to the maximum 10 A continuous current limit of the terminal strip assembly.
Field Installation Guidelines
Snap the terminal base onto a 35 mm DIN rail, ensuring the rear locking latch snaps securely into place against the rail.
Interlock adjacent terminal bases by sliding them laterally until the backplane bus connectors align and seat fully.
Wire field devices to the 16 screw-clamp I/O terminals using 22-12 AWG copper conductors, applying a maximum terminal screw torque of 0.8 Nm (7 lb-in).
Connect incoming system power supply lines to the 2 +Voltage and 2 Common power rail terminals to establish sensor supply buses.
Verify that the DIN-rail grounding shoe maintains clean, paint-free metallic contact with an earth-grounded enclosure rail.
