Allen-Bradley 1794-TB3 Flex I/O Terminal Base Unit
The Allen-Bradley 1794-TB3, also cataloged as the 1794-TB3 Terminal Base Unit, operates as a dedicated hardware component for field signal termination and backplane power routing within Flex I/O 1794 system architectures.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 1794-TB3 |
| Brand | Allen-Bradley |
| Origin | USA |
| Weight | 0.63 lbs (0.28 kg) |
| Dimensions | Standard Flex I/O Terminal Base Footprint |
| Operating Temp | -20 to 70 deg C |
| Storage Temp | -40 to 85 deg C |
| Power Consumption | 640 mA at 5 VDC (FLEXBus current) |
| V/COM Terminal Supply Voltage | 125 VAC/DC max |
| V/COM Terminal Frequency | 50/60 Hz |
| V/COM Terminal Current | 10 A max |
| Continuous Isolation Voltage | 125 V continuous |
| Termination Type | Cage-Clamp |
| Terminal Screw Torque | 0.56 to 0.79 Nm |
| Enclosure Type | Open-Style (None) |
Deterministic Network Communication & I/O Density
The 1794-TB3 terminal base unit establishes the electrical wiring foundation and high-density I/O routing matrix for standard 3-wire Flex I/O modules, accelerating I/O density scaling across distributed control networks. Internal bus connectors transmit 5 VDC power up to 640 mA and control signals deterministically to mounted modules without signal loss, while offering full firmware flash compatibility across standard 1794 series network adapters. Integrated channel isolation and continuous 125 V rating ensure high backplane bus communication velocity and signal integrity during fast switching events.
Frequently Asked Questions
Q: What torque rating should be applied to the cage-clamp terminal screws on the 1794-TB3?
A: Terminal screws must be torqued to between 0.56 and 0.79 Nm (5 to 7 lb-in) to ensure stable electrical connections and prevent conductor damage.
Q: Can 1794 series I/O modules be replaced on the 1794-TB3 while power is applied to the backplane?
A: Yes. The 1794-TB3 supports Removal and Insertion Under Power (RIUP), allowing field replacement of mounted modules without disturbing wiring or disrupting backplane bus communications to adjacent units.
Q: What is the maximum voltage and current capacity of the V/COM terminals?
A: The V/COM terminals are rated for up to 125 VAC/DC at 50/60 Hz with a maximum continuous current capacity of 10 A.
Field Installation Guidelines
- Mount the open-style 1794-TB3 unit inside a protective panel enclosure on a standard 35 mm DIN rail.
- Interconnect adjacent terminal base units using the integrated side-locking keys to ensure proper backplane connector engagement.
- Strip field wiring conductors to specified lengths and secure them into the cage-clamp terminals, applying 0.56 to 0.79 Nm of torque to the screws.
- Connect main power and common supply conductors to the designated V/COM terminals to provide distributed power across mounted I/O modules.
- Ensure panel enclosure ventilation maintains ambient temperatures within the specified -20 to 70 deg C operating envelope.
Allen-Bradley 1794-TB3 Flex I/O Terminal Base Unit
Allen-Bradley 1794-TB3 Flex I/O Terminal Base Unit
The Allen-Bradley 1794-TB3, also cataloged as the 1794-TB3 Terminal Base Unit, operates as a dedicated hardware component for field signal termination and backplane power routing within Flex I/O 1794 system architectures.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 1794-TB3 |
| Brand | Allen-Bradley |
| Origin | USA |
| Weight | 0.63 lbs (0.28 kg) |
| Dimensions | Standard Flex I/O Terminal Base Footprint |
| Operating Temp | -20 to 70 deg C |
| Storage Temp | -40 to 85 deg C |
| Power Consumption | 640 mA at 5 VDC (FLEXBus current) |
| V/COM Terminal Supply Voltage | 125 VAC/DC max |
| V/COM Terminal Frequency | 50/60 Hz |
| V/COM Terminal Current | 10 A max |
| Continuous Isolation Voltage | 125 V continuous |
| Termination Type | Cage-Clamp |
| Terminal Screw Torque | 0.56 to 0.79 Nm |
| Enclosure Type | Open-Style (None) |
Deterministic Network Communication & I/O Density
The 1794-TB3 terminal base unit establishes the electrical wiring foundation and high-density I/O routing matrix for standard 3-wire Flex I/O modules, accelerating I/O density scaling across distributed control networks. Internal bus connectors transmit 5 VDC power up to 640 mA and control signals deterministically to mounted modules without signal loss, while offering full firmware flash compatibility across standard 1794 series network adapters. Integrated channel isolation and continuous 125 V rating ensure high backplane bus communication velocity and signal integrity during fast switching events.
Frequently Asked Questions
Q: What torque rating should be applied to the cage-clamp terminal screws on the 1794-TB3?
A: Terminal screws must be torqued to between 0.56 and 0.79 Nm (5 to 7 lb-in) to ensure stable electrical connections and prevent conductor damage.
Q: Can 1794 series I/O modules be replaced on the 1794-TB3 while power is applied to the backplane?
A: Yes. The 1794-TB3 supports Removal and Insertion Under Power (RIUP), allowing field replacement of mounted modules without disturbing wiring or disrupting backplane bus communications to adjacent units.
Q: What is the maximum voltage and current capacity of the V/COM terminals?
A: The V/COM terminals are rated for up to 125 VAC/DC at 50/60 Hz with a maximum continuous current capacity of 10 A.
Field Installation Guidelines
- Mount the open-style 1794-TB3 unit inside a protective panel enclosure on a standard 35 mm DIN rail.
- Interconnect adjacent terminal base units using the integrated side-locking keys to ensure proper backplane connector engagement.
- Strip field wiring conductors to specified lengths and secure them into the cage-clamp terminals, applying 0.56 to 0.79 Nm of torque to the screws.
- Connect main power and common supply conductors to the designated V/COM terminals to provide distributed power across mounted I/O modules.
- Ensure panel enclosure ventilation maintains ambient temperatures within the specified -20 to 70 deg C operating envelope.
