1756-OB8 | Allen Bradley | ControlLogix Digital DC Output Module

Product Overview

The Allen Bradley 1756-OB8 provides high-current discrete control within the ControlLogix ecosystem. This module features eight independent sourcing outputs, delivering 24V DC power directly to field devices. As a 100% Brand New and Original unit, it serves as a robust interface for driving heavy-duty DC loads such as large solenoids, motor starters, and hydraulic valves. Its high amperage rating makes it the primary choice for applications requiring more power than standard high-density I/O modules can provide.

Technical Specifications

The 1756-OB8 utilizes a sourcing architecture to switch power to the load with the following performance ratings:

Engineering Advantages

• High-Current Drive Capability: Each of the 8 channels supports up to 2 Amps. This eliminates the need for interposing relays when controlling larger DC actuators, reducing the total component count in the control cabinet.

• Sourcing Output Safety: The sourcing (current sourcing) design switches the positive side of the DC circuit. This configuration prevents accidental machine starts if a wire shorts to the ground, aligning with international safety standards for industrial machinery.

• Deterministic Logic Execution: Integrated electronic fusing and high-speed switching circuits ensure the module responds to processor commands with minimal latency, maintaining tight synchronization for motion and process control loops.

• Simplified Maintenance: The module utilizes a Removable Terminal Block (RTB), allowing technicians to replace the hardware without disconnecting individual field wires, which significantly minimizes system downtime.

FAQs

• Does this module require a specific Removable Terminal Block (RTB)?

  Yes. You must use a 1756-TBNH or 1756-TBSH (spring clamp) terminal block. The RTB does not ship with the module and requires a separate order to complete the installation.

• Can I parallel the outputs to achieve a higher current rating?

  The hardware does not support paralleling outputs to increase current capacity for a single load. Each point operates independently with its own 2A current limit to protect the internal circuitry.

• How does the 1756-OB8 handle short circuits in the field?

  The module features electronic protection that detects over-current conditions. It shuts down the affected channel to prevent hardware damage, while providing diagnostic feedback to the ControlLogix processor.

• Is this a factory-sealed, new-in-box unit?

  Absolutely. We guarantee this 1756-OB8 is 100% Brand New original stock. It arrives in factory-sealed Allen Bradley packaging with original security labels intact.