Allen-Bradley 1762-OB8 MicroLogix 1200 Solid-State Digital DC Output Module

Description

The Allen-Bradley 1762-OB8 is an 8-point sourcing 24V DC solid-state digital output expansion module designed for the MicroLogix 1200 programmable logic controller system. It expands the discrete output capability of the controller, allowing direct switching of solid-state DC loads in industrial automation, process control, and machine control applications.

The module operates on a 24V DC nominal field supply (5 to 265V AC or 5 to 125V DC operating voltage range) and interfaces directly with the controller through the expansion bus. Featuring transistor-based solid-state outputs, the 1762-OB8 provides high-speed switching capability with maximum signal delays of 0.1 ms for turn-on and 1.0 ms for turn-off. Its rugged open-style enclosure withstands up to 30G operational shock and 5G vibration at 500 Hz, making it suitable for demanding industrial control environments.

Features

• 8 Sourcing Solid-State Outputs: Provides 8 channels of 24V DC sourcing output points for driving DC loads.
• Fast Signal Response: Achieves a maximum turn-on signal delay of 0.1 ms and a turn-off delay of 1.0 ms under resistive loads.
• High Thermal Current Capacity: Supports up to 1.0A continuous current per point and 8.0A per module at 86 degF (30 degC), transitioning to 0.5A per point and 4.0A per module at 131 degF (55 degC).
• Built-In Status Indicators: Equipped with 1 green health indicator and 4 red error indicators for real-time status display and module diagnostics.
• Efficient Power Draw: Draws a maximum bus current of 115 mA at 5V DC (0.575W) from the MicroLogix bus.
• Rugged Mechanical Design: Rated for 30G operational shock and 5G vibration at 500 Hz.

Applications

• Controlling 24V DC solenoids, pilot lights, small DC motor starters, and auxiliary relays.
• High-speed pulse signaling and discrete control loops requiring microsecond-level turn-on response times.
• Discrete load expansion for MicroLogix 1200 controller platforms across packaging, material handling, and automated assembly systems.

Technical Specifications

General

Electrical Specifications

Performance & Environmental

Installation Guidelines

1. Disconnect main power to the MicroLogix controller system and external I/O circuits before installing or removing modules.
2. Mount the module horizontally on a standard 35 mm DIN rail or panel surface, maintaining at least 50 mm (2 in.) of clearance on all sides for convective cooling.
3. Attach the expansion ribbon cable securely to the adjacent controller or 1762 I/O module bus connector, verifying proper bus latch seating.
4. Route 24V DC output power and load wiring separately from AC line power and high-voltage motor conductors to minimize electrical noise.
5. Wire external surge suppression diodes (such as 1N4004) directly across inductive DC loads to protect solid-state output circuits from switching voltage transients.
6. Remove the protective debris shield from the top of the module after panel drilling and wiring are complete to prevent thermal buildup.