Overview
The Allen-Bradley 1756-OX8I is a discrete relay output module for the ControlLogix platform, delivering eight isolated channels for precise digital output control in industrial automation systems. This module supports voltage ratings from 5–125 VDC and 10–240 VAC, making it suitable for a wide range of control applications in manufacturing, process control, and machinery automation environments.
Key Features
- 8 Isolated Output Channels – Each channel contains one normally open (N.O.) and one normally closed (N.C.) contact pair for flexible relay control logic
- Multi-Voltage Compatibility – Operates at 5–125 VDC and 10–240 VAC with contact-rated capacities up to 2A @ 125/240 VAC and 0.25A @ 125 VDC
- Point-Level Fault Detection – Individual output status monitoring enables rapid troubleshooting and diagnostic response
- 13 ms Response Time – Fast switching response supports real-time control requirements
- 36-Pin Connector Interface – Tension-clamp spring connections ensure secure, reliable signal integrity
- Integrated Status Indicators – Built-in LED display for output and communication health status visibility
Technical Specifications
- Module Type: Digital Relay Output
- I/O Count: 8 discrete output channels (16 digital contact outputs)
- Output Contacts: 8 N.O. / 8 N.C. individually isolated contacts
- Voltage Rating (Load): 5–125 VDC, 10–240 VAC
- Contact Rating: 2A @ 5–30 VDC, 0.5A @ 48 VDC, 0.25A @ 125 VDC, 2A @ 125/240 VAC
- Input Current: 100 mA (module logic)
- Output Current (per contact): 10A maximum
- Response Time: 13 milliseconds
- Operating Temperature: 0–60°C
- Connector Type: 36-Pin, Tension-Clamp Spring
- Mounting: Chassis (ControlLogix rack)
- Certifications: UL, CSA, CE, RCM, KC, Marine
Typical Applications
The 1756-OX8I is commonly deployed for:
- Discrete output control in motor starters, solenoids, and relay coils
- Safety interlock logic and emergency shutdown circuits
- Equipment enable/disable control in production lines
- Alarm and indicator light switching
- HVAC and facility automation control systems
- Multi-voltage environments requiring isolated contact switching
Compatibility & Replacements
Compatible With
- ControlLogix Chassis (1756 backplane platforms)
- CompactLogix systems via remote I/O adapter
- Studio 5000 Logix Designer programming software
- EtherNet/IP networks for remote monitoring
- Allen-Bradley HMI systems and visualization platforms
Replaces / Drop-In Replacement For
Verify compatibility with your system integrator before ordering. The 1756-OX8I is the current-generation module in the 1756 discrete output family. When replacing similar-generation modules, confirm backplane compatibility and firmware revision requirements.
Works With
- Studio 5000 Logix Designer (all current revisions)
- EtherNet/IP communication protocol
- Rockwell Automation FactoryTalk View HMI
- Allen-Bradley Add-On Profiles (AOP) for 1756 Discrete I/O
- Third-party SCADA systems via standard EtherNet/IP drivers
