Allen-Bradley 1746-OBP8 SLC 500 Digital DC Output Module 8-Channel

Technical Specifications Breakdown

Key parameters for the 1746-OBP8 are listed below for quick reference:

Industry Applications

Automotive Assembly Lines

In automotive body shops, high-speed pick-and-place and welding fixtures require fast, reliable DC outputs. The 1746-OBP8 delivers a 1.0 ms turn-on and 2.0 ms turn-off signal delay, enabling precise timing for solenoid valves and pilot lamps. Its 2.0A per output capacity handles multiple small actuators without derating, reducing the need for additional interposing relays.

Packaging Machinery

Packaging lines often involve continuous cycling of pneumatic cylinders and motorized actuators. The module's 8.0A total module current at 60°C supports simultaneous operation of several outputs, while the sourcing configuration simplifies wiring with common 24V DC sensors and controllers. The fast turn-off characteristic minimizes inductive load arcing, extending contact life.

Material Handling Systems

Conveyor diverters, sortation gates, and alarm annunciators benefit from the module's high-current solid-state outputs. The 1746-OBP8 can be integrated into SLC 500 fixed or modular hardware, and its open-type enclosure mounts directly to the chassis, saving panel space. For AC loads, interposing relays with 24V DC coils provide isolation and voltage matching.

Installation & Setup Guidance

Mount the 1746-OBP8 in any available slot of the SLC 500 chassis, ensuring backplane power is supplied. Use 14 AWG (2 mm²) maximum signal wires for output connections. Connect an external 24V DC power source to the module's output power terminals; the module itself does not generate output power. For sourcing outputs, the load connects between the output point and the common (DC return). Verify that the total module current does not exceed 8.0A at 0-60°C ambient temperature. The module occupies one slot and draws 0.135A from the 5V backplane.

Maintenance & Reliability

Periodically inspect the module for dust accumulation and ensure ambient temperature remains within 0-60°C. The non-condensing humidity range of 5-95% covers most industrial environments. The module withstands 30g operating shock and vibration up to 2.5g at 57-2000 Hz. No electronic protection is built in, so external fusing or circuit breakers are recommended for each output group. The LED indicators (e-fuse LEDs) provide visual status of each output.

High-Current Digital Output Control for SLC 500 Systems

Industrial automation engineers often face the challenge of controlling multiple high-current DC loads with limited panel space and tight timing requirements. This unit provides eight sourcing outputs, each capable of handling 2.0A continuously at 60°C, making it suitable for energizing solenoids, pilot lamps, alarms, and motorized actuators without the need for external interposing relays in many 24V DC applications.

Compatibility & Integration

This module is compatible with all SLC 500 processors, including stand-alone, expanded, and remote I/O topologies. It works with both fixed and modular hardware styles. The 1746-OBP8 can drive 24V DC loads directly; for AC loads, use interposing relays with 24V DC coils. The module does not include communication protocols—it is a simple output module controlled by the backplane.

Selection Guide & Purchasing Advice

When selecting a digital output module for high-current DC applications, consider the number of outputs, per-point current, and sourcing vs. sinking configuration. AutoDCSTech stocks this module and can advise on lifecycle status and availability. Please verify current lifecycle status with AutoDCSTech before ordering.

Troubleshooting & Common Issues

If an output fails to energize, check the external 24V DC power supply and the backplane connection. Verify that the load current does not exceed 2.0A per point and that total module current stays under 8.0A. If the LED indicator is off, the output may be in an off state or the internal fuse may have opened. The module has no electronic protection, so overcurrent conditions can damage the output. Inspect wiring for shorts and ensure correct polarity for sourcing outputs.