1756-OB16DK Allen-Bradley ControlLogix 24VDC 16-Pt Diagnostic Output Module

1756-OB16DK Allen-Bradley ControlLogix Diagnostic Output Module Overview

The 1756-OB16DK stands as a high-integrity 16-point diagnostic digital output module within the ControlLogix ecosystem. Engineered for the ControlLogix 5580 controller range, this unit provides precise 24V DC sourcing capabilities. The 1756-OB16DK distinguishes itself with integrated conformal coating, making it an essential choice for hazardous locations requiring T4A temperature compliance. We recommend downloading the official 1756-OB16DK technical data sheet for specific pulse-test and fault-latching configurations.

Technical Specifications

• Manufacturer: Rockwell Automation / Allen-Bradley
• Model: 1756-OB16DK
• Series: ControlLogix
• Module Type: Diagnostic DC Output (Sourcing)
• Output Density: 16-Points (8 Points per Group)
• Operating Voltage: 19.2–30V DC (24V Nominal)
• Peak Current (Point): 2 Amps @ 30°C
• Aggregate Current: 8 Amps @ 30°C / 4 Amps @ 60°C
• Backplane Draw: 250mA @ 5.1V / 140mA @ 24V
• Thermal Dissipation: 11.25 BTU/hr
• Vibration/Shock: 2 G @ 10-500Hz / 30 G Operating Shock
• Environmental: Conformal Coating (K-Suffix Protection)

Global PLC Spare HUB's Insight

The 1756-OB16DK is more than a standard switch; it is a critical diagnostic tool. The "D" suffix indicates advanced internal logic that detects "No Load" conditions and short circuits even when the output is in the "Off" state. For engineers, the 1756-OB16DK significantly reduces Mean Time to Repair (MTTR) by pinpointing field-side wiring faults through software tags. The "K" version is mandatory for environments with high sulfur or salt spray, ensuring internal circuitry remains insulated from atmospheric contaminants.

Diagnostic Capabilities & Applications

• Fault Detection: Provides electronic short-circuit protection and individual point-level monitoring.
• Device Compatibility: Optimized for solenoid valves, actuators, and motor starters.
• Typical Scenarios: Chemical processing plants, wastewater facilities, and offshore platforms.
• Maintenance: Compatible with 1756-TBCH and 1756-TBS6H Removable Terminal Blocks.

Logistics & Warranty

• Dispatch Time: Orders for the 1756-OB16DK ship within 24-48 hours.
• Express Delivery: Global shipping via FedEx, UPS, and DHL.
• Warranty: Full 12-month technical warranty included.
• Package List: One 1756-OB16DK Module in original protective industrial packaging.

Frequently Asked Questions (FAQ)

• What is the specific advantage of the "K" suffix on this 1756-OB16DK module?

The "K" denotes a conformal coating. This provides a chemical-resistant layer over the PCB, preventing silver whiskers and corrosion in Class G3 environments.

• Can the 1756-OB16DK detect a broken wire in the field?

Yes. As a diagnostic module, it detects "Open Wire" or "No Load" conditions even when the output is off, if the feature is enabled in the profile.

• How does thermal derating affect the output capacity at high temperatures?

At 30°C, the module supports 8 Amps. At 60°C, the 1756-OB16DK must be derated to 4 Amps total to prevent overheating.

• Does this module support "Per-Point" electronic fusing?

It features electronic short-circuit protection. It acts like a fuse to protect the module but is self-resetting once the fault is cleared via software.

• What should I consider when selecting a terminal block for the 1756-OB16DK?

Use 36-pin terminal blocks like 1756-TBCH or 1756-TBS6H. Standard 20-pin blocks are physically incompatible.

Purchasing & Selection Guide

• Always match the 1756-OB16DK with a chassis rated for the same temperature code (T4A).
• If your application involves corrosive gases, the 1756-OB16DK offers superior long-term hardware insurance over standard versions.
• Verify your power supply capacity for the 24V backplane requirements (140mA) to ensure system stability.

Tags

PDF

• Download PDF