1756-OG16 Allen-Bradley ControlLogix 16-Point TTL Output Module

Product Overview

The 1756-OG16 is a specialized 16-channel transistor-transistor logic (TTL) digital output module engineered for the Allen-Bradley ControlLogix automation platform. Designed to interface directly with low-voltage logic devices, this module delivers precise 5V DC true/low outputs across a 4.5 to 5.5 VDC operational window. Control system engineers rely on the 1756-OG16 to achieve lightning-fast signal switching and reliable logic-level integration within high-performance industrial control environments.

Technical Specifications

• Brand: Allen-Bradley / Rockwell Automation
• Series: ControlLogix Platform
• Part Number: 1756-OG16
• Product Type: Digital TTL DC Output Module
• Number of Outputs: 16-Point Low/True TTL Outputs
• Nominal Output Voltage: 5 VDC TTL Source
• Operating Voltage Range: 4.5 to 5.5 VDC
• Maximum Output Current Rating: 24 mA per point; 384 mA total per module at 60 °C
• Backplane Current Draw: 210 mA at 5.1 VDC; 2 mA at 24 VDC (1.12 W total power)
• Power Dissipation: 1.5 Watts maximum at 60 °C (5.2 BTU/hr thermal dissipation)
• Signal Delay Time: 450 µs (Off-to-On); 700 µs (On-to-Off) load-dependent
• Off-State Leakage Current: 0.1 mA maximum per point
• Compatible Terminal Blocks: 1756-TBNH or 1756-TBSH Removable Terminal Blocks (RTB)

Installation & Integration Guide

• Chassis Assignment: Install the 1756-OG16 module into any available single slot within a standard ControlLogix local chassis or distributed I/O rack.
• Wiring & Termination: Connect field-side TTL circuits securely using compatible 1756-TBNH or 1756-TBSH terminal blocks to ensure stable signal propagation.
• Power Budgeting: Account for the module's backplane current requirements (210 mA @ 5.1V DC) when calculating total power supply loading for your ControlLogix rack.
• Environmental Compliance: Verify that cabinet operating temperatures remain between 0 and 60 °C with relative humidity kept under 95% non-condensing.

Commissioning & Maintenance Ease

• Rapid Response Monitoring: Leverage the module's microsecond-level switching speeds (sub-millisecond delay times) for high-frequency pulse and logic-level verification.
• Fault Isolation: Monitor individual channel output status via controller diagnostic tags to quickly identify load-side shorts or open circuits.
• Hot-Swap Capability: Utilize the Removable Terminal Block (RTB) design to replace faulty modules swiftly without disrupting field wiring or shutting down the entire panel.

Compatibility & Certifications

• Controller Compatibility: Fully compatible with Allen-Bradley ControlLogix central processing units and Logix Designer programming environments.
• Industrial Certifications: Certified under CE and UL standards, featuring CISPR 11 Class A emission compliance and a T5 temperature rating.
• Rugged Durability: Built to withstand harsh industrial conditions with a 30G operational shock rating and 2.0G vibration resistance (10-500 Hz).

Packing List & Warranty Terms

• Packing List: One (1) 1756-OG16 TTL Output Module, protective anti-static packaging casing, and hardware compliance documentation sheet.
• Warranty Terms: Fully backed by a comprehensive 12-month warranty covering structural integrity and operational performance from the date of purchase.

Shipping & Logistics

• Courier Network: Secure, expedited global shipping handled through trusted carriers including FedEx, UPS, and DHL.
• Fulfillment Window: Orders are verified, securely packed, and dispatched within 24-48 hours to minimize unexpected plant downtime.

Typical Application Scenes

• Semiconductor Fabrication: Interfacing with specialized 5V logic controllers, microprocessors, and custom TTL-driven instrumentation boards.
• Data Acquisition Test Rigs: Driving high-speed digital pulse trains and triggering precision laboratory measurement hardware.
• Specialized OEM Machinery: Managing low-voltage digital control signals within compact, vibration-resistant automation enclosures.

Global PLC Spare HUB Insight & Field Experience

When deploying 5V TTL output cards like the 1756-OG16, signal degradation over long wire runs is a common hurdle due to the low voltage amplitude. Based on field installation experience, our engineering team strongly recommends keeping field cable runs short (under 3 meters), using tightly twisted-pair shielded cabling, and ensuring clean ground separation from high-voltage AC lines to prevent voltage drops and false switching logic.

Frequently Asked Questions

What is the primary difference between standard 24V DC outputs and the TTL outputs on the 1756-OG16?

The 1756-OG16 operates specifically on a 5V DC logic level designed for transistor-transistor logic devices, whereas standard cards typically switch higher 24V or 120V field voltages.

Can the 1756-OG16 drive heavy industrial actuators or solenoids directly?

No, because each point is rated for a maximum current of 24 mA at 5V DC, this module is strictly intended for driving low-power logic inputs, LEDs, or intermediate TTL interface relays.

What terminal blocks are compatible with this module?

The module utilizes standard Allen-Bradley Removable Terminal Blocks, specifically the 1756-TBNH or 1756-TBSH housing options.

How do I handle maintenance replacement without disturbing cabinet wiring?

The Removable Terminal Block (RTB) snaps off the front of the module, allowing you to unclip and replace the hardware chassis unit without disconnecting individual field wires.

What selection parameters are critical when sourcing a replacement TTL output card?

Always verify your control system's logic voltage requirements (5V TTL vs. 24V DC), total module current limits (384 mA max), and available backplane power slot capacity before ordering.

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