Product Details
Product Overview
The Allen-Bradley 1756-A7K provides the structural and electrical backbone for mid-sized ControlLogix automation systems. This 7-slot chassis facilitates high-speed data communication via its passive backplane, linking processors, I/O modules, and communication bridges. We supply this unit as 100% Brand New and Original, featuring the "K" suffix for factory-applied conformal coating. This chemical-resistant layer protects internal circuitry from corrosive gases, moisture, and airborne contaminants, making it the industry standard for chemical processing, oil and gas, and wastewater treatment applications.
Technical Specifications
| Parameter | Specification Details |
| Number of Slots | 7 Slots |
| Backplane Current (Max @ 5.1V DC) | 15 A (Chassis) / 6 A (Slot) |
| Backplane Current (Max @ 3.3V DC) | 4 A (Chassis) / 4 A (Slot) |
| Backplane Current (Max @ 24V DC) | 2.8 A (Chassis) / 2.8 A (Slot) |
| Power Dissipation (Max) | 4.5 Watts |
| Operating Temperature Code | T5 (North American and IEC) |
| Mounting Orientation | Horizontal Only |
| Protective Earth Ground Wire | 2.1 mm² (14 AWG) Copper Wire |
| Weight | 1.10 kg (2.4 lbs) |
Engineering Advantages
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Superior Environmental Hardening: The 1756-A7K utilizes a specialized conformal coating to shield sensitive copper traces. This prevents dendritic growth and corrosion in environments categorized by ISA G3 (Harsh) standards, extending the hardware lifecycle significantly compared to standard non-coated versions.
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High-Capacity Power Distribution: The backplane delivers 15 Amps at 5.1V DC. This robust power overhead supports high-density I/O configurations and multiple high-performance processors within a single rack without the risk of voltage sags or thermal instability.
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Streamlined Earthing Protocol: The chassis design includes dedicated points for Functional Earth and Protective Earth. Utilizing 8 AWG and 14 AWG copper wire respectively ensures effective dissipation of electromagnetic interference (EMI), maintaining signal integrity for high-speed motion and analog data.
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Passive Backplane Reliability: By eliminating active electronic components on the backplane itself, the 1756-A7K reduces potential failure points. This design ensures that the chassis remains a transparent, high-speed highway for data exchange across all 7 slots.
FAQs
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What is the difference between the 1756-A7 and the 1756-A7K?
The 1756-A7K includes a factory-applied conformal coating ("K" suffix). While they share the same physical dimensions and slot count, the 1756-A7K provides essential protection against corrosive environments and humidity that would otherwise cause standard boards to fail.
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Can I mount the 1756-A7K vertically to save cabinet space?
No. Technical guidelines mandate horizontal mounting only. Horizontal orientation ensures proper heat convection from the installed power supply and modules, preventing hotspots that could trigger thermal shutdowns of your processors.
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Does the chassis include a power supply?
The chassis functions as a housing and backplane only. You must purchase a compatible 1756 power supply (such as the 1756-PA72K or PB72K) separately. We recommend using conformal-coated "K" version power supplies to match the environmental protection of the 1756-A7K.
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Is this a refurbished or used surplus unit?
We guarantee this product is 100% Brand New and Original. It arrives in the original manufacturer's packaging with the factory seal intact, ensuring you receive the full operational lifespan and performance expected from Allen-Bradley hardware.
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
- Worldwide Shipping: We ship via USPS, UPS, FedEx, and DHL. Delivery times vary by country and may be subject to customs or import fees.
- Support & Contact: Technical and warranty assistance is available anytime. Contact us here: Contact.
- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.
Tech & Buying Guide
Why Programmable Logic Controllers Drop into Stop Mode: An Expert Analysis
Industrial automation systems rely heavily on Programmable Logic Controllers (PLCs) to maintain uninterrupted production. When a PLC unexpectedly shifts from Run to Stop mode, whole manufacturing lines stall.
As control systems evolve across modern factory automation, understanding the root causes of these interruptions helps engineers minimize costly downtime. This technical guide breaks down why PLCs trip into Stop mode and provides practical strategies to mitigate system faults.
Understanding Root Causes of Unplanned PLC Stop Mode in Industrial Automation
Modern Programmable Logic Controllers manage execution through distinct operational states: Run, Stop, Start-Up, and Hold. During power-up, a controller initializes memory registers within Stop mode before briefly transitioning to Start-Up mode. During this phase, internal self-diagnostics evaluate system integrity across hardware and user programs. If the controller detects no critical faults, it enters Run mode to execute the control program continuously. However, any severe system anomaly forces the CPU back into Stop mode immediately to prevent erratic machine behavior across the plant floor.
Human-Machine Interface Design: Essential Guide to HMI Selection, Visualization, and Control System Integration
Human-Machine Interfaces (HMIs) serve as the primary operational window into complex industrial automation systems. Modern HMIs convert raw machine data into clear graphical displays, enabling operators to oversee entire manufacturing processes in real time. Instead of relying on physical control panels full of hardwired switches, engineers program interactive screens using intuitive graphics, dynamic color coding, and responsive touch interfaces. Over my 15 years in control systems engineering, I have observed HMIs transform from basic display screens into sophisticated command centers that drive operational efficiency across DCS and PLC environments.