Product Details
Overview
The 1756-L55M12 (1756-L55M12) is a high-performance Logix5555 processor designed for the Allen-Bradley ControlLogix platform. This module is engineered to handle complex control engine requirements, providing a multitasking operating environment that supports multiple programming languages including Ladder Logic, Structured Text, and Function Block Diagrams. With 750 Kilobytes of available user memory, it offers a reliable solution for medium-scale industrial applications requiring precise I/O management and fast logic execution.
Technical Specifications and Performance Data
The 1756-L55M12 (1756-L55M12) integrates directly into any slot of a ControlLogix chassis, leveraging the high-speed backplane for data distribution and peer-to-peer communication.
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Memory Configuration: 750 Kilobytes of User RAM (Non-volatile storage available via optional CompactFlash on newer Logix series, but this legacy unit utilizes battery-backed RAM).
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I/O Capacity: Supports a maximum of 128,000 total I/O points.
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Analog Scaling: Capable of managing 4,000 Analog Inputs and 2,000 Analog Outputs.
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Logic Execution Time: Typical program scan time of 0.08 milliseconds (specific to simple logic rungs).
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Current Draw: 1.23 Amps at 5.1V DC; 14 milliamps at 24V DC.
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Thermal Dissipation: Approximately 19.1 BTU per hour.
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Communication Options: Compatible with EtherNet/IP, ControlNet, DeviceNet, and Data Highway Plus through respective communication modules.
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Battery Backup: Compatible with 1756-BA1 or the 1756-BATM externally mounted battery assembly for extended program retention.
Environmental and Physical Standards
The hardware is designed for continuous operation in industrial environments, adhering to strict vibration and temperature tolerances.
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Operational Temperature: 0 to 60 degrees Celsius (32 to 140 degrees Fahrenheit).
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Storage Temperature: -40 to 85 degrees Celsius (-40 to 185 degrees Fahrenheit).
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Humidity: 5% to 95% non-condensing.
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Vibration Resistance: 2.0g @ 10 to 500 Hertz.
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Weight: 0.37 kg (0.81 lbs).
Common Technical Inquiries
How is the user memory partitioned in the 1756-L55M12?The 750KB of memory is shared between data storage and the application code. Unlike legacy PLC-5 systems, the ControlLogix platform allocates memory dynamically based on the tag-based database structure.
Which programming software is required for this module?The 1756-L55M12 (1756-L55M12) is typically programmed using RSLogix 5000 software. The firmware revision of the processor must match the major version of the software project.
What is the purpose of the 1756-BATM?While the 1756-BA1 is a standard internal battery, the 1756-BATM is an optional battery module used for applications where the controller is powered down for long periods, providing significantly higher mAh capacity to preserve memory.
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
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.
Understanding Safety Relays in Industrial Automation: Architecture, Operation, and Functional Safety
Standard electromechanical relays provide basic electrical isolation between low-voltage control circuits and high-power output loads. A traditional switching relay features a magnetic coil driving mechanical Common (COM), Normally-Open (NO), and Normally-Closed (NC) contacts. However, standard relays pose severe functional risks when deployed in critical safety interlock circuits. High current inrush or mechanical wear can weld contacts together permanently. If contact welding occurs in an emergency stop circuit, pressing the button fails to halt hazardous machinery movements. Consequently, global functional safety standards prohibit standard relays for critical machine guarding functions.