Product Overview

The Allen-Bradley 1756-L55 (Logix5555) serves as the powerhouse for mid-to-large scale automation within the ControlLogix platform. This processor executes complex control engine tasks, managing high-speed I/O and communication across EtherNet/IP, ControlNet, and DeviceNet networks. By utilizing a multi-tasking operating system, it optimizes scan times for both discrete and process applications. We offer this unit as 100% Brand New and Original, typically featuring the M13 memory expansion to ensure robust program storage and data logging capabilities right out of the box.

Technical Specifications

Engineering Advantages

• Scalable Memory Architecture: The 1756-L55 supports modular memory expansion. This allows engineers to scale the controller’s capacity to match increasing code complexity without replacing the entire CPU, significantly protecting your hardware investment as the plant grows.

• Superior Noise & RF Immunity: Built for harsh electromagnetic environments, this processor withstands conducted RF interference up to 10V rms. This high level of immunity prevents logic errors and unexpected shutdowns caused by proximity to variable frequency drives (VFDs) and high-power radio equipment.

• Efficient Thermal Management: Dissipating only 19.4 BTU/hr, the 1756-L55 maintains a low thermal footprint. This efficiency reduces the cooling requirements of your control cabinet, extending the lifespan of adjacent I/O and communication modules.

• Broad Network Integration: The Logix5555 architecture bridges disparate networks seamlessly. By adding 1756-series communication modules, the L55 controller coordinates data between factory-floor DeviceNet sensors and enterprise-level EtherNet/IP systems simultaneously.

FAQs

What battery does the 1756-L55 require for data retention?

The 1756-L55 uses the 1756-BA1 lithium battery. This battery maintains the user program and tag data in the internal SRAM during power-down cycles. We recommend replacing the battery every 1–2 years as part of preventative maintenance to avoid program loss.

Can the 1756-L55 handle Motion Control?

Yes. When paired with 1756-series SERCOS or analog motion modules, the 1756-L55 executes complex motion instructions. It handles geared moves, cams, and coordinated linear/circular interpolation, making it suitable for packaging and assembly machinery.

Is the 1756-L55 compatible with newer Studio 5000 software?

The 1756-L55 is an established "Logix5555" controller. It typically supports RSLogix 5000 software up to Version 16. For systems requiring higher firmware versions (v17–v35+), we recommend upgrading to the 1756-L7 or L8 series processors. However, the L55 remains the standard for maintaining and expanding thousands of existing operational lines worldwide.

How do I install the memory expansion card?

The memory card (such as the M13) installs directly into the side of the 1756-L55 processor. You must perform this installation while the module is removed from the chassis or with the chassis power turned off to prevent damage to the sensitive CMOS circuitry.