Allen Bradley 1747-L552 SLC 5/05 CPU Unit

Description

Product Model: 1747-L552
Product Brand: Allen Bradley (Rockwell Automation)
Product Series: SLC 500 Series

Product Features:

• High-performance processor for SLC 5/05 controllers
• Built-in Ethernet and serial ports for flexible communication
• Supports up to 32K user memory and modular expansion
• Proven reliability in discrete, batch, and continuous control environments

Applications & Industry Context

In the world of industrial automation, the Allen Bradley 1747-L552 stands out as a versatile processor module designed for the SLC 500 control platform. It has long been trusted across industries ranging from automotive and packaging to food processing and water treatment.

In automotive assembly plants, the 1747-L552 often serves as the brain of welding lines and conveyor systems, coordinating hundreds of I/O points with deterministic precision. Food and beverage producers value its reliability for batch processes where consistent timing and recipe handling are critical. Municipal water treatment facilities leverage its robust Ethernet communication to link distributed controllers across pump stations and treatment units.

Field engineers often note its durability. One integrator recalled deploying a 1747-L552 Allen Bradley CPU in a grain handling facility where dust and vibration were constant challenges. Even after years of service, the processor performed without error, proving why the SLC family has such a strong reputation for reliability.

From discrete manufacturing to critical infrastructure, the 1747-L552 remains a dependable choice for automation systems that demand uptime and flexibility.

Technical Features & Benefits

The Allen Bradley 1747-L552 processor module was engineered to deliver both performance and connectivity in a compact form factor.

One of its most recognized features is the built-in Ethernet port, which allows seamless integration into plant networks. This simplifies programming, monitoring, and data exchange with higher-level systems such as SCADA or MES platforms. Alongside Ethernet, the unit includes an RS-232 serial port, giving it flexibility for legacy devices and point-to-point communications.

The 1747-L552 provides up to 32K of user memory, supporting complex programs and data handling. For applications requiring fast response, its instruction execution time is significantly improved compared to earlier SLC processors. This makes it suitable for time-sensitive control sequences such as high-speed sorting or synchronized assembly tasks.

Engineers appreciate the modularity of the SLC 500 series. The 1747-L552 CPU can be paired with various I/O, specialty, and communication modules, allowing users to build a control solution tailored to their process.

Diagnostics and status indicators make troubleshooting straightforward. When combined with RSLogix 500 software, users gain an intuitive interface for programming, simulation, and real-time monitoring.

The result is a balance of performance, flexibility, and long-term reliability — reasons why the 1747-L552 remains a mainstay in many plants even as newer controllers enter the market.

Technical Specifications Table

Product Role & System Fit

The 1747-L552 acts as the central processor of the SLC 5/05 controller, coordinating logic execution, communications, and I/O management. Within the modular SLC 500 platform, it sits in the main processor slot, working alongside power supplies, chassis, and I/O cards to create a complete automation solution.

Its Ethernet capability makes it particularly valuable for plants standardizing on industrial networking. This allows the CPU to serve as both a logic solver and a gateway to higher-level systems. For legacy equipment, the RS-232 port ensures backward compatibility, extending the life of existing investments.

Because of its flexibility, the Allen Bradley 1747-L552 fits equally well in standalone machines and plant-wide distributed control systems. It provides the scalability to start with a small application and expand as process needs grow, making it a practical option for both OEMs and end users.

Installation & Maintenance Insights

Installing the Allen Bradley 1747-L552 CPU is a straightforward process, but following best practices ensures reliability. Engineers must ensure the module is fully seated in the processor slot of the SLC chassis, with secure grounding and power supply connections. Proper ventilation is also critical, as tightly packed panels can increase thermal stress.

Before commissioning, users should verify firmware versions and confirm compatibility with programming software. When integrating with plant networks, assigning static IP addresses and using managed Ethernet switches improves stability and diagnostic visibility.

From a maintenance perspective, the 1747-L552 has a strong reputation for longevity. Still, periodic backups of logic programs and parameter files are essential to minimize recovery time in the event of a failure. Engineers also recommend keeping at least one spare CPU in stock, especially for continuous-process industries where downtime is costly.

Because the module is not hot-swappable, replacement requires powering down the chassis. Planning scheduled maintenance windows helps avoid unnecessary interruptions.

Related Models

• 1747-L551 Allen Bradley SLC 5/05 Processor – 16K memory version
• 1747-L553 Allen Bradley SLC 5/05 Processor – higher memory variant
• 1747-L532 Allen Bradley SLC 5/03 Processor – lower model with DH-485 communication
• 1747-L541 Allen Bradley SLC 5/04 Processor – with DH+ communication
• 1747-L524 Allen Bradley SLC 5/02 Processor – earlier generation CPU
• 1747-L531 Allen Bradley SLC 5/03 Processor – with limited I/O support
• 1747-ASB Allen Bradley Remote I/O Adapter – allows SLC chassis expansion