Product Overview

The Allen‑Bradley 1747‑L552 is a high‑memory SLC 5/05 processor inside the Rockwell SLC 500 control family. As the mid‑range Ethernet-enabled CPU of the SLC 5/05 lineup, it delivers the same EtherNet/IP networking advantages as the 1747‑L551 but doubles the available user memory to support larger ladder logic programs, extensive data tables, recipe storage and heavier messaging workloads. It is a preferred drop‑in upgrade for existing SLC racks when the 16K memory of the L551 becomes insufficient. This controller is widely sourced by maintenance teams, system integrators and machine owners for legacy line retrofits, spare replacement and plant standardization. It requires the 1747‑BA lithium backup battery to preserve RAM data and real‑time clock after chassis power loss.

Key Specifications

• Part Number: 1747‑L552
• Manufacturer: Allen‑Bradley (Rockwell Automation)
• Series: SLC 500, SLC 5/05 Processor
• User Memory: 32K words (28K available for program and data storage)
• Communication Ports: Integrated 10 Mbps 10Base-T Ethernet RJ45 port, RS‑232 serial port
• Supported Protocols: EtherNet/IP, TCP/IP, DH‑485, DF1 Full/Half Duplex, ASCII, SNMP, BOOTP
• Maximum I/O Capacity: Up to 4096 digital inputs and 4096 digital outputs; supports up to 480 analog points
• Typical Scan Time: 0.9 ms per K-word of ladder logic
• Backplane Compatibility: Standard SLC 500 rack/chassis
• Programming Software: RSLogix 500
• Operating Temperature: 0 °C to +60 °C
• Storage Temperature: -40 °C to +85 °C
• Vibration & Shock: Designed to meet industrial vibration and shock standards for factory floor deployment
• Mounting: Rack mount, direct slot installation in SLC chassis
• Backup Battery: 1747‑BA (sold separately)
• End of Life: Original production discontinued, supplied as tested surplus / refurbished spare

Communication Features

The 1747‑L552 combines Ethernet and serial connectivity for flexible plant networking. The onboard 10Base-T Ethernet channel enables program upload/download, online editing, peer‑to‑peer messaging between SLC 5/05 controllers, communication with PanelView HMIs, SCADA systems, drives and other EtherNet/IP devices without external communication adapters. It supports BOOTP for IP assignment and SNMP for basic network monitoring. The RS‑232 channel operates in DF1 or ASCII mode for local programming, modem remote access, barcode scanners, weighing instruments, serial printers and legacy serial equipment. It also supports channel passthrough, allowing technicians to access the serial network over the Ethernet connection for convenient remote troubleshooting.

Application Scenarios

This processor is selected for SLC installations that demand more memory than the 1747‑L551 can offer. Common applications include multi‑recipe packaging machinery, large conveyor sorting systems, batch process skids, water and wastewater control, printing presses, metal processing lines and custom automated machines with complex sequencing and substantial data logging requirements. It is heavily used in scheduled shutdown replacements, emergency CPU spares and upgrade projects where engineers keep the existing SLC rack, I/O wiring and field devices intact while swapping to a higher‑memory controller to avoid full platform migration.

Compatibility

The 1747‑L552 fits all standard SLC 500 chassis and works with the complete portfolio of SLC discrete I/O, analog modules, high‑speed counters, thermocouple/RTD modules, power supplies and rack accessories. It communicates seamlessly with other SLC 5/01, 5/02, 5/03, 5/04 and 5/05 controllers over DH‑485 or Ethernet. When replacing or upgrading from an L551, verify chassis power budget, existing program size and network configuration. It is not interchangeable with MicroLogix, ControlLogix or CompactLogix CPUs. For even larger memory requirements in the same family, users select the 1747‑L553 64K version.

Product Supply & Testing Note

We provide fully inspected and tested 1747‑L552 units. Every processor goes through power‑on cycling, Ethernet and serial port validation, memory verification and visual inspection for corrosion, burnt components or connector damage before packing. Since Rockwell ceased original manufacturing of the SLC 500 series, stock levels fluctuate rapidly. Combined orders with 1747‑BA batteries, I/O cards, power supplies and other SLC modules are welcome. If you need bulk pricing, high‑resolution product photos, firmware details or cross‑reference confirmation, send your inquiry with quantity and required lead time. We recommend replacing the backup battery during every planned maintenance cycle to prevent unexpected program loss.

Frequently Asked Questions

Q: What is the memory difference between 1747‑L551, 1747‑L552 and 1747‑L553? A: 1747‑L551 = 16K words; 1747‑L552 = 32K words; 1747‑L553 = 64K words. All three are SLC 5/05 with built‑in Ethernet.

Q: Does the 1747‑L552 support EtherNet/IP? A: Yes, it features integrated 10Base-T EtherNet/IP communication alongside the RS‑232 serial channel.

Q: What battery does 1747‑L552 use? A: It uses the 1747‑BA lithium backup battery for RAM and real‑time clock retention.

Q: Can I replace a 1747‑L551 directly with 1747‑L552? A: Yes, it is pin and chassis compatible, but confirm your power supply rating and that your RSLogix 500 project fits within the available memory.

Q: What software do I use to program this processor? A: RSLogix 500 is the official programming software for all SLC 500 processors including the 1747‑L552.

Why Choose Us for 1747‑L552

We specialize in tested legacy Allen‑Bradley SLC 500 automation spare parts for global industrial buyers. We understand that upgrading or replacing an SLC 5/05 CPU is often the most cost‑effective way to extend the service life of critical production lines. Our service includes clear product photographs, anti‑static packaging, fast quotations and reliable worldwide shipping. Our team can help you cross‑check compatible accessories, backup batteries and alternative processor options when stock is limited.

1747-L551