Allen-Bradley 1747-L551 Module

The Allen‑Bradley 1747‑L551 is a SLC 5/05 CPU processor module for the SLC 500 modular system, designed for industrial control applications needing Ethernet connectivity. It integrates 16KB battery‑backed RAM (12K program/4K data) with Flash EEPROM backup, built‑in Ethernet (10/100 Base‑T) and RS‑232 ports, and scalable I/O (up to 4096 digital I/O points, 480 analog I/O points) to deliver reliable, real‑time control in manufacturing, material handling, and process automation. Discontinued by the manufacturer (as of December 31, 2021), it remains a trusted solution for legacy system upgrades and replacements, with full backward compatibility and global compliance

1. 16KB battery‑backed RAM user memory with Flash EEPROM backup for secure data retention
2. Built‑in Ethernet (10/100 Base‑T) and RS‑232 ports for flexible integration with HMIs, SCADA, and legacy devices
3. Supports up to 4096 digital I/O points and 480 analog I/O points for scalable system design
4. Fast program scan time (0.9 ms/Kword) and bit execution (0.37 μs) for responsive control logic
5. Real‑time clock/calendar, online programming, and mode‑select keyswitch (Program/Run/Remote) for operational flexibility

Application Scenarios:

• Automated Manufacturing Lines: Controls assembly machines, conveyors, and quality inspection systems with fast scan times and reliable DH+ communication.
• Material Handling: Manages warehouse automation (palletizers, sorters, and inventory sensors) via seamless integration with legacy devices through RS‑232.
• Process Control: Supports medium‑scale chemical, food & beverage, and water treatment processes with PID and advanced math functions.
• Building Automation: Integrates HVAC, lighting, and security systems for centralized facility control.
• Legacy System Upgrades: Seamlessly replaces older SLC 500 processors while preserving existing I/O and programming.