🔧 What Is the Allen-Bradley SLC 500 Platform?

The Allen-Bradley SLC 500 series by Rockwell Automation is one of the most trusted programmable logic controller (PLC) platforms used in industrial environments for over 30 years. Although considered a legacy system, it continues to operate reliably in facilities ranging from automotive plants to wastewater treatment and packaging lines.

🧱 Core Components of the SLC 500 System

✅ Allen-Bradley SLC 500 CPU Controllers

These programmable controllers (like 1747-L542, 1747-L552, 1747-L553) process logic, math, and PID functions and communicate via serial or Ethernet ports. Available in fixed and modular configurations, they are the "brain" of the SLC 500 system.

✅ Allen-Bradley SLC 500 Rack Chassis

Chassis are available in 4-slot, 7-slot, and 10-slot versions. They hold the CPU, power supply, and I/O modules, allowing easy system expansion and maintenance.

✅ Full Family – Allen-Bradley SLC 500 Controllers

This includes everything: CPUs, racks, power supplies (1746-P1, P2), discrete and analog input/output modules, and communication interfaces (DH+, Ethernet, RS-232).

⚙️ Why Do Industries Still Use SLC 500?

• ✔️ Proven Reliability: Many plants still operate 24/7 on SLC 500 systems installed in the 90s.

• 🔄 Easy Maintenance: Hot-swappable modules, simple diagnostics, and strong software support.

• 💡 Software Compatibility: Works with RSLogix 500, still maintained by Rockwell for legacy applications.

• 📦 Replacement Simplicity: Easy to swap failing modules with no program changes.

🔎 Best-Selling Part Numbers (In Stock)

• 1747-L552 – 32K CPU with DH+/RS232

• 1747-L553 – Highest memory and fastest SLC CPU

• 1746-A10 – 10-slot chassis for large systems

• 1746-P2 – Standard power supply

• 1746-IB16 / 1746-OB16 – Digital input/output modules

• 1746-NI4 / 1746-NO4I – Analog modules for sensors and actuators

All of these are available in our SLC 500 Controllers collection

(Expertise, Experience, Authoritativeness, Trustworthiness)

• Expertise: We specialize in sourcing, testing, and supplying legacy automation hardware—SLC 500 is one of our core strengths.

• Experience: 10+ years supporting clients in automotive, food & beverage, pharma, and energy industries with legacy Allen-Bradley systems.

• Authoritativeness: All parts are tested and verified before shipping. We maintain consistent stock and offer documentation support.

• Trustworthiness: Transparent listings, fast response times, and worldwide shipping from the USA make us a trusted source for industrial PLC hardware.

❓ Frequently Asked Questions (FAQ)

Q1: Is the SLC 500 obsolete?
Technically yes, Rockwell has phased it out—but it's still fully supported and actively used in thousands of systems worldwide.

Q2: Can I upgrade from SLC 500 to CompactLogix or ControlLogix?
Yes, Rockwell provides conversion kits, but it can be costly. Replacing individual modules often extends the system life at a fraction of the price.

Q3: Are SLC 500 power supplies cross-compatible across racks?
Yes, models like the 1746-P1 and 1746-P2 are compatible with multiple SLC rack sizes.

Q4: Do you test the equipment before shipping?
Yes, every module is tested, cleaned, and securely packaged before shipping.