The Allen-Bradley Spare Parts Challenge
Rockwell Automation's Allen-Bradley product line is one of the most widely deployed PLC platforms in North America and globally. But with a product portfolio spanning decades, many legacy components — from the PLC-5 series to early ControlLogix modules — are now discontinued or on limited availability.
For maintenance engineers and procurement teams, sourcing these parts quickly and reliably is a constant challenge.
Most Commonly Sourced Allen-Bradley Components
Based on buyer requests, the following are the most frequently sourced legacy Allen-Bradley parts:
- 1756 ControlLogix CPUs — Older firmware revisions and early L-series processors
- 1769 CompactLogix I/O modules — Digital and analog input/output modules
- 1747 SLC 500 series — Fully discontinued but still widely installed
- 1785 PLC-5 processors — End-of-life since 2022, high demand for replacements
- 20-series PowerFlex drives — Older drive variants with limited distributor stock
New vs. Surplus vs. Refurbished: What's Right for You?
When sourcing discontinued Allen-Bradley parts, buyers typically have three options:
- New old stock (NOS) — Unused units from surplus inventory. Ideal when available, but increasingly rare for older series.
- Factory refurbished — Units that have been fully tested and restored to factory specifications. A reliable option with warranty coverage.
- Used / tested — Functional units pulled from decommissioned equipment. Lower cost, suitable for non-critical applications with proper testing documentation.
How to Verify Authenticity
Counterfeit Allen-Bradley components are a known problem in the secondary market. When sourcing from any supplier, request:
- High-resolution photos of the physical unit and label
- Serial number verification where possible
- Functional test report
- Clear warranty and return policy
Request Allen-Bradley Parts from NORTHLINK
NORTHLINK sources verified Allen-Bradley components through a global network of qualified suppliers. Submit your part numbers through our Request a Quote page and receive availability and pricing within 24 hours.