ABN (Associated British Nutrition)

ABN, a leading UK manufacturer of monogastric compound feed for the pig and poultry industries, operates 10 mills across the country under the Associated British Foods group. At its Bury St Edmunds plant, blending, grinding, pressing and bagging processes demand precise, uninterrupted control to meet stringent quality and ingredient standards. A review of the site's automation infrastructure revealed that the Allen-Bradley PLC-5 controllers installed since 1989 were approaching obsolescence — spare parts were becoming scarce, and hardware failure risk was rising. Replacing the aging DH+ network and legacy control system without disrupting 24/7 production was the central constraint.

Rockwell Automation Recognised System Integrator Datastor Systems Ltd. designed a phased migration to a modern Integrated Architecture platform, executed across four planned weekend shutdowns to minimise production impact. The core of the strategy was reusing existing I/O hardware: the Allen-Bradley 1771-to-1756 IO Swing-arm Conversion System allowed legacy PLC-5 I/O modules to connect directly to new ControlLogix PACs without rewiring terminal connections. Existing SLC-5/04 controllers in the grinding and blending areas were retained as remote I/O via 1747-AENTR EtherNet/IP adapter modules, bridging them into the new ControlLogix environment. A SCADA layer running on standard PCs was layered above the PACs. EtherNet/IP replaced the legacy DH+ network, enabling both in-house operator visibility and external remote access for Datastor's support team.

The migration went live in January/February 2015 with no reported issues post-cutover. Key outcomes included:

• Faster, more robust network: EtherNet/IP delivered materially better throughput and reliability than the legacy DH+ infrastructure
• Reduced migration risk: Reusing existing I/O swing-arms eliminated rewiring errors and cut changeover time significantly across four weekend phases
• Remote access enabled: ABN gained its own remote monitoring capability; Datastor now provides remote support across all ABN sites, reducing call-out costs and response times
• Improved OEE and asset utilisation: Greater process visibility through graphical diagnostics from network to hardware level
• Lower whole-life cost: Open EtherNet/IP protocols simplify future upgrades compared to the proprietary DH+ predecessor

• Reuse existing I/O where possible: Swing-arm conversion hardware can eliminate rewiring entirely, cutting both cost and the risk of wiring errors during legacy PLC migrations.
• Phase migrations across planned shutdowns: Four weekend outages delivered a complete platform change without disrupting continuous production — a model replicable at other 24/7 food manufacturing sites.
• Open protocols pay dividends long-term: Migrating to EtherNet/IP reduced future upgrade complexity and unlocked remote access capabilities unavailable on proprietary networks.
• Audit spares availability early: A traffic-light spares analysis was the trigger for this project — a practical first step for any site still running 20+ year-old automation hardware.