PLC Upgrade & Migration — Siemens, Allen-Bradley

Many plants in Reynosa and Tamaulipas operate with PLCs that have been in service for 15 or 20 years: Siemens S5, Siemens S7-200, Allen-Bradley SLC-500 or PLC-5. While they work, nobody touches them. The problem comes when they fail: the manufacturer no longer makes spare parts, distributors have second-hand units with unknown history and the technician who knew that platform retired years ago. In that scenario, an obsolete PLC that fails can mean weeks of downtime while an emergency solution is found.

At Reynotech we execute PLC migrations for industrial plants in Reynosa and Tamaulipas. The process includes recovery and documentation of the original control logic — even when no documentation exists — program conversion to the target platform with functional preservation of all interlocks and safety sequences, communication hardware update to modern industrial networks (Profinet, EtherNet/IP), and complete testing in a controlled environment before plant startup to guarantee the equipment operates exactly like the original system.

We plan the migration in scheduled maintenance windows to minimize impact on production: the new system is prepared, tested and validated offline while the original equipment continues operating. The cutover happens during the lowest production impact period. Upon completion, we deliver complete updated technical documentation for the migrated equipment — control logic, as-built electrical diagrams, configuration guide — so the maintenance team can operate the system autonomously without depending on us for every intervention.