Replace the controller,
not the production schedule.
PLC and DCS migrations that replace end-of-life platforms without disrupting production — phased cutovers, logic restructuring, and operator training.
Obsolete controllers running on borrowed time. Spare parts on 6-month lead times. Programming software on Windows XP.
- —Surplus parts from third-party dealers
- —No one who understands the original logic
- —One failure away from weeks of downtime
Current platform, documented logic, available parts, and a team that can maintain it.
- Supported hardware with available spares
- Restructured, documented program
- Trained operators and maintenance team
Plan the path
before the crisis forces your hand.
Your PLC-5 still runs. Your SLC-500 still scans. The problem isn't that it stopped working — it's that it's approaching the point where it can't be supported. Replacement parts are on 6-month lead times from surplus dealers. The programming software runs on Windows XP. The one engineer who understood the original logic retired three years ago.
Migration isn't urgent until it is. Then it's an emergency, and emergencies don't produce good engineering. We plan the path before the crisis forces your hand — phased cutover strategies, risk assessments, logic conversion, and operator training.
Every month it keeps running is another month closer to a failure that takes the line down for weeks instead of days.
From assessment
to running system.
Legacy System Assessment
Comprehensive evaluation of your existing control system: hardware inventory, software versions, spare parts availability, firmware revisions, network architecture, and remaining manufacturer support status. The assessment also covers the logic itself — how it's structured, whether it's documented, and whether there are undocumented modifications. Deliverable: a migration assessment report with hardware lifecycle status, risk ranking, recommended migration path, and rough order of magnitude cost and timeline.
Migration Planning and Risk Management
Migration plans designed around your production schedule, not the other way around. Phased cutover strategies that allow migration area by area, machine by machine, or line by line — maintaining production throughout. Risk identification and mitigation for every phase: rollback plans, cutover windows, production impact analysis, and contingency for hardware delivery delays. We plan for realistic risks — technical, operational, and organizational.
Logic Conversion and Restructuring
Converting existing PLC/DCS programs from legacy platforms to current hardware and software. This is not a one-click conversion. Automated tools handle the mechanical translation. We handle the engineering: restructuring monolithic programs into modular architectures, replacing undocumented workarounds with proper logic, updating alarm configurations, and redesigning sequences built around old platform limitations. The new program does what the old one did — but it's organized, documented, and maintainable.
Hardware Specification and Design
New controller hardware specified, I/O modules selected, racks laid out, and panels designed. Legacy I/O points mapped to new module positions. Reusing existing field wiring where possible to minimize installation scope. Interface terminal blocks that allow legacy field wiring to land on new I/O modules without re-terminating every conductor. Network migration: PROFIBUS to PROFINET, DH+ to EtherNet/IP, serial to Ethernet.
HMI and SCADA Migration
Legacy operator interfaces migrated to current platforms. Screen conversion, tag database migration, alarm reconfiguration, and historian transition. We don't just convert old screens to new screens — migration is the opportunity to redesign operator graphics according to high-performance HMI principles, replacing cluttered legacy screens with clean, situation-aware displays that operators actually trust and use.
Cutover Execution and Training
On-site cutover managed by the engineers who designed the migration. I/O landing verification, power-up sequencing, communication checkout, and initial system testing. Hot cutover or cold cutover selected based on process tolerance. Rollback plans in place for every cutover. Operator and maintenance training delivered on the actual system, using your process context — not a generic vendor training class.
Every legacy platform,
a path forward.
We've migrated PLC-5s, SLC-500s, S7-300s, legacy DCS platforms, and proprietary controllers — in facilities that can't afford to stop production.
Allen-Bradley PLC-5 → ControlLogix
The most common migration we execute. PLC-5 processors, 1771 I/O, and Data Highway Plus networks migrated to ControlLogix, 1756 I/O, and EtherNet/IP. Wiring adapters available to reduce field wiring changes.
Allen-Bradley SLC-500 → CompactLogix
SLC-500 processors and 1746 I/O migrated to CompactLogix and 5069 Compact I/O. Program conversion from RSLogix 500 to Studio 5000 with instruction set differences handled during conversion.
Siemens S7-300/400 → S7-1500
Migration from STEP 7 Classic to TIA Portal. PROFIBUS to PROFINET network migration. ET200M remote I/O replacement with ET200SP. Logic conversion and restructuring within TIA Portal.
DCS to PLC-Based Control
Legacy DCS platforms (Honeywell TDC, Foxboro I/A, Bailey INFI 90) migrated to modern PLC-based process control or current-generation DCS. Control strategies, graphics, historian, and batch management all transition.
Proprietary and OEM Controllers
Custom controllers and proprietary systems migrated to standard PLC platforms. Reverse-engineering existing functionality from observation and documentation when source code doesn't exist.
Facilities Planning Expansion
New production lines that need to integrate with existing legacy systems. Migration of the legacy system becomes part of the expansion scope, consolidating the facility on a current, supportable platform.
From legacy system
to current platform.
Assess.
Hardware inventory, software audit, program documentation, risk evaluation, and migration path recommendation. This phase defines the project scope and provides the basis for planning and budgeting.
Plan.
Migration strategy, phasing, cutover schedule, risk mitigation, and resource requirements. The plan is reviewed with your operations, maintenance, and management teams before execution begins.
Convert and build.
Program conversion, restructuring, new hardware specification, panel modifications, and HMI/SCADA migration. Factory testing of converted logic against documented system behavior.
Cut over.
On-site execution of the migration — I/O transition, controller swap, communication migration, and system startup. Managed cutover with rollback capability. Engineers on-site through the transition and initial production runs.
Stabilize and train.
Post-cutover support, operator and maintenance training, documentation delivery, and performance verification. We stay until the system is running reliably and your team is confident operating and maintaining it.
Platforms we migrate.
From legacy platforms to current, supported hardware — with the logic restructuring and documentation that makes the new system better than the old one.
Engineering discipline,
not just code translation.
We convert and restructure — not just translate.
Automated conversion tools translate PLC-5 code to ControlLogix syntax. They don't fix the spaghetti logic, remove the dead code, document the undocumented workarounds, or restructure the program into a maintainable architecture. We do both — the mechanical conversion and the engineering restructuring.
We plan for the cutover you're afraid of.
The cutover is where migration projects succeed or fail. We plan every cutover with defined steps, time estimates, go/no-go criteria, and rollback procedures. We've executed cutovers in continuous process plants, food plants that have to run Monday morning, and water treatment facilities that can't stop treating water.
We've done the hard migrations.
Undocumented PLC-5s with 20 years of modifications. Legacy DCS platforms where the vendor doesn't exist anymore. Proprietary OEM controllers with no source code. We've reverse-engineered, converted, and commissioned systems that other integrators walked away from.
Migration as an upgrade, not just a swap.
A migration is the opportunity to fix the problems the old system had — poor alarm management, undocumented logic, inconsistent naming, and missing features. The new system should be better than the old one, not just the same logic on newer hardware.
Straight answers.
It depends on the scope. A single machine with one PLC-5 and 100 I/O points might be a 4–6 week project. A plant-wide migration of multiple PLC-5s, a legacy DCS, and the SCADA system could span 12–24 months with phased cutovers. We provide a realistic timeline based on the assessment — not an optimistic estimate that slips on every phase.
Yes, and that's how most migrations should be done. Phased migration reduces risk, allows lessons learned to inform subsequent phases, and avoids the production impact of a plant-wide shutdown. The key requirement is designing the new system architecture to support coexistence with legacy systems during the transition period.
This is common, especially for systems that have been modified over many years. We reverse-engineer the existing program through code review, operator interviews, and on-site observation. It takes longer than working from documentation, but it's a solvable problem and one we encounter regularly.
If your team is trained on Allen-Bradley and your plant is standardized on it, migrating a PLC-5 to ControlLogix keeps the ecosystem consistent. Switching platforms mid-migration adds risk and training burden. That said, there are valid reasons to switch — and we'll give you a frank assessment of the tradeoffs.
We recommend maintaining legacy spares until the full migration is complete and the legacy system is decommissioned. During a phased migration, the old and new systems coexist — and the old system still needs support until it's fully replaced.
Yes. We provide migration assessments that include hardware lifecycle risk, estimated downtime exposure, spare parts cost trajectory, and a rough-order-of-magnitude investment for the migration. This gives your management team the data they need to approve the project — not just a recommendation that 'it should be done.'
Running on borrowed time?
If your control system is approaching end of life — or already past it — tell us what you're running and we'll help you plan the path forward.