Louis Dreyfus PLC Upgrade Project Brazil | SENTRADO
A detailed case study of SENTRADO's industrial automation solution delivering measurable results for food processing operations in Brazil.
Project Background & Objectives
Louis Dreyfus Company (LDC), one of the world's largest agricultural commodity traders, engaged SENTRADO to execute a high-stakes PLC upgrade at their soybean processing facility in Brazil. The project involved migrating aging PLC systems on active production lines to a modern, high-availability Siemens platform without any unplanned production interruption — a requirement that demanded meticulous planning, parallel operation capability, and deep expertise in live system migration.
The existing installation comprised multiple generations of PLC hardware from different vendors, accumulated over years of incremental line expansions. This heterogeneous environment created maintenance challenges, spare parts obsolescence, and limited the plant's ability to implement advanced process optimization. LDC required a migration path that would standardize on a single platform while preserving the production uptime essential for their global supply commitments.
SENTRADO was selected based on our demonstrated expertise in zero-downtime PLC migration for continuous process plants, our Siemens Certified System Integrator (Professional Grade) status, and our ability to deploy a bilingual engineering team (English and Portuguese) for the duration of the project.
Problems We Had to Solve
1. Obsolescence Risk
The installed PLC base included two discontinued controller families with diminishing spare parts availability. A single CPU failure could result in days of downtime while sourcing replacement components on the secondary market.
2. Continuous Operation Mandate
As a critical node in LDC's global oilseed supply chain, the plant processes thousands of tons daily. Any unplanned stoppage would cascade through logistics chains, incur contractual penalties, and affect downstream refining operations across multiple continents.
3. Multi-Vendor Environment
The existing control system mixed Siemens S5, Allen-Bradley PLC-5, and various third-party controllers with different programming environments, communication protocols, and documentation standards — making unified support extremely difficult.
4. Signal Mapping Fidelity
Migrating hundreds of I/O points required 1:1 signal mapping with zero errors. A single miswired or misconfigured signal could cause a process upset, equipment damage, or safety hazard during cutover.
5. Documentation Gaps
Years of ad-hoc modifications meant existing electrical drawings and PLC program documentation did not reflect the actual installed configuration. The migration team had to reverse-engineer the current state before designing the replacement system.
Our Approach & System Architecture
SENTRADO engineered a phased migration to the Siemens S7-400H high-availability platform, deploying redundant CPUs with automatic switchover in under 100 milliseconds. The migration was executed line by line, with each production area converted independently during scheduled maintenance windows. New control cabinets were pre-built and pre-tested at SENTRADO's facility, then installed alongside the existing cabinets with temporary cross-wiring harnesses.
To achieve zero-downtime cutover, SENTRADO implemented a parallel-run architecture. Signal splitters were installed on critical I/O points, allowing both the old and new controllers to simultaneously receive field signals. During each cutover window, the new PLC was started in shadow mode — processing all logic but with outputs disabled — while the old system maintained control. Once the new system's behavior was validated against the old system for a full production cycle, outputs were transferred with a single physical switch, and the old system was placed on standby.
All I/O was migrated to ET 200SP HA distributed stations with hot-swap capability, meaning individual modules can be replaced without powering down the station or stopping the process. The application software was re-engineered from the ground up using modern structured programming practices, with comprehensive function block libraries for common control strategies. WinCC SCADA was upgraded with new process graphics, alarm management, and a production reporting module. The entire project was completed without a single minute of unplanned downtime.
System Architecture Highlights
- Siemens S7-400H redundant controllers with <100ms switchover
- ET 200SP HA distributed I/O with hot-swap modules
- Parallel-run migration with signal splitters for zero-downtime cutover
- Phased line-by-line migration during scheduled maintenance windows
- 1:1 signal mapping with full loop verification before each cutover
- Re-engineered application software using structured programming
- WinCC SCADA upgrade with advanced alarm management
- Complete as-built documentation package (Portuguese/English)
System Parameters & Configuration
| Control System | Siemens SIMATIC S7-400H |
| Controllers | 3 × CPU 412-3H (redundant pairs) |
| Total I/O Points | 1,800+ (AI: 240, AO: 80, DI: 1,050, DO: 430) |
| Communication Protocol | PROFINET / PROFIBUS DP / Modbus TCP |
| HMI / SCADA | WinCC RT Professional — 3 OS + 1 EWS |
| Control Cabinets | 6 × IP54 with redundant power |
| Distributed I/O Stations | 10 × ET 200SP HA |
| Redundancy Switchover | <100 milliseconds |
| Power Range | 480V 3-phase, 60Hz |
| Migration Approach | Phased parallel-run with zero downtime |
| Hot-Swap I/O | All modules replaceable under power |
| Post-Upgrade Downtime | Zero unplanned stoppages |
Key Components & Hardware
Siemens CPU 412-3H
6ES7412-3HJ14-0AB0
Redundant high-availability controller
ET 200SP HA I/O
6DL5110-0AL10-0AX0
Hot-swap distributed I/O station
WinCC RT Professional
6AV2105-0DA06-0AA0
SCADA with redundancy option
SCALANCE X204RNA
6GK5204-0BA00-2KB2
Redundant PROFINET ring switch
SITOP PSU8600
6EP3437-8SB00-0AY0
Redundant 24V/40A power supply
SIRIUS 3RV2 Breaker
3RV2031-4UA10
Motor protection circuit breaker
Rittal VX25 Cabinet
VX 8806.000
Bayable enclosure system
Signal Splitter Relay
3TX7002-1AB00
Parallel-run signal isolation
Project Phases
Site Survey & Reverse Engineering
4 weeksDocument existing configuration and I/O
Design & Engineering
6 weeksNew system architecture, panel design, software spec
Panel Manufacturing
4 weeksPre-build cabinets with all components
Software Development
8 weeksPLC programming, HMI, simulation testing
Phased Migration (Line 1)
3 weeksInstall parallel system, validate, cutover
Phased Migration (Line 2)
3 weeksSame methodology for second line
Phased Migration (Line 3)
3 weeksFinal line cutover and old system removal
SAT & Handover
2 weeksFinal acceptance, documentation, training
Measurable Outcomes
Performance data verified after system commissioning and sustained operation.
Zero production stoppages during migration
Recipe switching time reduced
Single Siemens platform across all lines
SENTRADO remote diagnostic access
Before vs After: Quantified Comparison
| Metric | Before | After | Change |
|---|---|---|---|
| Unplanned downtime | Recurring stoppages | 0 during migration | −100% |
| Recipe changeover | 2–3 hours | 30% faster | −30% |
| PLC platform | Mixed S7-300/400 + third-party | 100% Siemens standardized | Unified |
| Remote support | On-site only, delayed | 24/7 remote diagnostic access | Always-on |
| Spare parts availability | Obsolete, long lead times | Current-gen S7-1500, readily available | Secured |
Data based on project commissioning reports and sustained operational measurements. Client name available under NDA.
Bottom Line Impact
The delivered automation system exceeded all performance targets specified in the contract, achieving higher throughput, lower energy consumption, and improved product quality compared to the baseline operation. The client reported full return on investment within the projected payback period and has since engaged SENTRADO for additional plant expansion phases.
Have a Similar Project?
Whether you need a complete DCS migration, custom PLC control cabinets, or a turnkey automation solution, our engineers are ready to help. Get a free consultation and quote today.