The challenge: integrate a process machine with three servo axes and thermal subsystems
The client, a Valencian manufacturer with a plant in L'Horta, had purchased a specialised process machine from an international OEM. The machine combined three coordinated servo axes (a pressing axis, a transfer axis and a fixed axis) with several auxiliary subsystems: water pumps, water and air heating, blowing, brushing and a positioning jack system. The mechanical side worked, but the electrical and control side had two critical issues: it did not comply with the EU CE directive and the documentation was non-existent, leaving the client unable to maintain or evolve the equipment.
The company contacted us looking for an automation engineering partner in Valencia able to cover the full lifecycle: redesign the electrical part with EU-compliant components, build the cabinet in-house, reprogram the PLC with a maintainable architecture, and commission the machine on-site with CE declaration and complete handover documentation.
Solution architecture
We designed the cabinet from scratch in Eplan Electric P8, with our own macros and corporate library, ensuring traceability for every terminal, cable and commercial reference. The architecture was organised in four physical zones inside the panel, aligned with the functional identifiers labelled on the yellow rails: main power, control and PLC, power and servo drives, and field terminal block.
Siemens S7-1200 PLC with modular expansion
For the main controller we selected a Siemens S7-1200 with seven I/O expansion modules (digital and analog). Choosing the S7-1200 over an S7-1500 was justified by the I/O count required (around 80 inputs and 60 outputs), the project budget and immediate availability. For processes with tighter cycle time or higher I/O density we would go for the upper range — the decision is taken process by process, as we discuss in our Siemens S7-1200 vs S7-1500 guide.
Programming was done in TIA Portal with a modular structure per subsystem: general management block, safety block, one block per thermal subsystem, three-axis servo coordination block and communications block. Each block exposes a clean interface of inputs, outputs and parameters, allowing the client's maintenance team to intervene on a single subsystem without risk of impacting the rest.
Three coordinated SINAMICS servo drives
The three mechanical axes — pressing axis, transfer axis and fixed axis — are driven by three Siemens SINAMICS servo drives communicating with the PLC over Profinet. Inter-axis synchronisation runs on motion profiles managed from the S7-1200 using its built-in Motion Control technology, avoiding the need for a dedicated technology CPU.
The pressing axis controls force and position during the main operation. The transfer axis moves parts between stations. The fixed axis maintains the product's positioning reference throughout the cycle. The three axes are integrated into the cabinet's functional safety architecture, with Safe Torque Off (STO) handled from the SIRIUS safety relays.
SIRIUS safety architecture
Functional safety is implemented with Siemens SIRIUS safety relays and motor protection from the same family, sized according to the machine's risk assessment and validated against ISO 13849-1 categories. Coverage includes emergency stop, electromechanically interlocked guards and servo drive monitoring. All safety functions route through a single safe bus to the PLC, simplifying alarm handling and diagnostics.
Auxiliary subsystems: pumps, heating and blowing
The SIRIUS motor protection on the upper section of the cabinet manages the three-phase motors of the auxiliary subsystems: water pump, air blower, brushing system and circulation pumps. Heating splits into two independent circuits — water heating and air heating — controlled from the PLC via analog outputs to power regulators, with PT100 feedback in each zone.
The 24 V DC control supply is provided by a MeanWell NDR-240-24 DIN-rail PSU, sized with a 30% margin over calculated peak consumption. Control circuit protection is handled by Siemens miniature breakers and fourteen general-purpose auxiliary relays (KA1–KA14) that isolate the PLC from field loads.
Main breaker and power switchgear
The main breaker and the magneto-thermal differential protection were resolved with Schneider Electric switchgear, keeping consistency with the client's installed base and ensuring local spare-part availability. Downstream distribution to the servo drives and motor protection runs through busbars and terminal blocks with selectivity calculated in Eplan.
In-house cabinet build
The cabinet was fully assembled in our workshop, with finished wiring, every terminal and cable labelled per the drawing, functional identification on the rails and electrical pre-delivery testing. Before shipment we ran a Factory Acceptance Test (FAT) without the machine, simulating inputs with a test bench and validating every output with equivalent loads. The FAT protocol was signed off with the client over video call, with evidence capture and a record for every test executed.
Building in-house lets us guarantee the schedule and the quality of the assembly, and deliver the cabinet ready to wire on-site. It is the standard practice across our turnkey control cabinet manufacturing projects.
On-site commissioning and validation
On-site installation took four days: cabinet hook-up, machine actuator and sensor wiring, initial servo drive parameterisation and subsystem-by-subsystem startup. The validation process included:
- Per-subsystem functional validation: each auxiliary subsystem (heating, pumps, blowing) is started independently and closed-loop control is verified.
- Servo axis tuning: SINAMICS gain tuning, motion profile validation and inter-axis synchronisation check at slow cycle.
- Safety validation: testing each safety function (emergency stop, guard opening, STO on each servo) with response time verification.
- Supervised production: two real production shifts with the responsible engineer on-site, tuning recipes and parameters based on observed behaviour.
- Signed SAT: Site Acceptance Test protocol, signed by the client's maintenance lead.
Results and deliverables
- Machine running with CE marking and signed declaration of conformity, documented risk assessment and ISO 13849-1 safety categories validated.
- Full documentation handover: Eplan schematics in editable format and PDF, bill of materials with commercial references, operator and maintenance manuals and TIA Portal project backup.
- Reduced recipe changeover times compared to the previous behaviour of the machine, thanks to the new HMI recipe manager and structured PLC diagnostics.
- Internally maintainable cabinet: the client's team can swap any component using its documented commercial reference and diagnose faults from the HMI without external support.
- Post-delivery support: annual contract with secure remote access and 24 h SLA, within our standard control system maintenance offering.
What made the difference
The difference is not in any single component — Siemens S7-1200, SINAMICS and SIRIUS are well-known standard hardware. The difference is in approaching the project as full integration: complete electrical redesign, in-house build, programming with maintainable architecture and on-site commissioning, all from the same team. The client got not just a machine that runs, but a maintainable machine, with documentation that lets them operate and evolve the system without integrator dependency.
This is the recurring pattern in many of the projects we tackle across the Valencian Community: machines purchased from international OEMs that need normative adaptation, EU-grade electrification and documented programming to fit into a Spanish industrial plant without breaking technical traceability.
If you have an imported machine that needs electrical adaptation, CE marking or PLC reprogramming, share the details with us. We will assess technical feasibility and project scope at no obligation.