PLC Programming & Software Development

Contract PLC programming support specialising in Siemens TIA Portal (v15-v20) for industrial automation systems across marine, energy, steel, and manufacturing sectors.

Structured software development aligned with IEC 61131-3 and Siemens programming guidelines, delivered through contract engagements for system integrators, OEMs, and project delivery organisations.

Core PLC Programming Capabilities
TIA Portal Development (S7-1200/1500)
Structured Programming (IEC 61131-3)
System Integration (Drives, I/O, Networks)
Simulation & Testing (PLCSIM Advanced)
Commissioning Support

PLC Software Development

PLC software development is delivered using structured programming methods aligned with IEC 61131-3 standards and Siemens best practices.

Development approach includes:

Software Architecture

  • Modular program structure using organization blocks (OBs), function blocks (FBs), and functions (FCs)
  • User-Defined Types (UDTs) for consistent data structures across system components
  • Reusable library development for standardized equipment control (valves, pumps, motors)
  • Clear tag structures supporting SCADA integration and long-term maintainability

Control Logic Development

  • Ladder logic (LAD) and Structured Control Language (SCL) implementation
  • State machine programming for sequential control and mode management
  • Interlock logic derived from FDS and P&ID documents
  • PID control loops for process variables (temperature, pressure, level, flow)

Safety Integration Support

  • Fail-safe CPU (F-CPU) programming support under senior engineer guidance
  • Safety interlock implementation with diagnostic transparency
  • Integration with safety PLCs and safety I/O modules

Development is supported by simulation-first methodology using PLCSIM Advanced and virtualised test environments, allowing full program validation prior to commissioning.

Platform Expertise

Primary development platform is Siemens TIA Portal (v15-v20) with supporting experience in FactoryTalk for HMI integration.

Siemens TIA Portal (v15-v20)

S7-1200 Series
CPU 1211C, 1212C, 1214C, 1215C, 1217C
S7-1500 Series
CPU 1511, 1513, 1515, 1516, 1518
ET200SP
Distributed I/O modules
F-CPU Support
Fail-safe programming with specialist guidance

Development Tools

  • Hardware configuration and I/O mapping
  • Tag structure development and PLC data type architecture
  • Organization block (OB) programming and cyclic interrupts
  • Diagnostic programming using system functions
  • TIA Portal library management and version control discipline
  • Multi-engineer collaboration via TIA Portal Server (Acteon project exposure)

Supporting Platforms

FactoryTalk ME
HMI development and tag structure analysis from Studio 5000
Simulation Tools
PLCSIM Advanced, Modscan, Proneta

Programming Standards & Methods

PLC programming follows industry standards and manufacturer guidelines to ensure maintainable, testable, and commissioning-ready code.

IEC 61131-3 (PLC Programming Languages)

  • Ladder Diagram (LAD) for discrete logic and interlocks
  • Structured Control Language (SCL) for complex calculations and data processing
  • Function Block Diagram (FBD) where appropriate for process control
  • Sequential Function Chart (SFC) for batch processes and sequence architecture

Siemens Programming Guidelines

Programming follows Siemens guidance for SIMATIC S7-1200 and S7-1500 structure and maintainability:

  • Structured organization of cyclic, alarm, and diagnostic OBs
  • Consistent naming conventions for tags, blocks, and data structures
  • Commented logic sections for operational and maintenance visibility
  • Block sizing discipline to keep logic maintainable and testable
  • Symbolic addressing used across implementation

Simulation & Testing

  • Full program simulation with PLCSIM Advanced before deployment
  • Analogue input simulation structures for commissioning preparation
  • Modbus TCP simulation with Modscan for meter integration testing
  • I/O module selective inhibit functions for controlled FAT execution
Recent Application

Protium Hydrogen Production Plant (2025)

Assisted lead engineer in building PLC architecture from FDS and P&ID documents following Siemens programming guidelines. Implemented Modbus TCP client for PAC3220 meters with diagnostics, developed PID-controlled tank-level logic with simulation-ready structures, and created UDT-driven interlocks with OB-based error handlers for improved fault visibility. Role: Assistant Controls Engineer under senior guidance.

Integration & Communication

PLC programming includes integration with industrial networks, field devices, and supervisory systems.

Industrial Networks

Profinet
Device configuration, topology checks, and diagnostics with Proneta
Profibus DP
Slave integration and GSD-based configuration support
Modbus TCP/IP
Client and server mapping, register handling, PAC3220 integrations

Drive System Integration Support

PLC-to-drive communication and control logic development with specialist support for advanced commissioning:

  • PLC-to-drive communication setup (Profinet and hardwired I/O)
  • Basic drive control logic (start/stop, speed reference, status handling)
  • Drive fault monitoring and alarm integration into PLC logic
  • Commissioning support alongside drive specialists

Advanced drive commissioning such as parameter tuning, motion profiling, and torque control is delivered in collaboration with dedicated drive specialists or client drive engineers.

SCADA & Data Exchange

OPC UA
Server setup, tag publishing, and MATLAB or SCADA integration paths
Tag Structures
Export structures for WinCC, AVEVA, and FactoryTalk clients
IBA Integration
S7 Explorer data point structure for high-speed acquisition
Recent Application

CEMEX Innovate UK Phase II (2025)

Created Modbus TCP data capture structures for BESS values mapped to OPC UA server tags. Configured OPC UA publication in TIA Portal to bridge into MATLAB Simulink models, integrated five PAC3220 power meters with health diagnostics, and used Proneta for network verification during commissioning.

Project Examples

Recent PLC programming delivery across marine, energy, and industrial sectors.

CEMEX Innovate UK
Shore-to-ship power demonstrator architecture: PLC to Modbus to OPC UA to MATLAB data pipeline, five PAC3220 integrations, structured alarm framework, and SCALANCE router support.
Platform: MTP1500, TIA Portal v20, S120 drives
Port Talbot - IBA Data Logger
IBA PDA/Capture server: 3-NIC architecture, eight PoE IP cameras, Cisco CBS350 VLANs via CLI, and S7 Explorer PLC link for synchronised high-speed process data and video capture.
Platform: ibaPDA/Capture, WinCC Pro, TIA Portal v15
Protium Hydrogen Plant
PLC architecture support with Modbus TCP client structures for PAC3220 meters, PID tank-level logic, and simulation-ready commissioning models. Assistant role under senior engineer.
Platform: TIA Portal v20, S7-1500
Acteon - Seabed Drilling System
Seabed drilling HMI lead: 80+ ISA-101 screens, 100+ reusable UDT faceplates, and 1,000-line VB safety module for F-CPU SIL compliance across a four-month multi-engineer project.
Platform: WinCC Unified, TIA Portal v18, ESXi Server
Global Marine - Amsterdam
Cable-laying vessel commissioning support including I/O verification, Nidec drive integration checks, communication troubleshooting, and sequence testing.
Platform: TIA Portal v18, S7-1500
PD&MS Power Buoy
Static 50-to-60Hz marine power conversion controls with Modbus frameworks for Schneider meters, alarm structuring, sequence control, and drive integration support.
Platform: S7-1200/1500, SINAMICS S120

Projects delivered across marine, energy, steel, and manufacturing sectors for clients including CEMEX, Global Marine, Protium, PD&MS Group, and Tata Steel.

Deliverables

PLC Programming Scope

  • Complete PLC program development from FDS and electrical schematics
  • Hardware configuration in TIA Portal (CPU, I/O modules, and networks)
  • Structured program architecture with modular blocks and reusable libraries
  • Alarm generation and diagnostic programming
  • Communication configuration (Profinet, Modbus, OPC UA)
  • Simulation and offline testing using PLCSIM Advanced

Documentation

  • Tag lists with descriptions and data types
  • Block descriptions and functional explanations
  • Network topology and device addressing records
  • Modbus register maps and communication notes
  • Alarm lists with severity and response requirements

Commissioning Support

  • Program download and online diagnostics
  • I/O verification and signal testing
  • Network diagnostics with Proneta and manufacturer tooling
  • Fault finding and logic troubleshooting
  • Site modifications and post-commissioning optimisation

Handover

  • Backup files with revision control records
  • Structured source code handover with comments
  • Configuration exports for drives, networks, and field devices
  • Knowledge transfer support for client engineering teams

For scope review, platform fit checks, or delivery support planning, use the Contact page.

Contact Check Availability