Freelance PLC Programmer – Frankfurt - Hybrid
Project Overview:
We are seeking a skilled Freelance PLC Programmer to support industrial automation projects involving Siemens PLCs (TIA Portal) and WAGO I/O systems. The ideal candidate will have a strong background in configuring and programming complex control systems using Structured Text (ST) and experience with industrial network protocols like Profinet and Profibus. The freelancer will collaborate with cross-functional engineering teams to design, implement, test, and troubleshoot PLC-controlled systems in line with project requirements.
Key Responsibilities:
Design and develop PLC control programs using Siemens TIA Portal.
Write clean, modular code in Structured Text (IEC 61131-3 ST).
Integrate and configure WAGO hardware, especially 750/753 series I/O modules.
Set up and troubleshoot communication via Profinet and Profibus protocols.
Develop and validate HMI/SCADA interfaces (optional depending on scope).
Conduct on-site or remote commissioning, FAT (Factory Acceptance Testing), and SAT (Site Acceptance Testing).
Collaborate with electrical engineers to interpret wiring diagrams, IO lists, and process descriptions.
Create technical documentation, including logic descriptions, user manuals, and system configurations.
Provide support for new product or technology introductions and system upgrades.
Debug system faults and provide remote troubleshooting support during operations.
Required Qualifications:
Proven professional experience (3+ years) in Siemens PLC programming, specifically TIA Portal (S7-1200/S7-1500).
Strong command of Structured Text (ST) programming.
Hands-on experience with industrial network protocols : Profinet, Profibus, and optionally Modbus.
Experience with WAGO PLCs and remote I/O systems, especially with Codesys -based environments and fieldbus configuration.
Familiarity with safety PLCs and failsafe programming is a plus.
Ability to read electrical schematics and interface documentation.
Knowledge of HMI/SCADA platforms (e.g., WinCC, Ignition, FactoryTalk).
Fluent in English (written and spoken); German is a plus for European projects.
Preferred Qualifications:
Experience in Codesys -based environments.
Background in industrial sectors such as water treatment, packaging, automotive, or energy.
Understanding of OPC UA, MQTT, or other IIoT-related protocols.
Deliverables:
Fully functional and tested PLC code and configurations.
Configuration of WAGO I/O modules and network communication setup.
Technical documentation and maintenance guidelines.
Remote or on-site commissioning and support documentation.