Senior Controls Software Engineer - PLC & CODESYS Expert

IMS People; Seattle (WA); On-site; USD 120,000 - 160,000; Full time

Job summary

IMS People is seeking a Controls Software Engineer to support a next-generation material handling controls platform in a large-scale robotics and automation environment. You will develop reusable controls software using ST and IEC 61131-3, with CODESYS V3 or TwinCAT, on Linux-based industrial PCs, and collaborate across controls, software, electrical, and automation teams.

The role emphasizes greenfield development, state-machine architecture, debugging, and deployment of controls applications,

Qualifications

• Experience with IEC 61131-3 Structured Text
• Experience with CODESYS V3 or TwinCAT environments
• Strong PLC/control software development background
• Linux experience in industrial/embedded controls environments
• Familiarity with Git workflows and code reviews
• Knowledge of object-oriented programming concepts
• Experience designing state machines and fault-handling logic
• Ability to develop reusable/modular control software
• Strong debugging and problem-solving skills
• Ability to troubleshoot hardware-software system interactions

Responsibilities

• Develop PLC/control software using IEC 61131-3 Structured Text.
• Create CODESYS V3 function blocks and reusable control components.
• Apply object-oriented programming concepts including interfaces, methods, and encapsulation.
• Design control logic using state machines with clear transitions and fault handling.
• Develop modular components reusable across material-handling systems.
• Work with Linux-based industrial PCs and controls environments.
• Use Git for source control, reviews, and collaboration.
• Debug and troubleshoot controls applications and determine root causes.
• Configure and test controls apps from electrical drawings and system requirements.
• Write and review technical requirements before development.
• Test software on hardware and address issues found during testing.
• Collaborate with controls, software, electrical, and automation engineers.

Skills

Structured Text (ST)

CODESYS

TwinCAT

PLC/software development

Linux (industrial/embedded)

Git

Object-oriented programming

State machines

Reusable/modular software

Debugging/problem solving

Hardware/software integration

Tools

Git

Job description

IMS People is seeking a Controls Software Engineer to support a next-generation material handling controls platform in a large-scale robotics and automation environment. You will develop reusable controls software using ST and IEC 61131-3, with CODESYS V3 or TwinCAT, on Linux-based industrial PCs, and collaborate across controls, software, electrical, and automation teams.

The role emphasizes greenfield development, state-machine architecture, debugging, and deployment of controls applications,