CODESYS · Engineering

CODESYS Development System

IEC 61131-3 Engineering Environment for Industrial Control Applications
CODESYS Development System is the core engineering environment for creating industrial control applications. It combines IEC 61131-3 programming, device and I/O configuration, libraries, compilation, debugging and online commissioning in one project. The application is engineered here and executed later by a compatible CODESYS runtime.

Device and I/O configurationOnline debuggingLibrary managementSimulationPLCopen XML
CODESYS Development System official product image
StandardIEC 61131-3
Maintained editorsST · FBD · LD · SFC
RoleEngineering & commissioning
ExecutionCODESYS Runtime / Control target
Product role

IEC 61131-3 engineering environment for the control application

CODESYS Development System is the core engineering environment for creating industrial control applications. It combines IEC 61131-3 programming, device and I/O configuration, libraries, compilation, debugging and online commissioning in one project. The application is engineered here and executed later by a compatible CODESYS runtime.

Integrated application engineeringControl logic, device configuration, libraries, communication, and supported visualization or motion extensions can be engineered within one CODESYS project.
Target-aware build processThe selected device description and compiler configuration determine how the project is built for the target controller and runtime.
Online diagnostics and commissioningBreakpoints, variable monitoring, traces, project comparison and other online functions support commissioning and troubleshooting on compatible targets.
Architecture role

From engineering project to target controller

Define the interfaces and ownership boundaries first; version, licence and target selection should follow the architecture rather than lead it.

01Machine requirement
02CODESYS Development System
03Device / I/O configuration
04Compile & debug
05CODESYS Runtime target
Confirm the exact target, product version, device package, protocol role, licence and—where applicable—certified safety scope before release to production.
Engineering scope

Core engineering and commissioning capabilities

These capabilities define what the CODESYS component contributes to the architecture and what must still be provided by the controller, host platform, network or machine design.

01

Integrated application engineering

Control logic, device configuration, libraries, communication, and supported visualization or motion extensions can be engineered within one CODESYS project.

02

Target-aware build process

The selected device description and compiler configuration determine how the project is built for the target controller and runtime.

03

Online diagnostics and commissioning

Breakpoints, variable monitoring, traces, project comparison and other online functions support commissioning and troubleshooting on compatible targets.

Technical selection

Controller, device-package and version compatibility

Use this table as a requirement-capture guide. The final implementation should be checked against current CODESYS product documentation, Store data, target documentation and—where relevant—certificates and safety manuals.

Programming languagesStructured Text (ST), Function Block Diagram (FBD), Ladder Diagram (LD) and Sequential Function Chart (SFC) are core maintained IEC 61131-3 editors. CFC is available as an additional graphical engineering option.
Instruction List (IL)IL is marked obsolete by PLCopen and is not maintained as a primary language. It can be enabled where legacy projects require it.
Object-oriented engineeringCODESYS supports IEC 61131-3 third-edition object-oriented concepts including methods, interfaces, inheritance and encapsulation.
Engineering scopeProject and device configuration, libraries, fieldbus configuration, compilation, project comparison, simulation where applicable, debugging and online diagnostics.
Target compatibilityThe controller device package, compiler profile and runtime version must match the actual target. Manufacturer-specific device packages are often required.
Commercial scopeThe Development System itself is available from CODESYS; optional add-ons, runtime products and target-specific licences are scoped separately.
Project workflow

Recommended engineering and commissioning workflow

Move from architecture qualification to engineering, commissioning and lifecycle evidence in a controlled sequence.

01

Qualify the target first

Confirm the controller, runtime generation, device package and required protocol options before creating the production project.

02

Define the software architecture

Structure tasks, POUs, interfaces, libraries, diagnostics and naming conventions before application growth makes refactoring costly.

03

Commission against real hardware

Use simulation where useful, then verify I/O, timing, communication and restart behaviour on the selected controller.

04

Freeze a recoverable baseline

Archive the project together with libraries, device packages, compiler/runtime information and deployment records.

Documentation & requirement capture

Official CODESYS documentation and project inputs

Use the official product page for current product information, then provide the project-specific details below so the architecture can be reviewed against the actual machine or system.

Application scopeMachine/process functions, operating modes, cycle-time expectations and whether the project is new design, retrofit or migration.
Target & software baselineController/IPC, CPU architecture, operating system, CODESYS runtime, device package, compiler profile and existing project version.
I/O & communicationLocal/remote I/O, fieldbuses, Industrial Ethernet, OPC UA, MQTT, controller-to-controller links and required protocol roles.
HMI & user accessDisplay hardware, browser clients, independent HMI requirements, alarms, trends, recipes, user roles and remote-service policy.
Motion & functional safetyAxis count, drives, kinematics, CNC/robotics requirements, safe I/O, safe communication and required PL/SIL where relevant.
Deployment & lifecycleController quantity, sites, licensing, backups, certificates, update process, rollback expectations and maintenance ownership.