How to Create Visualization in CODESYS: PLC Programming Tutorial for Beginners (2026)

How to Create Visualization in CODESYS: PLC Programming Tutorial for Beginners (2026) (Updated November 2026)

CODESYS visualization lets you build a software-based operator interface directly inside your PLC program — no separate HMI hardware needed. For engineering students, automation trainees, and PLC beginners working on Beckhoff, Phoenix Contact, Wago, or Raspberry Pi-based CODESYS controllers, this is the skill that takes your programs from text-only logic to interactive visual panels. This tutorial walks through the complete process of creating a CODESYS visualization: adding visualization objects, wiring start and stop buttons to PLC variables, adding a lamp to monitor output status, and running the program in Online Visualization mode. The ABC Trainings YouTube tutorial video is embedded above — this article supplements it with written steps and explanations.

What Is CODESYS Visualization and Why Do PLC Programmers Use It?

CODESYS visualization is a built-in feature of the CODESYS development environment that lets you design graphical operator panels directly within your PLC project — without additional SCADA software or a physical HMI panel. It uses a drag-and-drop editor where you place visualization objects (buttons, lamps, sliders, display fields) and then link each object's behaviour to a variable in your PLC program. When you switch to Online Visualization mode after downloading the program to the PLC, the visualization runs live — button clicks change variable values, and the lamps and indicators update in real time based on your program logic. CODESYS visualization is the standard training tool at PLC courses worldwide because it makes PLC program logic visible and testable without expensive hardware. In India's automation sector — at Beckhoff TwinCAT panels, Wago I/O systems, Phoenix Contact PLCs, and all CODESYS-runtime–based controllers increasingly adopted at MIDC industrial plants — CODESYS visualization skills are directly transferable to HMI programming. The concepts you learn in CODESYS visualization (linking UI elements to variables, configuring button event actions) apply directly to SCADA and HMI development on Siemens WinCC, Wonderware, and FactoryTalk systems.

How to Add a Visualization Object in CODESYS

To add a visualization object in CODESYS, open your PLC project and navigate to the Application tree in the Solution Explorer. Right-click on Application → Add Object → Visualization. This creates a new Visualization page (VISU_0 by default). Double-click the Visualization object to open the graphical editor. In the Toolbox panel on the right, you will find categories of visualization elements: Basic Shapes, Input/Output, Controls, and Lamps and Displays. To place an object, drag it from the Toolbox onto the canvas. A properties panel appears on the right — each property maps to a CODESYS expression or variable address. For your first visualization page, set a sensible name (e.g., Main_Panel) and confirm the canvas size matches your target display resolution. The visualization is saved as part of your CODESYS project and will be available online after you download the PLC program.

Visualization Element	Purpose	Key Property to Link	Typical PLC Variable
Switch (Start)	Momentary start command	Variable (tap)	GVL.bStart
Push Button (Stop)	Momentary stop command	Variable (press)	GVL.bStop
Lamp	Visual output status indicator	Variable (boolean)	GVL.bMotorRun
Text Display	Show variable value	Text Expression	INT_TO_STRING(GVL.nCounter)

Configuring Start and Stop Buttons in CODESYS Visualization

To add a Start button, drag a Switch element from the Toolbox onto the canvas. In the Switch properties, find the Variable field — click the ellipsis and navigate to your PLC program variable for the start command (e.g., GVL.bStart or xStartCmd depending on your variable declaration). Under Tap Behavior, set Toggle off and Gesture Type to Tap — this makes the button send a single pulse (TRUE while held) rather than a latching toggle, which is the standard momentary start button behaviour in motor control circuits. To add a Stop button, use the same process with a Push Button element — link it to your stop variable (e.g., GVL.bStop or xStopCmd). Set the button's visual label text to START and STOP respectively using the Text property. Use contrasting background colours for the buttons — green for Start, red for Stop — to follow IEC 61131 panel colour conventions. Both buttons must reference correctly declared PLC variables; undeclared or mistyped variable names will cause a build error.

Linking Visualization Elements to PLC Program Variables

After placing your buttons, click on each visualization element and open its Properties panel. The Variable or Expression field accepts standard CODESYS variable addressing — for example, GVL.bStart for a global variable, or .bStart if your visualization references a function block instance. To link a lamp or an indicator text display, use the same Properties panel. For a button, the key property to link is the Variable address for the tap/press action. For a text output display, link the Text Expression property to the variable you want to display (e.g., INT_TO_STRING(GVL.nCounter) to display a counter value). After linking, use the Online Code View (in the Build menu) to verify that all variable paths resolve without errors before downloading. CODESYS will flag unresolved variables with a red exclamation mark in the visualization editor — fix each one before going online, as unlinked elements will not respond during the online test.

Adding a Lamp to Monitor PLC Output Status

A Lamp element in CODESYS visualization shows the real-time ON/OFF state of a PLC output variable — it is the most common way to monitor motor running status, valve open/closed state, or any boolean output in a test visualization. To add a lamp: drag a Lamp element from the Toolbox onto the canvas. In the Lamp properties, find the Variable field and link it to your output variable (e.g., GVL.bMotorRun, Q0.0, or the output bit of a function block). Under Color settings, set the ON Color (typically green for running, red for fault) and OFF Color (grey or dark). You can also add a label to the lamp using a Text element placed adjacent to it — use a Static Text or linked Text property. Once configured, the lamp will glow with the ON color whenever your linked variable is TRUE in the running PLC program, and revert to the OFF color when the variable goes FALSE — giving you a live visual indication of your output state without any hardware indicator.

Running Online Visualization Mode and Testing Your CODESYS Program

After linking all visualization elements to PLC variables, download the program to the PLC controller (or CODESYS SoftPLC on PC) using PLC → Login with download. Once logged in, select Debug → Start to run the program. To switch to the live visualization, click Online → Visu (or double-click the Visualization object in the Solution Explorer while online). The visualization panel opens in Online Visualization mode — all linked elements are now live. Click your Start button — your PLC start variable should go TRUE, the program logic should run, and the output lamp should change colour. Click Stop — the output should go FALSE and the lamp should return to its OFF state. If a button does not respond, check that the variable address in the Properties panel exactly matches the declared variable name including case. If the lamp does not change colour, verify that the PLC output variable is being set to TRUE by the program logic during the test — check the program view in online mode to see variable values in real time. This complete cycle — button press → PLC variable change → program execution → output lamp update — is the foundation of all CODESYS HMI and visualization development.

CMYKPY 2026 pays ₹6,000–₹10,000/month during PLC SCADA and automation training at ABC Trainings — a CMYKPY-empanelled centre. Courses cover CODESYS, Siemens STEP 7 / TIA Portal, Allen Bradley, and HMI development. Call 7039169629 at Hadapsar (Pune), Cidco or Osmanpura (Sambhajinagar) to register.

FAQs

What is CODESYS visualization and what can it do?

CODESYS visualization is a built-in graphical panel editor in the CODESYS development environment that lets you create operator interface screens — buttons, lamps, display fields — directly inside your PLC project. Each visual element links to a PLC program variable. When the program is running on the controller, the visualization shows live variable states and lets the user interact with the running program through button clicks and input fields, without needing a separate physical HMI.

How do I create a start/stop button in CODESYS visualization?

To create a start button in CODESYS visualization: drag a Switch element from the Toolbox onto the visualization canvas. In the Switch properties, set Variable to your start command variable (e.g., GVL.bStart). Set Tap Behavior to a momentary action (not toggle). For the stop button, use a Push Button element linked to your stop variable. Set contrasting colours: green for Start, red for Stop, per IEC 61131 convention. Both buttons must link to declared PLC variables.

Can CODESYS visualization replace a physical HMI for PLC programs?

CODESYS visualization can replace a physical HMI for training, testing, and small-scale automation — it runs directly on the CODESYS SoftPLC or a CODESYS-runtime–based controller and provides full button/lamp/display functionality. For production environments with operator safety requirements, a hardened physical HMI is still required. For educational use and lab testing at ABC Trainings, CODESYS visualization runs the full cycle: start/stop control, output monitoring, and counter/status display without any hardware HMI.

Does ABC Trainings PLC SCADA course include CODESYS programming?

Yes — ABC Trainings PLC SCADA courses at Hadapsar (Pune), Cidco and Osmanpura (Sambhajinagar) cover CODESYS programming as part of the industrial automation curriculum alongside Siemens TIA Portal, Allen Bradley Studio 5000, and HMI/SCADA development. CMYKPY government stipend (₹6,000–₹10,000/month) is available at all centres for eligible Maharashtra students. Call 7039169629 or WhatsApp 7774002496 to confirm current batch and course scope.