CODESYS on a Raspberry Pi: install, licence and a first program

A Raspberry Pi running the CODESYS runtime is a real IEC 61131-3 controller. You program it from the CODESYS Development System like any other CODESYS target, and the runtime package includes Modbus TCP and serial, EtherNet/IP, PROFINET, EtherCAT, CANopen and J1939 stacks, a full WebVisu and an OPC UA server. It is the cheapest way to learn CODESYS on hardware.

It is not a licence to build machines, and the install has changed enough over the years that many guides describe menus that no longer exist. This one follows the CODESYS Store page and the CODESYS online help as they stood in October 2026, for runtime version 4.22.0.0, released on 17 August 2026.

What you need

SL, MC SL or 64 SL: which runtime

The package contains three runtimes. When you install, Deploy Control SL detects the Pi's hardware and operating system and picks the matching binary; you can change it later on the Operation tab, and the tool will not let you choose an incompatible one. From the CODESYS help:

In the project there is a single device description for 64-bit systems, and whether its multicore functions are enabled depends on the licence. Each licence from CODESYS Store International lets you use either the 32-bit or the 64-bit application. The Pi Zero does not appear in the help's table, although the store page mentions it.

Two version facts from the store's history save debugging time: the full 64-bit runtime arrived in 4.10.0.0, and Raspberry Pi 5 support in 4.11.0.0. An old package on a new Pi is the first thing to rule out.

Prepare the Pi

1. Write Raspberry Pi OS to the card following Raspberry Pi's own instructions, and boot it.
2. Enable the SSH server and check it is running. The CODESYS help gives these commands; the status should show active (running).

sudo systemctl enable ssh
sudo systemctl status ssh

1. Find the Pi's address with ip a s on the Pi, or leave it to the scan in the Deploy tool.
2. Optionally run sudo raspi-config to expand the file system or give the Pi a unique host name.
3. If you will use I2C, SPI or 1-Wire devices, the help says to make sure these lines are present and not commented out in /boot/config.txt:

dtparam=i2c_arm=on
dtparam=spi=on
dtoverlay=w1-gpio-pullup,pullup=1

Install the runtime with Deploy Control SL

1. In the CODESYS Development System, open Tools > CODESYS Installer, choose Browse under Add-ons and install the CODESYS Control for Raspberry Pi SL package. That brings the runtime package, libraries, device descriptions and sample projects onto the PC. The help lists the CODESYS Control SL Deploy Tool as the other package you need.
2. Open Tools > Deploy Control SL. On the Communication tab, enter the Pi's IP address or click Scan, set the SSH port, and log in with the user name and password you set when you imaged the card, or with a public key. The help's table of default credentials still lists pi and raspberry.
3. On the Deployment tab, choose the product and version and click Install. The runtime is installed and the controller restarts by itself.
4. On the Operation tab, check the runtime is running; Start Selected starts it if it is not.

Older guides, including the community wiki on CODESYS Forge, describe a Tools > Update Raspberry Pi command. The current help uses Tools > Deploy Control SL, and the store's version history records a reworked SL Deploy Tool in 4.14.0.0. If your menus do not match a tutorial, check the tutorial's date before you check your installation.

The licence and the two-hour limit

Without a licence the runtime runs for two hours without functional limitations and then shuts down. A manual restart is needed to continue.

Everything else the store page says about licensing, in short:

• Use. The combination of a Raspberry Pi and a CODESYS runtime is for private use, test and teaching. Commercial use is not permitted; for a device used commercially, the store points to application-based licences.
• Where it may run. Not released for containers or virtual machines.
• Licence type. A single-device licence. It is activated into a soft container that is permanently tied to the controller, or onto a CODESYS Key USB dongle, which can be moved to another controller by plugging it in there.
• Price. EUR 55 plus VAT on CODESYS Store International at the time of writing (October 2026). Technical support is not included; it is sold separately as a support ticket.

To activate a licence, the help's procedure is: create a standard project, update the device in the device tree, open Tools > License Manager, choose Device and then Dongle or Soft Container, select the Pi, choose Install Licenses, then Activate License and enter the ticket ID. The PC needs internet access and a connection to the Pi. A soft-container licence is locked to that device at activation, so decide whether a dongle suits you better before you activate. Since 4.13.0.0 the runtime also supports network licensing through the CODESYS License Server for Linux SL.

The two-hour limit matters in one practical way: when the runtime shuts down, nothing wired to the Pi is being controlled any more. Do not leave a demo runtime in charge of anything that has to keep running.

A first program

The help's first test is a counter. Choose File > New Project > Standard Project, pick the Raspberry Pi device that matches the runtime you installed, and CODESYS creates an application with a PLC_PRG program called by a task named MainTask.

PROGRAM PLC_PRG
VAR
  iCount : INT;
END_VAR

iCount := iCount + 1;

To download it, double-click the device in the device tree, open the Communication Settings tab, click Scan Network, select the Pi, then Online > Login, accept the download and start the application. If the counter climbs in the monitoring view, the whole toolchain works.

If the scan finds nothing, the help points to the network first: by default the connection uses UDP, so the PC and the Pi must be in the same subnet with the same network mask. It also suggests switching off Filter Network Scans by Target ID under Device > Options; if the Pi then appears, its target ID is wrong.

Something that drives an output

Next, a start/stop circuit with a seal-in, the pattern every motor starter uses:

PROGRAM PLC_PRG
VAR
  xStart : BOOL;   // momentary push button, normally open
  xStop  : BOOL;   // normally closed, TRUE while healthy
  xRun   : BOOL;   // drives a relay module
END_VAR

xRun := (xStart OR xRun) AND xStop;

The GPIO.project sample that comes with the package shows how pins are wired into a project: a GPIOs device whose editor configures the I/O image and defines which pins are inputs and which are outputs. Inputs and outputs each appear as a DWORD, and bit X holds GPIO X; the sample flashes GPIO18 as an output. Map xStart and xStop to input bits and xRun to an output bit. For the B+ and Pi 2 layout, the help says to switch from the GPIOs A/B device description to GPIOs B+/Pi2 with Update Device, and it warns that some GPIOs may be permanently assigned to other functions by loaded drivers.

Raspberry Pi's own documentation gives the GPIO levels as 0 V and 3.3 V. A 24 V push button or contactor coil needs an interface between it and the pin, such as an opto-isolated input board or a relay module, never a direct wire.

Drawing the logic first

If you think in ladder, the free LADX ladder editor lets you draw and simulate the rung scan by scan before you touch the Pi. LADX Convert, which has the same start/stop circuit among its examples, writes a program as IEC 61131-3 Structured Text, which you can paste into PLC_PRG, or as PLCopen XML for CODESYS's Import PLCopenXML command in the Project menu. It reports anything it could not translate, and its PLCopen output carries the logic as Structured Text rather than as ladder graphics, which it also states. Structured Text for ladder programmers explains the mapping.

What goes wrong

When a Pi is the wrong answer

The CODESYS help is plain about it: the Raspberry Pi was developed for testing and teaching, and industrial use is not recommended. For learning CODESYS, trying a fieldbus or a home project it is good value. For a machine, the licence terms rule it out before the hardware does, and PLC or microcontroller covers what else changes. For an open-source runtime on the same board, see open source PLC options. For CODESYS on general-purpose hardware in a real system, virtual PLCs explains that route.