Recently, surfing on the web, I found for an industrial automation software house located in Italy: Axel Software.

I had the chance to test their IEC61131-3 development environment, Logic Lab: free , powerful and lightweight (installation package about 28MB)

LogoLogic Lab

I tested for the version Using it I get a good surprise: it permits to develop Arduino Due and Raspberry Pi (B,B+,2) applications


Moreover, regarding the Pi, Axelsw shares a pre-formatted Raspian Image (to be installed into a common SD card , using Win32DiskImager) with a  100% free (no demo o time-limit) softPLC runtime called LLExec.

Here some extract from "LLExec RaspberryPI HOWTO" text guide: (attached the complete file)

LLExec RaspberryPI HOWTO

Following these instructions, you can turn your Raspberry PI B or B+ into a 
complete IEC-61131 PLC.

0) Hardware Setup
The LLExec PLC runtime has been tested on Raspberry PI Model B and B+,
Raspberry PI 2 model B and Raspberry PI 3 model B,
with I/O expansions PIFace or PIFace Digital 2, depending on the model of 
Raspberry PI.
The runtime PLC runs even without I/O expansion, it can be used to drive
standard fieldbus modules, following the Modbus TCP standard.
It also requires an SD or uSD at least 8GB to program the modified Raspbian 

0.1) Software Setup
You can proceed in two alternative ways:
- 1) program a SD or uSD card with a full Raspbian image, already configured 
     to run LLExec PLC runtime.
- 1/b) install LLExec PLC runtime on a standard Raspbian image.
Follow one of the two options, then go to section 2) Get the free license

Here follow, how to turn your Pi into a 100% working PLC:

  • Download the Raspian Image patched with LLexec runtime from here
  • Download LogicLab tool suite from Axelsw website
  • Install LogicLab suite (it take a minute) in your Windows PC


  • Prepare a bootable SD card for the Pi: unzip the Raspian Image patched with LLexec then write it to the SD card with Win32DiskImager
  • Run the Pi, then login with PuTTY using the credential: user: pi  passw: axel


  • The Axelsw Raspian image is not licensed by default: this means you cannot connect online, download project,.... Need to retrieve the license key file as described into the "LLExec RaspberryPI HOWTO" guide
2) Get the free license
Login as user "pi", password "axel"
and acquire root privileges with the command "sudo -s"

Stop the LLExec process, if running, with the command
/etc/init.d/LLExecDaemon stop

Change to the directory /data/plc and issue the command
./LLExec -tm -1

It prints a series of logs that will end with these last lines
GetHardwareIDs returned 1
   HardwareID 0: 8ade035e7521fca1
Error reading current license key
!! License key is invalid or missing
LLEXEC main finished

Send a mail to This email address is being protected from spambots. You need JavaScript enabled to view it. with the HardwareID of your device (in this 
case 8ade035e7521fca1)
Axel will send you the LLExec.key file related to your hardware.
Install the license overwriting the file in the directory /home/pi/plc with 
the one sent by Axel and reboot the system,
The PLC should be started, you can now download out lates LogicLab automation
suite, and connect to your target.
  • Install the LLExec.key into the /data/plc directory, then reboot and the Pi is ready to run
  • Open the LogicLab suite, then create e new empty project based on Raspberry target (v.1.0)



  •  then create task , function, logic as a usual 61131-3 IDE.


  • In my sample I also add a Master Modbus. Into the "Resources", "Ethernet" flags the "Modbus TCP Master"


  • Then "Add" a generic Modbus node (slave) and configure it (IP addr,...)




  • Add some Modbus functions (ex. Read Hoding Registers, Write,...) and link address to the project internal variables

LogicLabIDE6    LogicLabIDE7


  • Read


  • Write


 Rebuild, download the go online and enjoy it!