Operating system

The PLCnext Technology control platform is based on a Linux® operating system with the OSADL real-time patch. Linux® is a highly reliable, open source operating system suitable for applications that require a high stability. A wide range of open source software is available for the Linux® operating system, which is supported by a large community of users and developers.

You can also use this open software, software blocks, and technologies for your PLC applications (e.g. SQL server). PLCnext Technology uses a Linux® operating system and extends it by the functions of a PLC such as the cyclic processing of tasks and cycle-consistent data exchange. Core changes or extensions at the operating system are not possible.

The operating system features the following components and services:

Firewall (can be configured via the Web-based Management)
OpenVPN
IPsec strongSwan
SSH/SFTP
NTP (Network Time Protocol)
DNS

Text editors

Nano and Vim come pre-installed on the controller as text editors (Note: from firmware 2025.0, the Vim editor has been dropped for security reasons).

While you are connected to the controller via the SSH console, you can call the desired editor via the command line. To open a file with the preferred editor, enter nano <file name> or vim <file name>.

Nano

The Nano text editor is easy to use and is therefore recommended for less experienced users. Find an introduction and documentation of features at the GNU nano website.

Vim

Valid for firmware 2019.0 LTS up to 2024.6

The Vim text editor has an extended range of functions and is a popular editor in the Linux® environment. Find an introduction and documentation of features at the Vim website.

Controlling the firmware via commands

From firmware 2025.0

The plcnext service in the systemctl utitily out of the systemd Linux® suite controls the firmware.

Use the following commands:

Shell command	Description
`sudo systemctl stop plcnext`	Stops all PLCnext firmware processes
`sudo systemctl start plcnext`	Starts all PLCnext firmware processes
`sudo systemctl restart plcnext`	Restarts all PLCnext firmware processes

Firmware 2019.0 LTS to 2024.6

The plcnext script in the /etc/init.d directory controls the firmware.

Use the following commands:

Shell command	Description
`sudo /etc/init.d/plcnext stop`	Stops all PLCnext firmware processes
`sudo /etc/init.d/plcnext start`	Starts all PLCnext firmware processes
`sudo /etc/init.d/plcnext restart`	Restarts all PLCnext firmware processes