Folders and PLCnext Technology environment variables The following table lists environment variables on the controller, representing directories that are required for app administration. The values of these environment variables are set to the defaults shown below, using information in the file /etc/plcnext/Device.acf.settings. These default values do not need to be… Read More
PLCnext Technology Extensions Extensions of the runtime can be integrated into a system in the form of an app. With a PLCnext Technology Extension, the runtime can be extended by the following elements: A process dependent on the runtime (process) A component (component) A Shared Library (library), which usually… Read More
Linux Daemons The support for the Linux Daemons app part type is discarded and removed from PLCnext Technology firmware from version 2025.0. From version 2025.0, the OCI container app part type is supported in the PLCnext Technology firmware. A (Linux) Daemon can be integrated into a system in the form of an app. Read More
Metadata The app description file must contain a JSON object with the name “plcnextapp”, which describes the properties of the PLCnext Technology App: { “plcnextapp”: { “name”: ““, “identifier”: ““, “version”: ““, “target”: ““, “minfirmware_version”: ““, “manufacturer”: ““, “licensetype”: ““,… Read More
Configuration of the PLCnext Technology Runtime Services If you need access or sometimes exclusive access to PLCnext Technology System Services in your app or a PLCnext Technology System Service is not allowed to be running when your app run, you can state this in the “plcnextservices” field of the app_info.json. This is often not… Read More
File and data storage The files of an app container are unpacked into a read only filesystem mounted via SquashFS, so that the apps cannot save/store data/files in their installation directory at runtime. The app description can be used to specify whether a persistent and/or… Read More
App installation states PLCnext Technology Apps must be installed and uninstalled using either the PLCnext Store or the web-based management (WBM) hosted on the controller. In the background, both the PLCnext Store and the WBM interact with the AppManager on the controller to handle the app installation and run states. A PLCnext Technology App… Read More
Shared Libraries The support for the Shared Libraries app part type is discarded and removed from PLCnext Technology firmware from version 2025.0. It can happen that an exe file integrated in the app container, such as a Command Line Tool, brings its own Shared Libraries with it and needs them for its… Read More
Creation of an app container The Linux command plcnextapp is available under /usr/bin and is used to create an app container. The following parameters are supported: create e.g.: plcnextapp create /opt/plcnext/myapp My App example e.g.: plcnextapp example “create”: Creates a… Read More
Command Line Tools A Command Line Tools app part makes it possible to integrate functionalities (cmd tools) into a system that are usable via the command line and that can be started from a shell without specifying the full path to the tool executable binary. Necessary additions… Read More
