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
PLCnext Technology Apps A PLCnext Technology App (in the following also called “app” for short) is a collection of functionalities bundled into one large file that can be understood and executed by the PLCnext Technology Runtime System. Each app may contain multiple different parts, that provide functionalities to the system in their own… Read More
Update Configurations The update process is shown in the following figure: To update an app you need only to install the app container which contains the new app version (without uninstalling the old app version). The update is detected automatically when: An app is… Read More
App container A PLCnext Technology App is stored in a SquashFS container (see Squash FS on Wikipedia). A SquashFS container stores a folder and file structure in a single compressed file. The SquashFS containers of all installed and started apps are mounted by the AppManager in the Linux file system… Read More
App management In contrast to a classic package manager which installs the files of the application to be installed directly in the Linux file system, PLCnext Technology Apps are hosted in file containers (like a zip file) and the system references the files in the container. This procedure allows… Read More
