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
PLCnext Technology App Integration Guide Learn all about creating apps for the PLCnext Store in this PLCnext Technology App Integration Guide. 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… 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
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
License check In case of a chargeable app a license check should be integrated into the app. For this purpose the RSC service Arp::System::Lm::Services::ILicenseStatusService::GetLicenseStatus(uint32 firmCode, uint32 productCode, uint32 featureCode=0) is available. See the RSC documentation reference in the main PLCnext Technology Info Center. This function is integrated in… Read More
Building a PLCnext Technology App Independent of the amount and types of your app parts the general way to build the app is always identical. The necessary changes you need to include for every app part will be detailed below the general build process. The description of each app… Read More
Alternative creation of an app container on a Linux desktop PC In some cases the command plcnextapp cannot be used for generating the app container, e.g. because this creation step should be integrated into a build process which cannot access a PLCnext Control. In this case the SquashFS of the app… Read More
Diagnostic log files All status and error information related to app management are saved in the following two log files: /opt/plcnext/logs/Output.log: All status and error messages of thePLCnext Technology firmware, including those of the app management components /opt/plcnext/logs/plcnextapps.log: status and error messages of the plcnextapp command line tool… 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
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
