Managing components

PLCnext Technology is based on components that are included via theIComponentInterface interface (see IComponent and IProgram). 

ACF - Application Component Framework

The Application Component Framework (ACF) is a part of the System Manager and manages the function extensions. The ACF is a framework that enables component-based platform development and configurative composition of the firmware for different devices. It enables dynamic and configurative integration of user functions into the system. The components managed by the ACF are thus firmware components and user components that are executed independently of the PLC program. The ACF generates the components when booting the firmware. 

For additional information on the ACF, see the specific ACF topic.

PLC Manager and Program Library Manager

One firmware component that is managed by the ACF is the PLC Manager. It manages the PLC program (real-time user program). The associated components and libraries that make these user programs available are managed by the PLC Manager via the Program Library Manager (PLM). The configuration is executed with a file referenced by /opt/plcnext/projects/Default/Plc/Plm/*.Plm.config. The PLC Manager generates the components when loading the program.

For additional information on the PLC Manager and Program Library Manager, please refer to section PLC Manager and to IComponent and IProgram.

Delimitation of ACF and PLM



  • Only components that are managed via PLM can make programs available that can be instantiated in ESM tasks (IProgramProvider).
  • Only components that are managed via the PLM can be stopped, modified and started up via download from PLCnext Engineer. This is also the case for ESM tasks and the programs instantiated therein. 
    For components that are managed via the ACF, the firmware must be stopped, the changed component must be refreshed, and after that the firmware must be rebooted.
  • Only components that are managed via the ACF are retained, even if the PLC program is shut down, deleted or booted.




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• Published/reviewed: 2022-09-14 • Revision 046 •