Core components of the PLCnext Technology

PLCnext Technology is an open firmware platform executed on a Linux operating system with real-time patch. Different firmware components forming the core functions are called core components. These core components are a fixed part of the PLCnext Technology firmware. They cannot be modified. The core components are divided into the following groups: 

  • Middleware
  • I/O components
  • Service components
  • System components


The middleware section decouples the PLCnext Technology firmware from the operating system. The Global Data Space (GDS) is part of the middleware and is responsible for a central function of PLCnext Technology. It enables consistent data exchange between different real-time components. For additional information on the GDS, please refer to the GDS section.

I/O components and Fieldbus Manager

The fieldbus manager connects the implemented fieldbus to PLCnext Technology for input and output of process data. The following fieldbusses are supported (depending on the PLCnext Control device):

  • PROFINET® controller
  • PROFINET® device
  • Axioline F master (local bus)
  • INTERBUS master (with PLCnext Control AXC F 2152 or AXC F 3152 and additional extensions, e.g. AXC F IL ADAPT and AXC F XT IB)
  • PROFIBUS® master (with PLCnext Control AXC F 2152 or AXC F 3152 and extensions AXC F XT PB)

Service components

The service components provide access to the ESM (Execution and Synchronization Manager), GDS (Global Data Space) and to the following system components:

  • OPC UA server
  • PROFICLOUD gateway
  • Web-based management
  • HMI web server (HTML5 web visualization in PLCnext Engineer)
  • Accessible via Linux:
    • SFTP
    • VPN
    • SSH
    • NTP
    • Trace controller

System components

In the system components, all basic functions of PLCnext Technology are implemented.

  • System Manager and PLC Manager
    These components load all the other system components and monitor the stability of the system.
  • ESM (Execution and Synchronization Manager)
    The ESM enables IEC 61131-3, C++ and MATLAB® Simulink® programs to be executed in real time. For creating applications, programming languages can be combined in any way. For additional information on ESM, please refer to the ESM section.
  • User manager
    The user manager extends the standard Linux user management function. The various user roles are managed here. You can only execute operations in the PLCnext Technology firmware with a defined user role. You can select one or more user roles with different permissions for each user.
  • IEC 61131 runtime
    ProConOS embedded CLR is the open IEC 61131 control runtime system for different automation tasks from Phoenix Contact.

Real-time user programs

User programs are not supplied as a standard with the PLCnext Technology firmware; they are created by the user. These user-defined programs can be created in classic programming languages in accordance with IEC 61131-3, and also in C++ or Matlab® Simulink®. It is also possible to combine different programming languages.
The easiest way to use PLCnext Technology is to create user programs in programming languages in accordance with IEC 61131-3, in C++ or using MATLAB®/Simulink®, and to execute these in the real-time environment of the ESM. The user programs are downloaded to the controller and, after a cold restart of the device, are executed by the firmware.

The IN and OUT ports of the GDS guarantee data consistency and ensure seamless data exchange between tasks and programs:



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