Using a stand-alone PLC project

A stand-alone PLC project manages a conventional PLC project (PLC project embedded in the TwinCAT project) in a separate project type. Programming is the same as for an embedded PLC project. In contrast to this, the PLC instance is not directly available in the project, but can only be configured within the TwinCAT project after integration. The TwinCAT 3 type system is also available in the stand-alone PLC project for managing project-based data types or configuring the TwinCAT 3 event logger.

Stand-alone PLC projects thus make it possible to separate system, motion and I/O configuration from PLC development at project level. This results in two separate projects: the stand-alone PLC project and the TwinCAT project.

The two projects can be managed in a common solution or in separate solutions. In order to link the PLC module instance in the TwinCAT project with the associated components at system, motion and I/O level, the TMC file compiled in the stand-alone PLC project is integrated.

This procedure enables, for example, the strict separation of system configuration and PLC programming, the integration of a PLC instance into different system configurations or the download of the PLC project runtime data under certain conditions from the PLC project without exception.


Stand-alone PLC projects can be used from TwinCAT version 3.1.4022.0.

See also:

Creating a standard project
Documentation C/C++ > Appendix > Type system
Additional information
Creating a stand-alone PLC Project
Integrating the stand-alone PLC project into a TwinCAT project
Best practice