When changing the Industrial PC, you can apply to have the TwinCAT licenses transferred to the new PC. You can find a detailed description of how to change the licensing basis in this tutorial.
You can find the request for the license transfer here: TwinCAT 3 licensing
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TwinCAT
The TwinCAT software system turns almost any PC-based system into a real-time control with multiple PLC, NC, CNC and/or robotics runtime systems.
TwinCAT 3 licensing
TwinCAT 3.1 offers the option of using a TwinCAT 3 license key (license dongle) for licensing.