If you require a free, non-expiring tool that does not need a registration key, is a popular open-source alternative available on GitHub . It provides similar Modbus Master functionality without the commercial licensing restrictions.
Trial or demo versions
A registration key, also known as a product key or license key, is a unique code used to activate and validate a software product. It ensures that the software is genuine and allows the user to access all its features. modscan64 registration key portable