Method for transferring encrypted data between web server and field device in process automation system, involves generating and storing corresponding secondary key for encrypted transmission of data in web server

摘要

The method involves storing the generated primary key for encrypted transmission of data in persistent storage unit prior to the delivery of primary key to field device. The corresponding secondary key for encrypted transmission of data is generated and stored in a web server, before operating the field device in process automation system. The encrypted data is transmitted between the field device and web server based on the generated primary and secondary keys through a communication link over an Internet. An independent claim is included for access unit for wirelessly accessing process automatic system.