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http://IP-address:port/web2/product/version
GET http://127.0.0.1:8085/web2/product/version
The response is text/plain line like:
Axxon PSIM/1.0.2875
It means that the server supports the protocol described in this document. The line can change depending on the product version. This helps to distinguish 2 web servers with similar functionality but different protocols in different products.