Hi Eng Swee.
The reason why we have opted for XI adapter is that ,the SSL certificate provided by the client has to be inserted in STRUST. Only XI adapter is compatible to support this ,we cant use SOAP adapter with XI protocol.
One more point that I would like to point out is that ,we are able to send the messages successfully to the target PI system only when XPI Inspector is running with rwb option in the start mode.
Regards
Tibin