The Xi Test client is designed for application level tests of Express Interface (Xi / OPC .NET) servers.
It's easy to install and use.
The test client is built with the Advosol PaXi Client Base.
The test client can access OPC .NET (Xi) servers, OPC Classic DA/AE/HDA servers and OPC UA servers. It does most server access asynchronously and doesn't become unresponsive due to slow server access.
OPC UA server access needs proper configuration and a certificate. Documentation and utilities are part of PaXi but are not included in the test client download. Download the PaXi evaluation instead.
Advosol offers the test client as a free tool for Xi application developers.