Using Configuration->Server Configuration, select the Executive (server PC name) on the left, and use the "Add TCP Route" to create the TCP/IP address reference. Make sure the address is of the form "x.x.x.x" (where x can be 0-255). Generally avoid making any digits "1" or "255" for the IP addresses for your loggers and analyzers (OK for subnet mask and gateway settings).
For most direct connections to loggers, use Port 9881 for polling and Port 9887 for emulation. You may need to make other allowances if you are going through a router and using port forwarding / network address translation (see http://www.agilairecorp.com/support/networking.htm)
If you are using a terminal server connected to a Model 8816, you will need to make the polling and emulation ports the same. This is acceptable to AirVision.
Select the "Save" icon in the upper right.
Open Configuration->Data Source Details, open the desired site, and double-click on the data logger icon.
In the right panel, select the "Communication" tab.
Under "Route", use the pull-down list (next to the "*") and select the TCP/IPRoute you created in Step 1.