DS CWA 16374-68:2012 Extensions For Financial Services (Xfs) Interface Specification Release 3.20 - Part 68: Text Terminal Unit Device Class Interface Migration From Version 3.10 (Cwa 15748) To Version 3.20 (This Cwa) Programmer's Reference Explains the functionality of the services provided by text terminal unit (TTU) services under XFS, by defining the service-specific commands that can be issued, using the WFSGetInfo, WFSAsyncGetInfo,