2. Text Terminal Unit

This specification describes the functionality of the services provided by text terminal unit (TTU) services under WOSA/XFS, by defining the service-specific commands that can be issued, using the WFSGetInfo, WFSAsyncGetInfo, WFSExecute and WFSAsyncExecute functions.

This section describes the functions provided by a generic Text Terminal Unit (TTU) service. A Text Terminal Unit is a text i/o device, which applies both to ATM operator panels and to displays incorporated in devices such as PIN pads and printers. This service allows for the following categories of functions:

• Forms oriented input and output

• Direct display output

• Keyboard input

• LED settings and control