scope:

This document describes the migration that is necessary fromVersion 3.20 (CWA 16374) to Version 3.30 (this CWA). Thisspecification describes the functionality of the services providedby text terminal unit (TTU) services under XFS, by defining theservice-specific commands that can be issued, using the WFSGetInfo,WFSAsyncGetInfo, WFSExecute and WFSAsyncExecute functions. Thissection describes the functions provided by a generic Text TerminalUnit (TTU) service. A Text Terminal Unit is a text i/o device,which applies both to ATM operator panels and to displaysincorporated in devices such as PIN pads and printers. This serviceallows for the following categories of functions: ? Forms orientedinput and output ? Direct display output ? Keyboard input ? LEDsettings and control All position indexes are zero based, wherecolumn zero, row zero is the top-leftmost position. If the devicehas no shift key, the WFS_CMD_TTU_READ_FORM and WFS_CMD_TTU_READcommands will return only upper case letters. If the device has ashift key, these commands return upper and lower case letters asgoverned by the user's use of the shift key.