CWA 14923-4:2004

This document describes the Text Input / Output Device Class ( TIO ) based on the basic architecture of J/XFS which is similar to the JavaPOS architecture. It is event driven and asynchronous.
Three basic levels are defined in JavaPOS. For J/XFS this model is extended by a communication layer, which provides device communication that allows distribution of applications and devices within a network. So we have the following layers in J/XFS:
• Application
• Device Control and Manager
• Device Communication
• Device Service
Application developers program against control objects and the Device Manager which reside in the Device Control Layer. This is the usual interface between applications and J/XFS Devices. Device Control Objects access the Device Manager to find an associated Device
Service. Device Service Objects provide the functionality to access the real device (i.e. like a device driver).
During application startup the Device Manager is responsible for locating the desired Device Service Object and attaching this to the requesting Device Control Object. Location and/or
routing information for the Device Manager reside in a central repository.
To support Text I/O Devices, the basic Device Control structure is extended with various properties and methods specific to this device which are described on the following pages.