SNAX/APN Application Programming Manual

SNAX/APN Application Programming Manual—420111-001
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The ITI Interface
The interactive terminal interface (ITI) is implemented through the ITI protocol.This
section describes the ITI protocol, which supports conversational mode (line-at-a-time)
communication with SNA 3270-type display terminals. In the next subsections, you
will find the following information:
•
How to use the ITI protocol
•
Sending and receiving data
•
Operational characteristics of the ITI protocol
•
Functions available with the ITI protocol
How to Use the ITI Protocol
The ITI protocol supports conversational communication between an application process
residing on a Tandem NonStop system and an SNA 3270-type terminal on a separate
IBM subarea network. The ITI protocol can be used by any application process running
in conversational mode on a Tandem system.
The Tandem Advanced Command Language (TACL) interpreter is an example of such
an application as is the File Utility Program (FUP). You start FUP at the TACL
command; FUP then communicates with a terminal through ITI.
Figure 3-1 shows the generalized case. Applications can use the ITI interface to
SNAX/APN, which provides the lower-layer access method into the SNA network and
out to a selected device.
Figure 3-1. Typical Subsystem Use of the ITI Protocol
301CDT .CDD
Device
User
Application
User
Application
SNAX/APN
ITI
Tandem NonStop System
SNA Subarea Network