AM3270/TR3271 Reference Manual

Overview

A Closer Look at TR3271

5–2 086705 Tandem Computers Incorporated

For specifics about configuring and using TR3271 subdevices, refer to the SCF Reference

Manual for AM3270 and TR3271.

Examples The following two figures show two typical TR3271 configurations, one standard and

one pass-through. For a more complex version of these figures, refer to the figure in

Section 6, “TR3271 Subdevice Protocols.”

Standard Configuration

Figure 5-1 shows a TR3271 process emulating a cluster controller with two terminals,

#X1 and #X2. In the example shown in this figure, SCF must be used to configure the

two subdevices.

Figure 5-1. TR3271 Standard Configuration

017

Tandem NonStop System

$TR

3270 Terminals

and Printers

IBM

Compatible

Host

3174/3274

Cluster

Controller

TR3271

(PTP)

Pass-Through Configuration

The Pass-Through (PTP) protocol provides the ability to logically connect a TR3271

emulated subdevice directly to an AM3270 subdevice without an intervening

application process. This capability is normally used to attach 3270 terminals and

printers controlled by AM3270 directly to a host system.

Data received from the IBM host for a TR3271 pass-through subdevice is sent to the

corresponding AM3270 subdevice. AM3270 selects the device, writes the data, and

completes the request to TR3271. TR3271 then posts another READ on behalf of the

AM3270 subdevice.