AM3270 and TR3271 Configuration and Management Manual

Overview of AM3270 and TR3271

AM3270 and TR3271 Configuration and Management Manual—529993-001

2-5

Line and Subdevice Configuration

All tributary subdevices configured inside the TR3271 line are controlled by the IBM

host connected to the multipoint line. Other physical devices (3x74 cluster controllers

and their subordinates) present in the multipoint line are directly controlled by the IBM

host.

Example of Standard TR3271 Configuration

Figure 2-3, TR3271 Process Configuration shows a TR3271 process emulating a

cluster controller that have two terminals, #X1 and #X2. In the example, SCF

configures the two subdevices.

Example of TR3271 Pass-Through Configuration

PTP allows you 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 to a remote

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.

In pass-through mode, no formatting or unformatting of the buffer is performed by

either AM3270 or TR3271. All text is passed on a whole-message basis, which means

that AM3270 gathers all blocks of a multiblock message before sending it to TR3271.

Figure 2-2, Example of AM3270 Pass-Through Configuration

shows a typical pass-

through configuration used by AM3270 and TR3271.

Figure 2-3. TR3271 Process Configuration

VST003.vsd

IBM

Compatible

Host

3271

Cluster

Controller

3270

Terminals

and Printers

HP NonStop System

TR3271

$TR

(PTP)