AM3270/TR3271 Reference Manual

TR3271-Specific Operations
A Closer Look at TR3271
086705 Tandem Computers Incorporated 5–3
In pass-through mode, no formatting or deformatting 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 5-2 shows a typical TR3271 pass-through configuration. In the illustration
terminals t1 and t2 have their data passed through AM3270 and TR3271 to the host.
Figure 5-2. TR3271 Pass-Through Configuration
AM3270
Comm Line
TR3271
x1
x2
(PTP)
(PTP)
Tandem NonStop System
Comm Line
IBM
Compatible
Host
018
3270 Devices and Controller
(CRT)
(Printer)
t2
t1
t2
t1
Subdevices This section discusses the ways in which TR3271 accesses subdevices. For a detailed
description of how to configure TR3271 subdevices, refer to the SCF Reference Manual
for AM3270 and TR3271.
Configuration and Control
of Emulated Subdevices
As with AM3270, SCF is the only Tandem utility program that provides a
conversational and programmatic interface to emulated TR3271 subdevices in both a
C30.09 and D-series 3650/6100 CSS environment. For information about using SCF
commands with TR3271, refer to the SCF Reference Manual for AM3270 and TR3271.
Note The Communications Management Interface (CMI) can also be used for C-series releases, but it has less
functionality than SCF, and Tandem recommends that you use SCF. Support for the CMI interface and
the 6202 controller are discontinued for AM3270 and TR3271 for the D-series releases.
Level 4 Protocols The two level 4 (subdevice) protocols for TR3271 are:
CRT for standard CRT-display mode.
PTP for pass-through configuration.
These protocols are discussed in detail in Section 6, “TR3271 Subdevice Protocols.”
TR3271-Specific
Operations
This section discusses TR3271-specific operations and points out any TR3271-specific
variations that you should be aware of.