AM3270 and TR3271 Configuration and Management Manual

Overview of AM3270 and TR3271
AM3270 and TR3271 Configuration and Management Manual—529993-001
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Overview of TR3271 Communications Subsystem
Error Handling in Pass-Through Mode
A pass-through subdevice has no application process initiating requests, so PTP must
handle errors itself.
For PTP, when a request is initiates and completes without error, an error counter is
cleared. If the request generates an error report greater than 3 to the subdevice, PTP
disables the subdevice. PTP reports the disabled status to the local-system operator
console. If a subdevice is disabled, use SCF bring it up.
Overview of TR3271 Communications
Subsystem
The TR3271 communications subsystem allows a NonStop S-series server or Integrity
NonStop NS-series server to connect to an IBM host as a 3270 controller and
associated devices. For TR3271, the HP equipment emulates one or more IBM 3270
cluster controllers in a remote 3270 byte-synchronous environment. TR3271 is
commonly used as a programmatic response to screen messages destined for IMS or
CICS terminals.
With TR3271, an HP application program appears to be a terminal to the IBM host.
Specifically, the application can act as one or more individual 3270-type terminals or
printers connected to a byte-synchronous, multipoint communication line.
The program ($SYSTEM.CSSnn.C0040P00) downloads the TR3271 protocol to the
Communications Line Interface Protocol (CLIP) in the SWAN concentrator.
Three TR3271 Modes
TR3271 may be used in three ways:
•
With application programs, acting as one or more 327x terminals or 328x printers.
•
Pure pass-through. Subdevices in this mode use the pass-through-protocol (PTP)
which logically connects them with remote AM3270 subdevices.
•
Programmed pass-through. With this method, application program(s) can open
both TR3271 and AM3270 devices, and route data written into TR3271 tributary
devices to different remote AM3270 devices using PTP connections over Expand.
When used with the AM3270 PTP, TR3271 allows 3270 devices to:
•
Connect to a NonStop S-series server or Integrity NonStop NS-series server
•
Access application programs running on an IBM system connected to the NonStop
S-series server or Integrity NonStop NS-series server