AM3270 and TR3271 Configuration and Management Manual

AM3270 and TR3271 Configuration and Management Manual—529993-001
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Overview of AM3270 and TR3271
The AM3270 Access Method supports communications with IBM 3270 terminals that
are connected to one or more byte-synchronous 3x74-type cluster controllers.
The TR3271 Tributary Access Method supports communications with IBM mainframes
where the NonStop S-series server or Integrity NonStop NS-series server appears to
be one or more 3270-type terminals connected to one or more byte-synchronous
3x74-type cluster controllers.
Under either access method, one data-communications process (line handler) controls
a single byte-synchronous line.
Overview of AM3270 Communications
Subsystem
The AM3270 communications subsystem allows HP application programs to access
individual 3270-compatible devices connected to a NonStop S-series server or an
Integrity NonStop NS-series server through a nonswitched, byte-synchronous,
multipoint communications line. The multipoint line can consist of multiple IBM 3270-
family cluster controllers, each controller configured with 3270-family terminals and
printers.
With AM3270, application programs can issue file-system requests to a terminal or
printer on an AM3270 line without concern for low-level, communications-related
requirements such as control unit and device address, record size, and message
blocking.
These are the general characteristics of the AM3270 communication subsystem:
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Supports general polling capabilities
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Adds communication-related information to outbound messages
•
Strips communication-related information from inbound messages
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Permits standard line-at-a-time access to printers on a multipoint line
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Allows interactive access from HP program subsystems within the limitations of
3270 terminals
•
Allows remote IBM hosts to access IBM 3270 terminals and printers connected by
multipoint line to an HP host. The remote IBM hosts use TR3271 to communicate
with AM3270 through the Expand network.