TR3271 Management Programming Manual

INTRODUCTION
Required Management Functions
on the other hand, are defined at system-generation time, but
can be dynamically added or deleted using Configuration Utility
Program (COUP) commands available through the Dynamic System
Configuration (DSC) facility. Refer to the Dynamic System
Configuration Manual for details.
In the TR3271 subsystem, a Tandem system communicates with an
individual physical device by means of physical communications
lines. Each communications line is controlled by an I/O process
that is referred to by its process object name. In TR3271, each
I/O process controls one line. Therefore, you can identify a
process by using the name associated with the line controlled by
the process.
A line can have as many as 253 subordinate subdevices. Once
a subdevice is added and started, an application accesses the
subdevice--with the exception of pass-through protocol (PTP)
subdevices--through file-system requests such as OPEN and per-
forms poll and select operations using READ and WRITE.
PTP subdevices are handled differently from other subdevices.
Once added and started, a TR3271 PTP subdevice must be connected
to an AM3270 PTP subdevice using the CONNECT command through
the control-and-inquiry interface or the CONTROL CONNECT command
through the Communications Management Interface (CMI). Data
transfer between AM3270 and TR3271 occurs without an intervening
application. The application on the host does not explicitly use
the OPEN, READ, and WRITE file-system requests for data transfer
because they rely on the message-system interface.
A line within an TR3271 subsystem can be identified by its
unique line object name. Each subdevice can be identified by its
subdevice object name. You must assign a unique name to each
subdevice configured on a single line. Subdevices on separate
lines can have identical names; therefore, you must use the line
name in addition to the subdevice name to reference a specific
subdevice. For details on object names, see "Object Names" in
Section 3, "Elements of SPI messages for the Subsystem."
REQUIRED MANAGEMENT FUNCTIONS
Management of a subsystem involves monitoring and controlling the
objects defined in the subsystem, and monitoring and handling
events occurring in the subsystem.
The ability to monitor the TR3271 subsystem is significant. With
the information made available to you through monitoring, you
can make decisions needed to maintain a productive computing
environment.
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