AM3270 Management Programming Manual

INTRODUCTION
Required Management Functions
Utility Program (COUP) commands available through the Dynamic
System Configuration (DSC) facility. Refer to the Dynamic
System Configuration Manual for details. Note that a LINE
is considered to be added or deleted because there is a one-
to-one correspondence between a process and a line in the AM3270
subsystem. In fact, you are adding or deleting a process.
In the AM3270 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 identified by its process object name. In AM3270, 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 255 subordinate
subdevices; however, two of these subdevices are reserved: #ZSPI
and #DEBUG.
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, an AM3270 subdevice must be connected to a
TR3271 subdevice using the CONNECT command through the control-
and-inquiry interface or the CONTROL CONNECT command through
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.
A line within an AM3270 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 identify 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 AM3270 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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