SPI Programming Manual (G06.24+, H06.03+, J06.03+)

Introduction to SPI
SPI Programming Manual—427506-006
1-2
SPI and EMS
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A standard message format
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A standard message protocol
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A standard unit of information: the token
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Procedures for composing and decoding messages
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Data definitions for commonly used data structures
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Rules and guidelines governing message content and protocol
SPI and EMS
The Event Management Service (EMS) is based on SPI, and EMS messages are one
of two types of SPI messages (the other being control and inquiry messages). This
manual concentrates on the control-and-inquiry role of SPI. For information about
event messages, see the EMS Manual .
Subsystem Objects
An object is a well-defined logical or physical entity such as a device, communications
line, logical subdevice, process, processor, file, or transaction. Most objects are
controlled by subsystems, and a subsystem itself can be treated as an object. SPI is
designed to allow programmatic management of subsystem objects.
Management Applications
Management applications configure, control, monitor, and report the status of
subsystem objects. The primary tasks of a management application differ from those of
other applications. Rather than using a subsystem’s basic services, a management
application monitors and controls the subsystem itself. Because such management
tasks can be complex, repetitive, or time-consuming, they lend themselves to
programmatic solutions. Hence, the value of management applications, which can be
designed to manage individual subsystem objects or entire subsystems.
Figure 1-1 on page 1-3 shows a management application communicating with a
subsystem that consists of a single process.