Page 44 - DCAP507_SYSTEM_SOFTWARE

System Software

Notes The framework expands previous conversation of Idioms, Super Variables, State Based Logic,
Theme Statements, etc.
The consequential Control Language varies inherently from conventional computer languages,
integrating unique accessibility concepts, including:
 Expression of real-time sequential, parallel, and continuous computation, not just calculate
time sequencing.
 Structured, about the process and control organization.
 Leveled to reflect levels of human activity.

 Producing an integrated data base, for plant operation, monitoring, control, and historical
recording of operating parameters and production states.
 Formatted, in semigraphic form, for readability.

 Complex hundred parameter Block control data structures substituted by one line
statements; the Idioms and Super Variables.
The previous references address component language concepts. The discussion will swap between
batch and continuous concerns, and between batch oriented control applied to continuous
examples and vice versa.
This aim notwithstanding, batch and continuous perspectives vary fundamentally, requiring a
rethought synthesis, an integrated viewpoint permitting each practice to advantage from the
imminent of the other. On a theoretical plane the two viewpoints can be summed up as below:

 Continuous control depends on the continuous assessment of all pertinent aspects of the
current process state, to recalculate the control actions which regulate that state for best
process performance.
 Batch control depends on an unspecified desired production course in process variable
space, on the monitoring of events which recognize the progression to later specifies or
stages of that trajectory, and on the exercise of controls and control actions to preserve or
move the process along that trajectory.

In some respects, the Batch viewpoint is simpler, defining the trajectory clearly, not relying on
its implied derivation from interacting state calculations. The application of a fully incessant
computation to the classic Batch process would be unfeasibly complex. Alternatively, the lodging
of elaborate constraint or recovery controls in a batch program can make a maze of side paths in
the logic. The similar constraint controls can expand automatically as a result of a suitable
continuous design.
Frequently application goals can be carried from either viewpoint, with interesting comparative
benefits.
One reference comprises an example in which the utilization of conventional continuous feed
forward methods allows a continuous control system to take the position of three batch phases.

2.4.1 The Role of Graphics

The Language design takes a fundamental position comparative to the typical graphic panaceas.
Graphics should improve easiness of use in more basic manners than familiarity. Actually, most
control graphic diagrams were intended with a different goal than the specification of an
integrated control application:

 Successful graphic figures abstract and abridge specialized areas of computation, and
simple designs, not common computations. On the negative side, the effect in process

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