SIEMENS
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Siemens ST PCS 7 · 2017 (Preliminary edition)
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Function
(continued)
Engineering System
ES Software
Standard Engineering Software
PID tuning
The integrated PID Tuner is suitable for optimization of the
CTRL_PID and CTRL_S software controllers in circuits with PID,
PI, or P control. On the basis of an experimentally determined
model of the controlled system, favorable controller parameters
for an optimum disturbance response or an optimum control re-
sponse of the controller can be determined according to the pro-
cedure of absolute value optimization. Optimization can be car-
ried out in manual or automatic mode. The typical controller
values (actual value, setpoint, manipulated variable) are re-
corded by a trend function. The transient response of the con-
trollers with the determined parameters can be checked by de-
fining jumps. The controller parameters can be saved, and
recalled as required.
Monitoring of the control quality
The ConPerMon block determines the control quality of a con-
troller block (e.g. PID controller) on the basis of the online data
of the setpoint, actual value and manipulated variable. Depend-
ing on deviation of the comparison quality, e.g. the control qual-
ity at commissioning, it can trigger a warning or an alarm. The
faceplates of all control quality monitoring of a plant or a plant
unit can be summarized in OS screens, which enables problems
to be detected early on, analyzed, and specifically corrected.
Smith Predictor
The Smith Predictor can significantly improve the control quality
of processes with long and relatively constant dead times. By
eliminating the dead time component using a process model
running parallel to the actual process, the controller can be de-
signed for a process free of dead time, and thus set more effec-
tively.
Model-based predictive multi-variable control
Model-based predictive multi-variable controllers (MPC) sepa-
rately analyze the behavior of several interdependent variables
for complex processes over a longer period. The results are
used for optimized control of these variables. They eliminate ad-
verse interactions which occur with separate control of the inter-
dependent variables. Using a mathematical model of the pro-
cess dynamics, MPCs are able to predict the future process
response over a defined period of time (prediction horizon) and
optimize a quality criterion on this basis.
The APL provides two multi-variable controllers with different
functionalities and performance:
•
MPC4x4 (ModPreCon) for up to 4 coupled manipulated
variables and controlled variables
•
MPC10x10 for up to 10 coupled manipulated variables and
controlled variables and up to 4 measurable disturbance
variables
Note
:
Model-based multi-variable controllers make high demands on
memory and processing time of the designated automation sys-
tem. For that reason, please check the resources of the desig-
nated automation system before using them.
Graphics Designer
The project data for the engineering of the operator systems are
organized with the SIMATIC Manager. All the data relevant to op-
eration and monitoring of a process tag, such as messages and
HMI variables, are generated automatically during definition of
the automation function. A powerful graphics designer is avail-
able for the generation of process displays.
DOCPRO
DOCPRO is a tool for effective generation and management of
plant documentation in accordance with defined standards.
DOCPRO permits you to structure your project data in any man-
ner, to process them in the form of standardized circuit manuals,
and to print them in a uniform layout. You can incorporate your
own cover sheets, layouts, graphics, logos or title block data. It
is easy to control printing, i.e. you can specifically output individ-
ual parts of the project or all project data on the printer.
© Siemens AG 2017