Working with
assemblies
Open the database where the new
assembly is to be created then do one of the following:
·
Click the New button on the main
toolbar
·
Select File > New (or press
Ctrl+N)
The Create new item window pops
up (see figure 7). Select assembly and click the green
check. A new assembly schematic like the one shown below
opens.
Figure 12
Enter a name and comments as desired.
Note: CSI was designed to handle
assemblies as documents (see earlier note on this),
therefore, users must click the save button for the changes
to be written to the database.
The embossed
rectangle is the hydraulic schematic area where components
and subassemblies may be entered to define a hydraulic
circuit. The button labeled Chart opens the charting
application for the current assembly.
The blank
area immediately to the left of the chart button is used for
special components that are required if an assembly is to be
analyzed by the computation engine. (See
Analyzing assemblies)
To open an existing assembly, first
open the assembly listing by pressing the Assemblies button
on the main database interface. The assembly-listing window
is shown below:
Figure 13
The assemblies’ list may be filtered by
creation date or last modification date. Simply
double-click the assembly row to open the assembly.
To add a new component to an assembly,
drag and drop the desired component icon from the component
palette onto the hydraulic schematic area of the assembly.
CSI creates a new blank component and opens the appropriate
dialog box
Component
definitions can be added to an assembly using one of the two
methods described below:
·
Find (see
finding components) and select the component definitions
you want to include in the assembly then select the Copy
option under the Edit menu or press Ctrl+C.
Open the target assembly window (see
opening assemblies). Click on the gray area of the
hydraulic schematic to reset the current selection if
required then select Paste under the Edit menu or press
Ctrl+V. The selected components will be added to the
assembly.
·
Open the target assembly window. Find and
select the component definitions you want to include in the
assembly. Notice the small black dot that appears to the top
right of the leftmost-topmost selected cell. Manage both the
assembly window and the component list window such that both
the hydraulic schematic area and the aforementioned dot are
visible on the screen. Place the mouse pointer directly on
top of this black dot. The mouse will change shape as
depicted on the figure below:
Figure 14
Click and
drag the black dot (this is called the drag-drop handle)
from the component list window onto the hydraulic are of the
assembly window. While dragging, the mouse will change to
according to the following rules:
·
If only one component is being dragged, it
will show the type of component
·
If more than one component is being dragged,
it will show the “sub-assembly” icon.
On systems
with limited screen size where placing two screens side by
side is difficult it becomes useful to start the drag-n-drop
operation with the component list maximized. Having started
the drag-n-drop operation, repeatedly press Alt+Tab
until the desired assembly activates. The dragged selection
can now be dropped onto the hydraulic schematic area of the
assembly window.
Note: CSI
uses three special types of components (fluid, document, and
timing) in the assemblies that are to be analyzed (see
running the analysis). Although these components are
displayed by CSI in the gray area between the Name field and
the Chart button, they too must be dropped onto the
hydraulic schematic area of an assembly.
Components
may also be added from within the assembly. This is a useful
feature if a component exists somewhere in the active
assembly and must be used somewhere else within the same
assembly. Instead of drag-n-dropping it or copy-n-pasting it
from the component listing and re-entering project
properties, the steps described below can be followed.
·
Open the assembly where the component is to be
duplicated
·
Select the component or components that are to
be duplicated (see
selecting components/ assemblies/ logical links)
·
While holding both the control and shift keys
down (Ctrl+Shft) click and drag the selected
component(s) onto the gray area of the hydraulic schematic.
The
following window appears:
Figure 15
Select
whether you want to create copies or instances of the
selected components (see next section)
An
alternative method is:
·
Open the assembly where the component is to be
duplicated
·
Select the component or components that are to
be duplicated.
·
Select the Copy option under the
Edit menu
·
Click anywhere on the gray area of the
hydraulic schematic to reset the selection
·
Select the Paste option under the
Edit menu
The window
shown above appears. Select whether you want to create
copies or instances of the selected components.
The next
section provides a detailed explanation of the differences
between copies and instances.
In order to
describe the difference between creating copies and creating
instances, the definition of an instance must be
understood.
An instance
is the collection of intrinsic properties of a component
definition plus the collection of project related properties
of a component, if any. Any time a component is added to an
assembly from the components' palette or the components
listing, an instance of that component is being created and
project properties are associated with it. If the same
component definition is added from the components’ listing,
an additional instance of the same component is created, but
both instances reference the same component definition. If
an intrinsic property of the component definition is
modified, the property will be modified in every instance in
every assembly within the same database.
For example,
a tubing component definition is created with an outer
diameter of 0.375 in and wall thickness of 0.049 in. The
component is saved and instances of it are inserted in
assemblies A, B and C with the following lines lengths
assigned: 5 mi., 7 mi. and 4.5 mi. The tubing component
definition is then opened from the components listing and
its wall thickness is changed to 0.05 in. and saved. The
next time assembly A, B, or C is opened, the tubing
component will reflect the new wall thickness of 0.05 in.
The change of the wall thickness in the component list
caused a change in all instances of the component.
In the
picture below, the inner rectangles represent a tubing
component definition (not all properties are shown) that has
been inserted in one or more assemblies to create instances
of said component.
Figure 16
If a
duplicate component is created however (see
duplicating components), a completely new component
definition (detached from the original definition) will be
created in the component list. Changing, an intrinsic
property in one component will not change the properties in
the other because they are separate components. In the
picture below, the inner rectangle on the left represents a
component definition that has been duplicated to create the
component definition represented by the inner rectangle on
the right. Changing intrinsic properties in the first
component will not change intrinsic properties on the second
component.
When a
component definition is duplicated, a copy of
the component is being created.
CSI
detachment of intrinsic properties (directly associated with
the component definition) from project properties
(associated with an instance of a component definition)
allows for an effective way to keep component definitions up
to date.
The Control
Simulator GUI provides a way to quickly modify assembly
configurations by dragging and dropping (or copying and
pasting) components onto existing components. This feature
is most useful when a single component or subassembly is to
be replaced with another component or subassembly, but the
user wants to preserve some properties. For example,
consider a case where several hydraulic hoses are to be
evaluated for a certain application. The user can create an
assembly with all the logical links in place (for an
explanation of logical links and how to set them up see
Building the hydraulic circuit) and enter all the
appropriate properties for all the hydraulic components,
including the first hose being analyzed. The user can them
duplicate the assembly (for an explanation of assembly
duplication see
Duplicating assemblies) instead of creating the second
analysis case from scratch. Then rather than removing the
original hose component, inserting the new one and
reconnecting with logical links, the user can simply
drag-n-drop the next hose component from the components
listing onto the old hose component in the duplicate
assembly. The hose component will inherit all the project
properties (such as length) of the original hose component,
but the instance will reference the newly dropped hose
component. The process is depicted below:
Figure 17
The hose
component H4 would replace the component referred to by H1b,
effectively creating instance H4b, but the project
properties (such as the length of the hose) of instance H1b
would be inherited by instance H4b (for an explanation of
instances see
Creating instances vs. copies)
Note: To
replace a component using the copy-n-paste procedure, first
select the component that will replace the target component,
then choose Copy under the Edit menu (or press
Ctrl+C), then open the assembly where the
target component is and select the component to replace. Now
select Paste under the Edit menu.
In order to manipulate components
within assemblies, the user must first make selections as
appropriate. This section describes how components,
sub-assemblies and logical links are selected in CSI.
Because this section applies to components, sub-assemblies
and logical links within an assembly, they all will be
referred to as objects. Selections may contain
one or more objects.
Click an object to select it
Click an object while depressing the
Ctrl key to add it to the current selection
Click an object while depressing the
Alt key to remove from the current selection
CSI shows selected components and
subassemblies with embossed icons. Logical links turn white
when selected. The picture below shows a selected valve
operator component.
Figure 18
The figure below shows a selected
logical link. (For more information on logical links, see
Building the hydraulic circuit)
Figure 19
Users can create selections in CSI by
dragging a selection rectangle (selection rectangles do not
apply to logical links). Simply click and drag with the left
mouse button anywhere on the hydraulic schematic to begin a
selection rectangle. Any component fully enclosed by the
selection rectangle will be selected or deselected as
explained below:
·
Click and drag resets the current selection
and creates a new one. CSI displays the selection rectangle
in black.
·
Click and drag while depressing the Ctrl
key adds the enclosed components to the current selection.
CSI displays the selection rectangle in blue.
·
Click and drag while depressing the Alt
key removes the enclosed components from the current
selection. CSI displays the selection rectangle in red.
In the image below, CSI will reset the
current selection (the valve operator) and select the three
components enclosed by the selection rectangle. It will
select the valve operator and both restrictions at either
side of the valve operator, but not the tubing component
because the selection rectangle does not fully enclose it.
Figure 20
To edit properties of any component
within an assembly, simply double click the component icon
and enter properties in the resulting dialog box. Some
components have project dependent properties, that is,
properties that are not intrinsic to the component but
potentially change from project to project such as the
length of a hose of the precharge of an accumulator. In
these cases, CSI requires the user to enter valid values for
such properties.
CSI allows the user to specify which
analysis variables to output. An output specification is
always treated as a component project property. The image
below shows the typical arrangement of an output
specification control
Figure 21
·
Include:
The check box controls whether the variable is to be written
to the output file or not. The variable will be
written only if the box is checked.
·
Unit spec. Either type the unit to
use for output or select the unit from the pop up menu that
appears when the unit selector button (next to the units'
spec) is pressed.
·
Precision: Select the output
precision with the pull-down list immediate to the right of
the unit selector button.
The
hydraulic circuit is defined by creating logical links
between the assembly components (and sub-assemblies if
applicable. For more information see
using assemblies as building blocks). To create
the logical links follow the steps below:
·
Set CSI to "linking-mode" by holding down
(continuously) the shift key.
·
Click near the desired component’s output port
and drag while still holding the shift key down. CSI will
find the closest output port and will create a "floating
link" like the one by the mouse cursor shown below:
Figure 22
·
Continue dragging until the mouse is over the
desired inlet port of the downstream component then release
the mouse button.
·
Release the shift key
Logical
links can only be created in downstream direction, i.e.
beginning at an outlet port and ending on an inlet port.
Outlet and inlet ports are to the right and left of the icon
respectively. CSI shows the upstream portion of a logical
link in red.
The steps for copying assemblies
across databases are listed below:
·
Open the source database assembly listing
·
Open the target database assembly listing.
·
Select the assembly to be copied on the source
assembly listing
·
Place the mouse over the drag-n-drop handle
(the black dot at the top-left of the active cell), then
click and drag with the left mouse button.
·
Drop the selected assembly onto the target
assembly listing. CSI will copy the selected assembly along
with all the dependent components. If the selected assembly
included subassemblies, the entire assembly is
“flattened-out”; that is, the components in the subassembly
are brought into the same level as the top-level assembly.
CSI provides
a way to duplicate assemblies. This feature becomes very
useful in the following cases:
·
Different scenarios/cases are to be analyzed
for a single assembly.
·
The user need to create an assembly that
closely resembles an assembly that was previously defined in
CSI
To duplicate
an assembly, simply open the assembly listing, find the
assembly you want duplicate and select it with a single
click (double-clicking the assembly will cause CSI to open
it). Right-click the selected assembly and select
“duplicate” in the resulting pop up menu. The following
dialog box appears:
Figure 23
Select whether you want to create
copies or instances of the assembly components (and
sub-assembly components if present) and click the check
mark. If in doubt, create instances. For more
information on choosing component copies versus instances
see
Creating component copies vs. instances. For more
information on subassemblies see
Using component subassemblies to create complex assemblies.
Valid Assemblies
(restrictions on component connections)
The assembly editor will allow you to
construct almost any equipment arrangement you can think of.
However, the current computation engine (based on earlier
versions of The Control Simulator) is restricted to certain
predefined component arrangements. These restrictions
will eventually be removed, but, for now, you have to deal
with them.
At the highest level, allowable
arrangements must be of the form source -> line ->
discharge. Discharges may be followed by
additional line -> discharge pairs for up to eight
lines. A line is simply tubing or a hose. The
source can be thought of as the equipment located topside.
The discharge is the equipment located subsea. The
source and discharge need further clarification.
Sources and discharges must be composed
of components connected in certain predefined ways.
The following figures provide maps showing which components
may follow other components. In each figure, you must
start with a component on the left edge of the figure
(Having no line to the left of the box) and proceed to the
right along the lines until you reach a component having no
line to the right.
 
If you construct an arrangement that is
not allowed, the assembly editor will give you an error
message and a warning that the structure is not that of a
valid assembly. It also highlights the components that
are in error. In the example in Figure 25, a pressure
source is followed directly by tubing. If you look at
Figure 26, you will see that a pressure source must be
followed by a restriction, which may then be followed by
tubing.
To fix the error in Figure 25, you would delete the link
between the pressure source and the line (click on the link
to select it as in figure 19, and then press the delete
key). Then you would
add a restriction to the assembly. Finally, you
would
connect the pressure source to the restriction and then
the restriction to the line.
Figure 26 - Map of allowed component connections in the
discharge (subsea equipment). Analyzing assemblies |
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