U.S. patent application number 11/601611 was filed with the patent office on 2007-06-07 for integrated fieldbus data server architecture.
Invention is credited to David A. Glanzer, Donald B. Goff, Lee A. Neitzel.
Application Number | 20070129820 11/601611 |
Document ID | / |
Family ID | 27567686 |
Filed Date | 2007-06-07 |
United States Patent
Application |
20070129820 |
Kind Code |
A1 |
Glanzer; David A. ; et
al. |
June 7, 2007 |
Integrated fieldbus data server architecture
Abstract
A new and improved control system architecture with a single
server interface for application software that eliminates manual
intervention by providing online, immediate access to information
needed for plant/enterprise optimization, operation, configuration,
maintenance and diagnostic application software. The control system
architecture provides a method of dynamically creating a server
directory to enable automatic access in an integrated control
system. The method includes accessing a live list of fieldbus
devices, building/updating a browse tree structure, the browse tree
structure defining a branch and leaf node organization and naming
for and data from the fieldbus devices, copying AP directories and
FF objects from active fieldbus devices into a FF directory and
mapping the FF Directory into the server directory.
Inventors: |
Glanzer; David A.;
(Georgetown, TX) ; Neitzel; Lee A.; (Austin,
TX) ; Goff; Donald B.; (Austin, TX) |
Correspondence
Address: |
DORSEY & WHITNEY LLP;INTELLECTUAL PROPERTY DEPARTMENT
SUITE 3400
1420 FIFTH AVENUE
SEATTLE
WA
98101
US
|
Family ID: |
27567686 |
Appl. No.: |
11/601611 |
Filed: |
November 16, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10226282 |
Aug 23, 2002 |
7146230 |
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11601611 |
Nov 16, 2006 |
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10160094 |
Jun 4, 2002 |
6594530 |
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10226282 |
Aug 23, 2002 |
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08916178 |
Aug 21, 1997 |
6424872 |
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10160094 |
Jun 4, 2002 |
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09598697 |
Jun 21, 2000 |
6826590 |
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10226282 |
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60024346 |
Aug 23, 1996 |
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60139814 |
Jun 21, 1999 |
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60314093 |
Aug 23, 2001 |
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60315067 |
Aug 28, 2001 |
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Current U.S.
Class: |
700/20 |
Current CPC
Class: |
Y10S 707/99945 20130101;
G05B 2219/32129 20130101; H04L 12/4616 20130101; G05B 2219/31328
20130101; G05B 2219/33152 20130101; G05B 15/02 20130101; G05B
19/4185 20130101; G05B 2219/31169 20130101; G05B 2219/31135
20130101; Y02P 90/02 20151101; H04L 12/462 20130101; G05B
2219/31118 20130101; G05B 2219/33148 20130101; G05B 2219/34263
20130101; G05B 19/41845 20130101 |
Class at
Publication: |
700/020 |
International
Class: |
G05B 11/01 20060101
G05B011/01 |
Claims
1. A method of dynamically creating a server directory to enable
automatic access in an integrated control system, comprising the
steps of: (a) accessing a live list of fieldbus devices, wherein
the live list represents active fieldbus devices in the integrated
control system; (b) building/updating a browse tree structure,
wherein the browse tree structure defines a branch and leaf node
organization, naming for the fieldbus devices and data from the
fieldbus devices; (c) copying Application Process ("AP")
directories and Foundation Fieldbus ("FF") objects from active
fieldbus devices into a FF directory so that the FF directory has
object semantics corresponding to the active fieldbus devices; and
(d) mapping the FF Directory into the server directory, wherein the
object semantics in the FF directory are mapped into the server
directory in a standardized format that is automatically accessible
by client application software running on a server.
2-20. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part (CIP) application
of U.S. patent application Ser. No. 10/160,094, entitled "A
Block-Oriented Control System" and filed Jun. 4, 2002, which is a
continuation of U.S. Pat. No. 6,424,892 (hereinafter the "'892
patent"), also entitled "A Block-Oriented Control System" and filed
Aug. 21, 1997, which claims the priority of U.S. Provisional
Application No. 60/024,346, filed Aug. 23, 1996. This application
is also a CIP of U.S. patent application Ser. No. 09/598,697
(hereinafter the "'697 application"), entitled "Block-Oriented
Control System On High Speed Ethernet" and filed Jun. 21, 2000,
which claims the priority of U.S. Provisional Application No.
60/139,814, filed Jun. 21, 1998. This application also claims
priority of U.S. Provisional Application No. 60/314,093, filed Aug.
23, 2001, and U.S. Provisional Application No. 60/315,067 filed
Aug. 28, 2001. All of the above-mentioned applications and patent
are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to automatic control system
architecture. More particularly, the present invention relates to
how plant and enterprise application software accesses control
system data including fieldbus data, needed for plant and
enterprise management, operation, configuration, maintenance, and
diagnostic functions of the control system.
BACKGROUND
[0003] Automatic control systems are critical to all sectors of
industry such as process control, discrete control, batch control
(process and discrete combined), machine tool control, motion
control, and robotics. One of the strongest needs in modern control
systems is development and use of "open" and "interoperable"
systems. Open, interoperable systems allow control devices made by
different manufacturers to communicate and work together in the
same system without the need for custom programming.
[0004] The movement toward open, interoperable control systems is
driven by plant and enterprise management, application software
suppliers, control device manufacturers, and end users. Plant and
enterprise management want open, interoperable control systems
because they need access to all of the control system information
in order to provide the analysis needed to optimize the operation
of the plant and enterprise. Client Application Software suppliers
want open, interoperable control systems so that their software can
access the control system data using standard computer platforms
running standard operating systems, and interconnected by standard
communication systems. Control device manufacturers want open,
interoperable control systems because such systems allow them to
sell their products to more end users while reducing development
costs. End users want open, interoperable control systems so that
they can select the best application software and control devices
for their system regardless of the manufacturer.
[0005] In order for control systems to be truly open and
interoperable, communications systems between devices, the user
layer (above the communication system layers) in the devices, and
the computer/application software integration architecture must be
specified and made open. "Fieldbus" is the common term used to
describe these types of automatic control systems.
[0006] One of the truly open and interoperable fieldbus control
systems is the FOUNDATION.TM. fieldbus ("FF") system provided by
the Fieldbus Foundation (Austin, Tex.). The FF user layer and a
lower speed 31.25 kilobits/second fieldbus (H1) is described in the
above-mentioned '892 patent. A High Speed Ethernet (HSE) fieldbus,
running at 100 megabit/second or higher speeds, is described in the
above-mentioned '697 application. The '892 patent and the '697
application are assigned to the assignee of the present
application.
[0007] H1 provides the open and interoperable solution for field
level control capability and integration, and HSE provides the open
and interoperable solution for distributed control on a very high
performance communication system typically called a fieldbus
control "backbone" network. The HSE control backbone aggregates
information from lower speed control devices, e.g., the H1 devices
and other control devices, which is used in supervisory and
advanced control applications. The HSE control backbone aggregates
data from high-speed control devices, e.g., HSE devices and other
subsystems, and provides access/change of H1 and HSE control
information by control system computers.
[0008] The plant/enterprise application software operates at the
"client" and "server" levels in the control system hierarchy. An
open and interoperable integrated fieldbus data server architecture
(meaning client and server) is needed that will provide a framework
and common specification for the "semantics" (how the application
software understands the control system data) of fieldbus data,
whether it is H1 or HSE data, or other control data. Prior to the
present invention, client application software on the
plant/enterprise computers had to be manually customize and adapt
data received from each server that provided access to fieldbus or
other control device data because each server identified and
represented the same semantic information differently. A
requirement for modern servers is to eliminate the need to manually
customize or adapt client application software; the present
application addresses this requirement.
[0009] Existing server specifications provide for automatic
adaptation of very limited subsets of runtime data because this
data can be understood through syntax only, e.g. message structure.
For example, the OLE for Process Control (OPC) Specification from
the OPC Foundation (Boca Raton, Fla.) provides for the limited
adaptation through standardization of the basic access mechanism
and syntax for runtime data, e.g. simple process variables (PV) and
setpoints (SP). The OPC Specifications are general enough to allow
extra information, called "properties" to define "class" attributes
of the runtime data. Class attributes include "Device Description"
(DD) information for the runtime data, e.g. help strings,
engineering units, and parameter labels. Some DD information is
complex, for example containing conditionals, menus, and methods
(which are C programs). Additional class attributes are provided by
"Capability Files" (CF) that describe the range of capability of
the fieldbus device or other control device, e.g. maximum number of
parameters, initial values of parameters, and maximum number of
communication sessions. However, although OPC allow servers to
define class attributes, there is no standardized definition for
class attributes, thus limiting interoperability with, and
automatic adaptation by, client application software
[0010] Further, even if class attributes could be standardized for
server data, the client application software also needs to know
which "instance" of the runtime data is being described by the
class attributes. That is, the class attributes can tell the client
application software what type of runtime data is being accessed,
but they cannot identify the specific data that is being accessed.
Instance information can be provided by accessing application
directories (which locate the runtime data) in the fieldbus
devices, but like class attributes, there is no standardized
definition of the application directory information making
interoperability and automatic adaptation of the client application
software impossible.
[0011] Advanced Human/Machine Interface ("HMI"), trending, asset
management, configuration, maintenance, diagnostic and
plant/enterprise management application software must have access
to runtime data and the class attributes and application directory
semantic information that allows the software to automatically
identify, interpret, and process the runtime data without manual
intervention. Finally, to be efficient, the client application
software must be able to access the runtime data and the semantic
information through a single interface.
[0012] The OPC Specification is unable to automatically and
efficiently support these advanced applications because there is no
open and interoperable framework or specification for providing the
above described semantic information to the client software
applications through the same interface that is currently used to
access runtime data.
[0013] What is needed is a framework and a common specification for
an integrated fieldbus data server architecture that can provide
semantics of runtime data, both simple and complex, to the client
application software.
[0014] What is needed is a framework and a common specification for
an integrated fieldbus data server architecture that migrates
support for existing plant/enterprise client application software,
e.g., HMI and other OPC software applications, while standardizing
and integrating the semantics needed for automatic identification,
interpretation, and processing of runtime data by advanced client
application software, e.g., plant/enterprise management,
configuration, maintenance, and diagnostics application
software.
[0015] What is needed is an integrated fieldbus data server
architecture that complements H1, HSE and other fieldbus
architectures so the plant/enterprise application software can
automatically interpret the runtime data using corresponding
semantic information.
[0016] What is needed is an integrated fieldbus data server
architecture provides a single interface for access of the runtime
data and corresponding semantic information by the plant/enterprise
application software.
SUMMARY
[0017] Embodiments of the present invention overcome the
shortcomings described above and otherwise. Embodiments of the
present invention satisfy the above-described needs. Embodiments of
the present invention provide a new and improved control system
architecture with a single server interface for Client Application
Software that eliminates manual intervention by providing online,
immediate electronic access to the runtime data and semantic
information by advanced plant/enterprise management, operation,
configuration, maintenance and diagnostic application software.
[0018] The embodiments of the present invention are collectively
referred to herein as the "Integrated Fieldbus Data Server
Architecture" (IFDSA). IFDSA provides the framework and
specification for mapping the semantic information of runtime data
such as H1 and HSE fieldbus device data described in the '892
patent and '697 application, respectively, and further defines a
single interface for client application software. The IFDSA
framework enables automatic adaptation to FF and other control
device types.
[0019] The elimination of manual intervention for setup of advanced
application packages is achieved by providing a method and
apparatus for accessing the runtime "live list" of active FF
devices and building/updating a Standardized Browse Tree Structure
formatted to be compatible OPC Specifications available from the
OPC Foundation and mapping FF Directory information (which provides
the semantic information for all FF fieldbus and other control
device runtime data) into a new Server Directory. The Server
Directory contains the same semantic information as the FF
Directory, but is formatted to be compatible OPC Specifications
available from the OPC Foundation. The OPC-compatible browse tree
and semantic information is then provided to the client application
software transparently by the servers.
[0020] The IFSDA achieves a single interface because the Client
Application Software at the client no longer has to use separate
interfaces to access semantic information and runtime data. Since
the mapping of FF semantic and runtime data to OPC Specifications
is above the communication layers, this solution remains valid as
implementations evolve to newer technologies, e.g., web
services.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Features and advantages of the present invention will become
apparent to those skilled in the art from the following description
with reference to the drawings, in which like numerals refer to
like items and:
[0022] FIG. 1 is a block diagram showing an exemplary embodiment of
an integrated open and interoperable control system in accordance
with the principles of the present invention;
[0023] FIG. 2 is a block diagram showing an exemplary embodiment of
an integrated fieldbus data server architecture with FF Directory
Mapping in accordance with the principles of the present
invention;
[0024] FIG. 3A is a flowchart illustrating an exemplary method of
creating a Server Directory to enable automatic access in an
exemplary embodiment of an integrated fieldbus data server
architecture in accordance with the principles of the present
invention;
[0025] FIG. 3B is a diagram illustrating an exemplary Standardized
Browse Tree Structure in the Server Directory and graphically
illustrating a step of building/updating the Standardized Browse
Tree Structure with exemplary Live List and Device Directories,
from the method of creating a Server Directory to enable automatic
access;
[0026] FIG. 4 is a diagram illustrating an exemplary device in a FF
Directory and exemplary OPC Items, mapped from the device, in the
Server Directory, and graphically illustrating alternative steps of
mapping the device into the OPC Item in the Server Directory as
part of a step of mapping the FF directory into the Server
Directory from the method of creating a Server Directory to enable
automatic access;
[0027] FIG. 5 is a diagram illustrating an exemplary Application
Process (AP) Directory in the FF Directory and exemplary OPC Items,
mapped from the FF Directory, in the Server Directory, and
graphically illustrating alternative steps of mapping the AP
Directory into the Server Directory OPC Items as part of the step
of mapping the FF directory into the Server Directory from the
method of creating a Server Directory to enable automatic
access;
[0028] FIG. 6 is a diagram illustrating an exemplary FF Object in
the FF Directory and exemplary OPC Items, mapped from the FF
Object, in the Server Directory, and graphically illustrating
alternative steps of mapping the FF Objects into the Server
Directory OPC Items as part of the step of mapping the FF Directory
into the Server Directory from the method of creating a Server
Directory to enable automatic access; and
[0029] FIG. 7 is a diagram illustrating an exemplary method of
Client Application Software accessing mapped FF semantic
information using the Server Browse Function, and accessing runtime
data, corresponding to the semantic information, using the Server
Data Access Function, in an OPC server in an exemplary server
directory of an exemplary embodiment of an integrated fieldbus data
server architecture in accordance with the principles of the
present invention.
DETAILED DESCRIPTION
[0030] For simplicity and illustrative purposes, the present
invention is described by referring mainly to exemplary
embodiments, particularly, with a specific exemplary implementation
of a control system using H1, HSE, OPC (meaning both client and
server operations), and Client Application Software. However, one
of ordinary skill in the art would readily recognize that the same
principles are equally applicable to, and can be implemented in,
other implementations and designs using any other integrated
architecture, and that any such variation would be within such
modifications that do not depart from the true spirit and scope of
the present invention. Specifically, one of ordinary skill in the
art would readily recognize that principles applying to OPC in the
exemplary implantation are equally applicable to non-OPC
implementations.
[0031] I IFDSA Overview
[0032] Referring to FIG. 1, an example of an integrated control
system architecture 100 is shown where standard Ethernet equipment
130 is used to interconnect HSE Linking Devices 110, HSE Devices
120, and Plant/Enterprise Computers 190 to Ethernet Network 140.
The HSE Linking Devices 110 in turn connect to H1 Devices 170 using
H1 Networks 150. Client Application Software 180 runs on the
Plant/Enterprise Computers 190. Server software may run on
Plant/Enterprise Computers 190, HSE Linking Device 110 or HSE
Device 120. Client Application Software 190 may also run on HSE
Linking Device 110 or HSE Device 120. The actual hardware and
software configuration will depend on the particular application
needs. However, network topology, devices or configuration other
than the exemplary topology shown in FIG. 1 may be used, and such
variations would be within such modifications that do not depart
from the true spirit and scope of the present invention.
[0033] IFDSA components in accordance with an embodiment of the
principles of the present invention are shown in FIG. 2. IFDSA is
designed to meet the functional needs of the integrated, high
performance distributed manufacturing and process control
environments, e.g., utilizing H1, HSE, OPC and Client Application
Software. IFDSA permits distributed automation systems to be
constructed from various H1, HSE, and other control and measurement
devices, client application software and server software
manufactured by different vendors. IFDSA is described by
architecture components that have been adapted to the specifics of
H1, HSE and OPC environments.
[0034] The various protocols and standards referenced in the
following disclosure are described in detail in the manuals and
specifications listed in Appendix I herein, which are publicly
available from the Fieldbus Foundation, a not-for-profit
organization headquartered in Austin, Tex. The specifications and
manuals may be ordered by calling 512-794-8890 or online at
www.fieldbus.org. The respective current versions of each of these
manuals and specifications are hereby incorporated by reference in
their entirety. Each of the architecture components of IFDSA (shown
in FIG. 2) are described in more detail below.
[0035] II. IFDSA Components
[0036] FIG. 2 illustrates an exemplary embodiment of the IFDSA 50.
As shown, the IFDSA 50 preferably comprises OPC 160 and Fieldbus
Devices 280 (e.g., H1 Devices 170 and HSE Devices 120--See FIG. 1).
The functions and components of OPC 160 may be combined into a
single OPC 160 computer or spread among multiple OPC 160 computers.
OPC 160 preferably communicates with the Fieldbus Devices 280 via
Fieldbus Networks 290 (e.g., H1 Networks 150 and Ethernet Networks
140--see FIG. 1).
[0037] In the embodiment shown, OPC 160 preferably includes Client
Application Software 180 and an OPC Client 210. Client Application
Software 180 uses OPC Client 210 to access information in an OPC
Server 220. OPC Client 210 and OPC Server 220 can reside in a
single computer or they may be in separate computers on a
communication network (the communication network between the client
and server is not shown in FIG. 2).
[0038] The Client Application Software 180 running in OPC 160 may
include a variety of software (e.g., as separate programs or
separate modules of the same software). For example, the Client
Application Software 180 may include Human/Machine Interface
Application Software 181, Maintenance/Diagnostics Application
Software 182, Configuration Application Software 183, and Other
Plant/Enterprise Application Software 184. The preferred embodiment
defines existing client application software to be included in
Other Plant/Enterprise Application Software 184.
[0039] Referring again to the embodiment shown in FIG. 2, a second
OPC 160 computer preferably includes an OPC Server 220 and a FF
Server Module 230. The OPC Server 220 may be a virtual server, for
example, and preferably includes a Server Browse Function 270.
Communications are preferably enabled and maintained between the
OPC Server 220, specifically the Server Browse Function 270, and
the OPC Client 210. The FF Server Module 230 preferably includes a
FF directory 240, a Mapping Function 250, and Server Directory 260.
Communications are also preferably enabled and maintained between
the OPC Server 220, specifically the Server Browse Function 270,
and the FF Server Module 230, specifically the Server
Directory.
[0040] III. IFDSA Directory Mapping
[0041] With continued reference to the embodiment illustrated in
FIG. 2, the FF Server Module 230 preferably monitors a Live List
400 that represents the active fieldbus devices in Fieldbus Devices
280. In the preferred embodiment, Live List 400 is created in
accordance with the FF Specifications in Appendix I and available
from the Fieldbus Foundation. Live List 400 identifies Fieldbus
Devices 280 available to FF Server Module 230. For each device
listed in the Live List 400, there is a corresponding list of
vendor specific identifiers called Object Dictionary (OD) Indexes
(OD Indexes not shown in FIG. 2). OD Indexes have corresponding
runtime objects in the Fieldbus Devices 280. Exemplary runtime
objects in a device are described the '892 application and include
a resource block object, transducer block objects, function block
objects, trend objects, view objects, link objects, alert objects,
system time objects, function block schedule objects, and network
traffic objects.
[0042] The runtime objects are preferably defined as FF Objects by
the FF Specifications referenced in Appendix I, although a vendor
can define additional runtime objects. In either case, DD and CF
technology mentioned above and described in the '892 application
(and the FF Specifications listed in Appendix I) are preferably
used to describe the runtime objects. DD and CF files extend the
descriptions of each object in a device that is needed for a
control system to interpret the meaning of the data in the fieldbus
device, including the human interface functions, such as
calibration and diagnostics.
[0043] The DD/CF files can be written in ASCII text or any
standardized programming language, such as C, C++, or SmallTalk. In
the preferred embodiment, DD files are written in the DD Language
(DDL) and CF files are ASCII text files as described by the FF
Specification listed in Appendix I and available from the Fieldbus
Foundation.
[0044] The FF Directory 240 is preferably composed of the list of
all Fieldbus Devices 280, called the Live List, and the AP
directories contained in each FF device. The Live List may be
constructed by listening to FF network traffic, or it may be read
from Fieldbus Devices 280 that contain it. AP directories are read
by the FF Server Module 230 from the Fieldbus Devices Fieldbus
Devices 280 via the Fieldbus Networks 290, or the AP Directories
can be obtained locally by reading the CF file (The DD and CF files
are provided with every FF fieldbus device).
[0045] The OD Index is used as a key attribute in FF protocol
services to access the runtime objects. Consequently, Client
Application Software 180 can access runtime data in the Fieldbus
Devices 280 by obtaining their corresponding OD indexes from the FF
Directory 240.
[0046] OPC 160 models runtime objects as "OPC Items". OPC Items are
identified by "Item IDs" that contain vendor-specific names. OPC
Items in the OPC Server 220 are presented to the OPC Clients 210
via a Server Browse Function 270. The Server Browse Function 270
allows the OPC Server 220 to locate OPC Items in a tree structure
that is constructed per the OPC specifications. The OPC Client 210
uses the Server Browse Function 270 to locate items of
interest.
[0047] Currently, there is no standardization of branch and leaf
node organization or ID naming used in the Server Browse Function
270 and, therefore, the OPC Client 210 cannot locate OPC Items of
interest without manual interpretation of the browse tree and each
OPC Item in it. This precludes OPC Clients 210 from automatically
accessing and processing OPC Items in the OPC Server 220.
[0048] To solve this problem, the IFDSA 50 provides a standard
Server Directory 260 that is created to represent the FF Directory
240. The Server Directory contains the same object semantic
information as the FF Directory 240, but is mapped to be compatible
with OPC objects. The Standardized Browse Tree Structure 261 in the
Server Directory 260 defines the branch and leaf node organization
and naming for the Fieldbus Devices 160 so that the Server Browse
Function 270 can locate its representation of Fieldbus Devices 280
and their data through the OPC compatible semantic information in
Server Directory 260. Once located, the OPC compatible semantic
information and data values (if any) are provided to the Client
Application Software 180 transparently using via the Server Browse
Function 270 and related OPC 160 services.
[0049] The Mapping Function 250 maps the Fieldbus Devices 280 Live
List 400 and Application Process (AP) Directory information to the
Server Directory 260 with an automatically generated OPC Access
Path Name and/or a Fully Qualified Item ID, referred to below as
the OPC Item Reference. The AP Directory is written in accordance
with the manuals or specifications listed in Appendix I and
available from the Fieldbus Foundation. The OPC Access Path name
defines the server-specific path through the Server Browse Function
270 to the FF Directory 240. The OPC Fully Qualified Item ID is a
handle to the item representing a corresponding Runtime Object in
the FF Directory 240. The OPC Access Path, OPC Fully Qualified Item
ID and Server Browse Function are written in accordance with OPC
Specifications and available from the OPC Foundation.
[0050] FIG. 3A illustrates an embodiment of a method 300 of
creating a Server Directory 260 to enable automatic access. As
seen, the method 300 starts when the integrated control system
powers-up 310 and includes the steps of: Accessing the Live List
400 of Fieldbus Devices 280, step 320; Building/Updating the
Standardized Browse Tree Structure 261, step 330; Copying AP
Directories and FF Objects from active Fieldbus Devices 280 into
the FF Directory 240, step 340; Mapping the FF Directory 240 into
the Server Directory 260, step 350; determining if there is a Live
List 400 change, step 360; and, if yes, repeating steps 330-360,
and if no, repeating step 360.
[0051] The access step 320 preferably is performed using protocol
services defined in the FF Specifications in Appendix I and
available from the Fieldbus Foundation. The building/updating step
330 initially builds the Standardized Browse Tree Structure 261
with Live List 400 Device Identification information read from
Fieldbus Devices 280.
[0052] The reading of information in step 330 preferably is
performed using protocol services defined in the FF Specifications
in Appendix I and available from the Fieldbus Foundation. (Please
see FIG. 3B and its corresponding description below for a more
detailed description of the data accessed by this step.) The
copying step 340 is preferably performed by 1) reading the AP
Directories and FF Objects of Fieldbus Devices 280 corresponding to
active devices in the Live List 400 using protocol services defined
in the FF Specifications in Appendix I and available from the
Fieldbus Foundation and placing the data in a buffer, and 2)
copying the data from the buffer to the FF Directory 240. The
mapping step 350 maps the data in FF Directory 240 to the Server
Directory 260 by mapping, for each device, an AP Directory, and
each FF Object contained in the FF Directory 240 to OPC Items in
the Server Directory 260. Please see FIGS. 4-6 and their
corresponding description below for more detailed descriptions of
this step and alternative steps of mapping these to OPC Items.
[0053] With continued reference to FIG. 3A, the determining step
360 dynamically determines if there is a change in the Live List
400. Step 360 uses the same protocol as Step 320 to access Live
List 400 and then compares the new copy of the Live List just
obtained with the previous copy and determines which fieldbus
devices have been added or removed from Fieldbus Devices 280 since
the last execution of Step 360. The determining step 360,
therefore, enables the IFDSA 50 to dynamically map the FF Directory
240 to the Server Directory 260.
[0054] FIG. 3B illustrates an exemplary Server Directory 260 with
an exemplary Standardized Browse Tree Structure 261 and graphically
illustrates an embodiment of the build/update step 330. As shown,
the Standardized Browse Tree Structure 261 includes a Live List
Directory 262 entry and a Device Directory 263 entry for each
active field device in Fieldbus Devices 280 referenced explicitly
by a Live List Directory 262 entry as shown in the figure, or
implicitly referenced as a child node or property of the Live List
Directory 262 entry (not shown).
[0055] Referring to FIGS. 2 and 3B, the Server Directory 260
structure preferably matches the organization of the FF Directory
240 Structure. Each AP Directory reference in the FF Directory 240
is composed of a Starting OD Index and a number of objects. In the
preferred embodiment, the Device Identification information, e.g.,
DeviceID, Fieldbus Network Address, Physical Device Tag, and other
related data, provides semantic information that allows clients to
automatically identify Fieldbus Devices 280. It is preferably read
from Fieldbus Devices 280 using protocol services defined in the FF
Specifications in Appendix I and available from the Fieldbus
Foundation, and is preferably mapped into the Server Directory 260
using automatically generated Item ID/Path in one of two ways:
[0056] 1. Each AP Directory reference in the FF Directory 240 as
mapped to Server Directory 260 is composed of a Starting OPC Item
Reference that identifies the branch that contains the object and
the sub-objects of the object are represented as item beneath this
branch. The browses order of the items beneath the branch preserves
the OD Index ordering as defined in the FF Specifications for the
object represented in the AP Directory; or [0057] 2. Each AP
Directory entry in FF Directory 240 as mapped to Server Directory
260 can be composed of an OPC Item Reference of the corresponding
OPC Item. In this case, FF sub-objects in the Server Directory 260
and are represented by their own OPC Item Reference of the OPC Item
that corresponds to the sub-object.
[0058] As shown in FIG. 4, the mapping step 350 of the preferred
embodiment of the method 300 maps the Live List Entry 242 from the
FF Directory 240 into the Server Directory 260. Exemplary Live List
Entry 242 in the FF Directory 240 and exemplary OPC Items 262a,
262b, and 262c, correspond to the alternative mapping options
described below. For each mapping options, the OPC Item ID and Path
(not shown on figure) are automatically generated. [0059] Mapping
Option 1, mapping the Live List Entry 242 to a tree structure of
branches and leaf nodes accessed by the OPC Browse and Read
service. The Live List Entry 242 preferably includes Device
Identification information needed to identify and communicate with
the device that is located in Fieldbus Devices 280. OPC Item 262
includes the mapped Device Identification information formatted as
an OPC Item per OPC Specifications, and the OPC Item 262a includes
the device's mapped Device Directory information or a reference,
formatted as an OPC Item per OPC Specifications; and
[0060] Mapping Option 2, mapping the Live List Entry 242 to a
single structured OPC Item accessed by the OPC Value Read service.
OPC Item 262b includes Device Identification information and the
device's mapped Device Directory information or a reference to it,
formatted and mapped to an OPC Value per OPC Specifications.
Accordingly, the Device Directory or a reference to it is included
in the value of the Browse Tree item that represents the device,
and [0061] Mapping Option 3, mapping the Live List Entry 242 to a
single structured OPC Item Property accessed by the OPC Get
Property service. OPC Item 262c includes Device Identification
information and the device's mapped Device Directory information or
a reference to it, formatted and mapped to OPC Properties per OPC
Specifications.
[0062] FIG. 5 illustrates an exemplary AP Directory 244 in the FF
Directory 240 and exemplary OPC Items 264a, 264b and 264c, mapped
from the AP Directory 244, in the Server Directory 260. In a
preferred embodiment, the AP Directory 244 can be any one of three
AP Directories known as the Function Block Application Process
("FBAP") Directory, the System Management Information Base ("SMIB")
Directory, the Network Management Information Base ("NMIB")
Directory or any other AP Directory that is written in accordance
with the manuals or specifications listed in Appendix I and 15
available from the Fieldbus Foundation. As shown, the AP Directory
244 preferably includes Header, Directory Entries (e.g., Composite
Object References and, and Composite List References) as defined in
the FF Specifications in Appendix I and available from the Fieldbus
Foundation. The OPC Items 264a, 264b and 264c correspond to the
alternative mapping options described below.
[0063] As shown in FIG. 5, the mapping step 350 of the preferred
embodiment of the method 300 maps the AP Directory 244 from the FF
Directory 240 into the Server Directory 260 by three alternative
mapping options or steps that structure the OPC Item References.
For all mapping options, the OPC Item ID and Path (not shown on
figure) are automatically generated. The AP Directory mapping
options or steps are: [0064] Mapping Option 1, mapping the AP
Directory 244 to a tree structure of branches and leaf nodes
accessed by the OPC Browse and Read service. OPC Item 264a includes
AP Directory 244 Header information mapped to an OPC Item Header
Array, and AP Directory 244 Entries mapped to OPC Item References
formatted to OPC Specifications; [0065] Mapping Option 2, mapping
the AP Directory 244 to a single structured OPC Item accessed by
the OPC Value Read service. OPC Item 264b includes the AP Directory
Header and the Directory Entries formatted and mapped to an OPC
Value per OPC Specifications; and [0066] Mapping Option 3, mapping
the AP Directory 244 to a single structured OPC Item Property
accessed by the OPC Get Property service. OPC Item 262c includes AP
Directory Header and the Directory Entries formatted and mapped to
OPC Properties per OPC Specifications. The OCP Item Value is
preferably set to "null."
[0067] FIG. 6 illustrates an exemplary FF Object 246 in the FF
Directory 240 and exemplary OPC Items 266a and 266b, corresponding
to the alternative mapping options described below and mapped from
the FF Object 246, in the Server Directory 260. In a preferred
embodiment, the FF Objects 246 are any object written in accordance
with the manuals or specifications listed in Appendix I and
available from the Fieldbus Foundation. The FF Objects 246
preferably include an object value that can be runtime data, an
Object DD that optionally contains the DD for the FF object, and an
Object CF, that optionally contains the CF for the FF object. The
OPC Items 266a and 266b correspond to the alternative mapping
options described below.
[0068] As shown in FIG. 6, the mapping step 350 of the preferred
embodiment of the method 300 maps the FF Object 246 from the FF
Directory 240 into the Server Directory 260 by two alternative
mapping options or steps that structure the OPC Item References.
For both mapping options, the OPC Item ID and Path (not shown on
figure) are automatically generated. The FF Object mapping options
or steps are: [0069] Mapping Option 1, mapping the FF Object 246 to
OPC Item 266a with a tree structure of branches and leaf nodes
accessed by the OPC Browse and Read service. OPC Item 266a includes
the runtime Object Value of FF Object 246 mapped to the OPC Item
Value, and FF Object 246 DD and CF semantic information mapped to
OPC Item reference structures formatted to OPC Specifications.
Accordingly, the semantic information for each FF Object 246 is
represented by sub items. Each of their components may be
represented as their sub items in the tree; and [0070] Mapping
Option 2, mapping the FF Object 246 to single structured OPC Item
266b where the runtime Object Value of FF Object 246 is mapped to
the OPC Item Value accessed by the OPC Value Read Service, and the
DD/CF semantic information is mapped to OPC Item Properties
accessed by the OPC Get Property service.
[0071] Referring to FIG. 2 and 3A, and FIG. 4-6, it is apparent to
anyone skilled in the art that an alternate embodiment of IFDSA 50
and method 300 is to eliminate the FF Directory 240 and modify step
340 to directly map AP Directories and FF Objects from Fieldbus
Devices 280 in Server Directory 261. It also apparent to anyone
skilled in the art that the Object DD and Object CF in FF Object
240 does not need to be read from Fieldbus Devices 280 if a local
copy of the DD/CF files are available (e.g., hard disk or CD-ROM)
and that an alternate embodiment includes reading the Object DD and
Object CF from such a local copy.
[0072] IV. IFDSA Single Client Application Software Interface
[0073] Referring now to FIG. 7, a preferred embodiment of the IFDSA
50 provides a single interface for Client Application Software 180
access to Fieldbus Devices 280 runtime data and semantic
information through OPC Client 210. The location of the H1, HSE and
other control device semantic information in Server Directory is
provided through the Server Browse Function 270 in OPC Server 220.
FF Server Module 230 supports the Server Browse Function 270 in OPC
Server 220 as described in Sections I-III above. The Fieldbus
Devices 280 runtime data can be provided to Client Application
Software 180 though the same OPC Client 210 interface as the
semantic information.
[0074] OPC Client 210 can obtain the runtime value data from the
Server Data Access Function 271 in OPC Server 220. FF Server Module
230 accesses Fieldbus Devices 280 runtime value data using protocol
services defined in the FF Specifications in Appendix I and
available from the Fieldbus Foundation. The mapping of Fieldbus
Devices 280 runtime value data accessed by FF Server Module 230 to
the Server Data Access Function 271 is defined by OPC
Specifications available from the OPC Foundation.
[0075] A preferred embodiment of the new IFDSA 50 supports
migration of existing application software, which is included in
Other Plant/Enterprise Application Software 184 because existing
application software only uses Server Data Access Function 271 and
this function is unchanged by IFDSA 50. This invention includes the
migration and coexistence of existing application software with new
Client Application Software 180 in the IFDSA 50.
* * * * *
References