Title: Method for the production of an open-loop control block and said control block
Abstract: With a method for producing the control module, the control module is assembled from a number of program modules which are designed for one basic function in each case. Each program module has an interface of an interface type defined by the respective basic function. A functional connection is preferably only established between two program modules if the two program modules have mutually corresponding interfaces of the same interface type. The method permits simple, quick and in particular rule-based automatic production of the control module of a control system for controlling a plant component.
Patent Number: 6,871,104 Issued on 03/22/2005 to Lenhart, et al.
| Inventors:
|
Lenhart; Bernd (Wachenroth, DE);
Simmerer; Helmut (Mohrendorf, DE)
|
| Assignee:
|
Siemens Aktiengesellschaft (Munich, DE)
|
| Appl. No.:
|
979445 |
| Filed:
|
November 21, 2001 |
| PCT Filed:
|
May 15, 2000
|
| PCT NO:
|
PCT/DE00/01526
|
| 371 Date:
|
November 21, 2001
|
| 102(e) Date:
|
November 21, 2001
|
| PCT PUB.NO.:
|
WO00/72097 |
| PCT PUB. Date:
|
November 30, 2000 |
Foreign Application Priority Data
| May 25, 1999[DE] | 199 23 977 |
| Current U.S. Class: |
700/18; 700/19; 700/20; 700/86; 700/87; 700/88; 710/105; 713/1; 713/2; 713/100 |
| Intern'l Class: |
G05B 011//01 |
| Field of Search: |
700/17,18,19,20,83,86,87,88,89
710/105
713/1-2,100
|
References Cited [Referenced By]
U.S. Patent Documents
| 4639852 | Jan., 1987 | Motomiya | 700/9.
|
| 5058043 | Oct., 1991 | Skeirik | 700/167.
|
| 5452420 | Sep., 1995 | Engdahl et al. | 710/105.
|
| 5801942 | Sep., 1998 | Nixon et al. | 700/83.
|
| 6009268 | Dec., 1999 | Reis et al.
| |
| H1853 | Jun., 2000 | Wilkiewicz | 709/203.
|
| 6266726 | Jul., 2001 | Nixon et al. | 710/105.
|
| 6414594 | Jul., 2002 | Guerlain | 340/506.
|
| 6581847 | Jun., 2003 | Kline et al. | 236/49.
|
| Foreign Patent Documents |
| 196 15 389 | Oct., 1997 | DE.
| |
| 196 21 828 | Dec., 1997 | DE.
| |
| 0 331 551 | Sep., 1989 | EP.
| |
| 0860 758 | Aug., 1998 | EP.
| |
| WO 97/03389 | Jan., 1997 | WO.
| |
| 97/03389 | Jan., 1997 | WO.
| |
Other References
"L'Objet d'automatisme: application de concepts d'objet a la programmation
des automates", Mouna Mellah et al., APII, vol. 29, n. Jan. 1995, pp. 39
to 79.
"L'objet d'automatisme: application de concepts d'objet a la programmation
des automates", Mellah et al., APII. vol. 29-n.degree. Jan. 1995, pp. 39 a
79.
"SPS-Esperanto", Manfred Holder, Industrie-Elektrik & Elecktronik, 33,
Jahrgang 1988, Nr. 1, pp. 16-18.
"Bausteinkonzept fuR die Programmierung von Fertigungsaufgaben", Eckhard
Hohwieler et al., Carl Hanser Verlag Munchen ZWF 91, pp. 254-257 (1996).
"Visual Basic -Dad Kompendium", Peter Monadjemi, Markt & Technik Buch-und
Software-Verlang GmbH, pp. 159-163, 1997.
|
Primary Examiner: Patel; Ramesh
Attorney, Agent or Firm: Harness, Dickey & Pierce, P.L.C.
Parent Case Text
This application is the national phase under 35 U.S.C. .sctn. 371 of PCT
International Application No. PCT/DE00/01526 which has an International
filing date of May 15, 2000, which designated the United States of
America, the entire contents of which are hereby incorporated by
reference.
Claims
What is claimed is:
1. A method for generating a control module of a control system for
controlling a plant component, comprising:
assembling the control module from at least two program modules, each
designed for one respective basic function, wherein each program module
includes an interface of an interface type defined by the respective basic
function; and
assigning a first program module including a first interface to a second
program module including a second interface, wherein a functional
connection is established between the first program module and the second
program module if the first interface and the second interface are of the
same interface type.
2. The method as claimed in claim 1, wherein the basic function of at least
one of the program modules is assembled from at least two subfunctions.
3. The method as claimed in claim 2, wherein the at least one program
module includes an equal number of interfaces and subfunctions.
4. The method as claimed in claim 3, wherein at least one of the program
modules are selected from a library.
5. The method as claimed in claim 3, wherein a functionality of the control
module is specified, and wherein the control module selects the at least
two program modules on the basis of the specification of said
functionality.
6. The method as claimed in claim 3, wherein at least one program module
including one of the basic functions "operator instructions", "automatic
instructions", "protection instructions", "instruction generation",
"storage", "instruction output", "record messages", and "lamps" is
selected from the program modules.
7. The method as claimed in claim 2, wherein at least one of the program
modules are selected from a library.
8. The method as claimed in claim 2, wherein a functionality of the control
module is specified, and wherein the control module selects the at least
two program modules on the basis of the specification of said
functionality.
9. The method as claimed in claim 2, wherein at least one program module
including one of the basic functions "operator instructions", "automatic
instructions", "protection instructions", "instruction generation",
"storage", "instruction output", "record messages", and "lamps" is
selected from the program modules.
10. The method as claimed in claim 1, wherein at least one of the program
modules are selected from a library.
11. The method as claimed in claim 10, wherein at least one program module
including one of the basic functions "operator instructions", "automatic
instructions", "protection instructions", "instruction generation",
"storage", "instruction output", "record messages", and "lamps" is
selected from the program modules.
12. The method as claimed in claim 1, wherein a functionality of the
control module is specified, and wherein the control module selects the at
least two program modules on the basis of the specification of said
functionality.
13. The method as claimed in claim 5, wherein the functionality is
specified by a user input.
14. The method as claimed in claim 13, wherein the user input is subjected
to a plausibility check, and wherein a program module includes a basic
function used for the functionality of the control module, not specified
by the user, and automatically selected.
15. The method of claim 13, wherein the functionality is elicited from the
user using a query routine.
16. The method as claimed in claim 1, wherein the control module is
assembled from the program modules on the basis of rules.
17. The method of claim 16, wherein the control module is automatically
assembled.
18. The method as claimed in claim 1, wherein the internal interfaces,
active only within the control module, are standardized so that data
exchange between the program modules within the control module is not
influenced by changes to the internal program flow of a program module.
19. The method as claimed in claim 1, wherein for external data exchange
between the control module and the plant component, a device-specific
device module is selected as the program module.
20. The method of claim 19, wherein the external data exchange is over a
data bus.
21. The method as claimed in claim 1, wherein at least one program module
including one of the basic functions "operator instructions", "automatic
instructions", "protection instructions", "instruction generation",
"storage", "instruction output", "record messages", and "lamps" is
selected from the program modules.
22. The method as claimed in claim 1, wherein the at least one program
module includes an equal number of interfaces and subfunctions.
23. A control module of a control system, for controlling a plant
component, comprising:
at least two program modules, each designed for one respective basic
function, wherein each program module includes an interface of an
interface type defined by the respective basic function, wherein a first
program module including a first interface is assigned to a second program
module including a second interface, and wherein a functional connection
is established between the first program module and the second program
module if the first interface and the second interface are of the same
interface type.
24. The control module as claimed in claim 23, wherein the basic function
of at least one of the program modules is assembled from at least two
subfunctions.
25. The control module as claimed in claim 24, program module includes an
equal number of interfaces and subfunctions.
26. The control module as claimed in claim 23, wherein the at least one
program module includes an equal number of interfaces and subfunctions.
27. The control module as claimed in claim 23, program modules are selected
from a library.
28. The method control module as claimed in claim 27, wherein at least one
program module including one of the basic functions "operator
instructions", "automatic instructions", "protection instructions",
"instruction generation", "storage", "instruction output", "record
messages", and "lamps" is selected from the program modules.
Description
FIELD OF THE INVENTION
The invention generally relates to a method for producing a control module
of a control system for controlling a plant component and to a control
module produced using the method.
BACKGROUND OF THE INVENTION
In an industrial plant, for example in a power generation plant, individual
plant components are connected to one another by a control system (process
control system), in particular a digital control system. Such a plant
component may be a valve or a motor for example. An individual plant
component usually interacts here with a multiplicity of other plant
components, and its operating state is dependent on the operating states
of the other plant components. The control system is used to monitor the
operating states, and the plant is controlled automatically or manually.
To operate the plant, it is necessary to record the data of the various
plant components and establish the interrelationships between the data.
Based on this data, a control instruction is then sent by the process
control system to the respective plant component, either automatically or
in response to a manual input instruction of the operator.
For the control of a plant component, a so-called control or function
module is usually employed in the control system to record the individual
data, evaluate it and if appropriate, forward it after preprocessing.
Owing to the manifold ways in which the plant components interact and the
resulting large volume of data, the control or function modules are very
large and complex. The greater their complexity, the more difficult it
becomes to follow the internal function sequences of the individual
control module. Owing to the manifold interactions to be taken into
account, the creation of a control module is likewise highly complex, and
consequently time-consuming. Moreover there is a risk of errors arising
during the design and programming of the control module which are not
detected.
Adapting an existing control module to a specific plant also requires a
multiplicity of settings and parameter inputs. Only then can the existing
control module be integrated in the process control system of the specific
plant. Users find it difficult to grasp the complex dependencies within
the control module and its functions. As a result, modifying an existing
control module is time-consuming and requires a lot of effort. In
addition, it is very difficult to predict the effects of modifications to
the control module, that is to say to specific circuits or program flows.
Moreover, the control module is often not used optimally, so that some of
its functions remain unused. For the most part, control modules are
intentionally equipped with a large number of functions to cover as many
requirements as possible. This requires a large amount of computing power,
even if the multiplicity of functions is not necessary for a specific
plant.
Described in WO97/03389 is a method for creating a function plan in which
inputs and outputs of modules displayed on the screen are connected to one
another by a user drawing lines. A program stored in the computer then
performs a plausibility check on the connections between the modules.
The disadvantage of this is that drawing lines is prone to errors and the
subsequent plausibility check is costly.
SUMMARY OF THE INVENTION
The object of the invention is to disclose a method for producing a control
module in which the control module can be created as easily and with as
few defects as possible, and which has a structure that is readily
comprehensible to the user. A further object of the invention is to
disclose a control module produced according to the method.
According to the invention, an object is achieved by a method for producing
a control module of a control system for controlling a plant component.
Preferably, the control module is assembled from a number of program
modules designed for one basic function in each case, and of which each
program module has an interface of an interface type clearly defined by
the respective basic function. More preferably, a first program module
having a first interface is assigned to a second program module having a
second interface. A functional connection is then preferably established
between the first program module and the second program module if the
first interface and the second interface are of the same interface type.
A first aspect of the underlying idea here is the breaking down of the
complex overall functionality of the control module into individual
elementary basic functions. Preferably, a separate program module is
provided for each of these individual basic functions. The modular
structure of the function sequences in the control module renders its
overall structure very clear and readily comprehensible to a user.
A second aspect of the underlying idea here is the fact that each program
module has an interface clearly assigned to its basic function. The first
program module is preferably only connected to the second program module
if the latter's interface is designed for interfacing with the basic
function of the first program module. A specific interface which is
clearly different from all other interfaces of the other basic functions
is assigned to each basic function. This ensures that only program modules
designed for a functional interconnection can be connected to one another.
When a user is assembling the control module from the individual program
modules, this consequently precludes the possibility of errors resulting
in a malfunctioning of the control module. The control module can thus be
easily created.
The creation or production of the control module is also understood here to
include any necessary modifications, for example, as a result of
plant-specific requirements for an already existing control module. An
advantage of the method is conferred by the fact that it is possible to
make the necessary modifications simply by selecting the specific program
module requiring modification. The program module may then either be
modified or replaced by a plant-specific program module.
For better clarity, the basic function of at least one of the program
modules is preferably assembled from a number of subfunctions. For example
an "instruction generation" control module is provided in which the data
arriving from various components is recorded, processed and evaluated. The
subfunctions are expediently assigned to the different components.
It is particularly advantageous if the at least one program module has the
same number of interfaces as the number of subfunctions, with each
individual one of said interfaces being clearly defined by the
subfunction. The aforesaid "instruction generation" program module would
accordingly have a number of specific interfaces. For example, it has an
interface A' for recording the data from a device A and a further
interface B' for recording the data B from a device B. The data from
device A is preferably only transferred to the program module via the
interface of the type A' provided for the data.
The functional connection between two program modules can therefore be
compared to the joining of two jigsaw pieces: each piece of the jigsaw has
a specific geometric shape having convexities and concavities with which
only the respective matching piece can mate. It is not possible to join
two jigsaw pieces that do not fit. A program module divided into a
plurality of subfunctions is comparable to a jigsaw piece to which a
plurality of other jigsaw pieces may be simultaneously connected. The
interfaces of the program modules therefore represent the convexities and
concavities on the technical programming level.
To enable the control module to be produced as simply and quickly as
possible, the individual program modules are preferably selected from a
library. The library is, for example, a data store in which a multiplicity
of program modules having different functions are stored.
In order wherever possible to equip the control module only with the
functions required in the specific plant, the required functionality of
the control module is specified, and the program modules required are
selected on the basis of this specification.
The functionality is preferably specified by a user input, to be precise
the user is prompted to specify the functionality by using a query
routine. For example a screen-driven dialog with the user is provided for
this purpose, in the course of which the user is questioned about the
plant components provided for the plant. The user enters the
specifications for the respective plant component in a corresponding
dialog field.
The user input is preferably subjected to a plausibility check to prevent
malfunctions occurring on the assembled control module. If required by the
plausibility check, a program module which has a basic function essential
for the functionality of the control module, but which was not specified
by the user, is automatically selected.
In a particularly preferred embodiment, the control module is assembled
from the program modules on the basis of predetermined rules, in
particular automatically assembled. For example, a first rule specifies
that a program module M is automatically selected if a program module N
was selected, or else that the program module M is excluded if program
module N was selected. A second rule provides that, preferably, only
interfaces having compatible attributes are connected to one another. For
example, the type and number of inputs and outputs of an interface, as
well as the data format of the data to be exchanged between two program
modules, are compared when connecting two program modules. A third rule
provides, for example, that an input module, via which inputs are
transferred to the control module, operates with an output module via
which data is output from the control module. And a fourth rule may
include adherence to certain processing sequences of flow processes
determined by causalities.
The program modules with their function-specific interfaces are a basis for
the assembly of the control module according to fixed rules. In particular
they are highly advantageous for automatic assembly. With automatic
assembly, the user need only enter the plant-specific data. On the basis
of these inputs, the required overall functionality of the control module
is determined; the corresponding program modules are automatically
selected and assembled. The automatic production of the control module
offers considerable time savings in comparison with manual production of
the control module. Moreover, user-specific errors are precluded.
Preferably at least the internal interfaces active only within the control
module are standardized so that data exchange between the program modules
via said internal interfaces is not influenced by changes to the internal
program flow of a program module. The advantage of standardizing the
interfaces is that any necessary plant-specific adaptations to individual
program modules can be readily performed. There is no risk here that such
modifications will have an adverse effect on the functional interaction of
the individual program modules.
In addition to internal interfaces, the control module also has external
interfaces via which it is connected to external components, for example
to another control module, to the plant component, or to a data line.
For external data exchange between the control module and the plant
component, a device-specific device module is preferably selected as the
program module. In particular, the device module has a device-specific
interface; it is designed as a type of driver or communications module
which enables the control module to communicate with the plant component.
To achieve an object associated with the control module, the control module
is produced in accordance with the method described above. Similar
advantages and special embodiments that apply to the method apply somewhat
analogously to the control module.
BRIEF DESCRIPTION OF THE DRAWINGS
An exemplary embodiment of the invention is described in greater detail
below with reference to the figures, in which, schematically in each case:
FIG. 1 shows a control module assembled from individual program modules,
FIG. 2 shows a technical arrangement of devices for carrying out the method
for producing the control module, and
FIG. 3 shows a greatly simplified block diagram of a plant.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to FIG. 1, a control module 1 has a plurality of program modules
P1 to P10 which are functionally interconnected. The control module 1 is
designed to control a plant component 2, for example for the drive control
of a motor. In the exemplary embodiment, the basic functions of the
program modules P1, P2 and P3 are divided into a plurality of subfunctions
which are indicated by dashed lines in each case. Only a single basic
function is assigned in each case to the remaining program modules P4 to
P10.
The program modules P1 to P3 have a plurality of interfaces and the program
modules P4 to P10 have only one interface in each case. The designation of
the interfaces in FIG. 1 will be explained further below. The definition
of the individual interfaces is defined by the special basic function or
the subfunction of the program module. For this purpose specific
programming attributes are assigned to the interfaces, such as for example
the type and number of inputs or outputs, the data format used for
communication between the program modules P1 to P10, or a data address
assigned to the program module.
The program module P1 has for example the function "priorities and
instruction generation" as its basic function. The basic function is
divided into a plurality of subfunctions. One of these serves to process
operator instructions. Assigned to the subfunction is an interface P1A of
the program module P1, via which the latter is connected to the program
module P4 having the basic function "operator instructions". For this the
program module P4 has an interface P4A compatible with the interface P1A.
The two interfaces P4A and P1A have mutually corresponding attributes so
that they are compatible with one another.
An interface type having attributes clearly defined by the respective basic
function or subfunction is therefore assigned to each program module P1 to
P10. The interface types, which can be clearly distinguished from one
another, are denoted by letters A to N in FIG. 1, with the same letter
denoting the same interface type. Indicated here as interfaces of the same
interface type are interfaces having mutually corresponding attributes. A
type A interface P1A of the program module P1 can therefore only have a
functional connection with a corresponding type A interface P4A of another
program module, for example of the program module P4. The same applies to
the program module P5 having the basic function "automatic instructions",
by means of which instructions automatically triggered by the process
control system are generated and output. The program module P5 has an
interface P5B which is designed for the functional connection with the
corresponding interface P1B of the program module P1. Since the interface
types A and B are different, the program module P5 cannot be connected to
the interface PIA via its interface P5B. The same applies analogously to
all further program modules.
It is not necessary for a program module to be connected to each interface
PIA to P1H of the program module P1. Depending on the overall
functionality required for the control module 1, some subfunctions of the
program module P1 can remain unused. In this case some interfaces,
interfaces P1C and P1E in the exemplary embodiment, therefore remain
unassigned. They are designed for example for communicating with another
control module, and a program module designed for communication with the
further control module can be subsequently connected to them without any
problem. The interfaces P1C and P1E are therefore to be viewed as external
interfaces that have no internal effect in the control module 1.
The program module P6 has for example the basic function "protection
instructions" which is used to process instructions for protecting the
plant component. Like all other interfaces generally, the associated type
D interface also has an output and an input. The program module P2 has the
basic function "storage" and serves to store instructions before they are
output externally. Instructions are output here via the program module P7
having the basic function "instruction output". For this the two program
modules P2 and P7 are connected via the interface combination P2N-P7N. For
controlling the plant component 2, the control module 1 is connected via
the program module P7 to said plant component 2.
For this purpose, the program module P7 is designed in particular as a
device-specific device module. It therefore preprocesses the instructions
output by the program module P2 so that they can be executed by the plant
component 2. Its interface P2N can therefore be viewed as an external
interface to the specific device module. The device module P7 thus
provides for the communication between control module 1 and plant
component 2. If the plant component 2 is exchanged, the device module P7
need only be adapted to the new plant component 2, or the old device
module P7 need only be replaced by a new one. The internal processes in
the control module 1 remain unaffected by this.
The output of instructions via the device module P7 is preferably to a data
bus 4. The instructions are transferred to the plant component 2 over the
data bus 4. The data bus 4 is designed, for example, as a field bus,
through which various plant components 2 are connected to one another.
The program module P3 has the basic function "record messages". In addition
to recording messages from plant component 2, it also serves to monitor
the latter. It is connected to the program module P1 and to the program
module P2 for data exchange. In addition it has interfaces P3K, P3L and
P3M, via which it is connected to the program modules P8, P9 and P10
respectively. The program module P8 has for example the basic function
"record acknowledgements", and the program module P9 has the basic
function "record switchgear". Accordingly, the acknowledgements, for
example from the plant component 2, are processed via the program module
P8. And in program module P9 the messages from a switchgear unit 6 are
processed. The program module P10 serves for example to monitor and
control at least one pilot lamp 8 of an operating or control screen 24
(cf. FIG. 3) visible to the operator. The program module P10 has the basic
function "lamps".
The internal program flows of the individual program modules P1 to P10 are
self-contained and do not interact directly with the internal program
flows of other program modules. The individual program modules P1 to P10
can therefore be designated non-interacting. They communicate with one
another only via their standardized interfaces. Modification of the
internal program flow of a program module P1 to P10 does not affect the
interface function.
With the method for producing the control module 1, the functionality of
the control module 1 is preferably defined first. This is performed in
particular using a dialog or query routine with the user. According to
FIG. 2, there is provided for this purpose a computer unit 10 which is
connected to an input device 12, a display device 14 and a data store
forming a library 16. Stored in the computer unit 10 is a query routine,
in the course of which the user is questioned about the desired
functionality of the control module 1. For this, the user can communicate
with the computer unit 10 via the display device 14, for example via a
screen, and via the input device 12, for example via a keyboard. Displayed
on the display device 14 is a query or input screen, by means of which the
user is prompted to enter and define plant-specific features. The user
enters the features via the input device 12.
On the basis of the overall functionality of the control module 1
determined from the user's inputs, the computer unit 10 automatically
selects the necessary program modules from the library 16 and combines
them on the basis of the rules likewise stored in the computer unit 10.
The user's inputs are here subjected to a plausibility check. The computer
unit 10 is designed in such a way that it detects incorrect or inadequate
inputs and reacts accordingly, for example with an error message or a
repeated prompt. Program modules which are necessary for the desired
overall functionality of the control module 1, but which were not entered
by the user, are also automatically selected from the library 16 by the
computer unit 10.
The library 16 includes a multiplicity of individual program modules for
different requirements, so that wherever possible the necessity of
programming a program module is dispensed with when producing a special
control module 1 adapted to a specific plant component.
According to FIG. 3, a plant 18, for example a power generation plant, has
a control console 20 and a number of plant components 2A, 2B, of which
only two are illustrated. The plant components 2A, 2B and the control
console 20 are connected to a control system 22 which has the control
module 1 for controlling one of the plant components 2A, 2B. For this
purpose the control system 22 is connected to the plant components 2A, 2B
via a data bus 4. The control console 20 has an operating or control
screen 24 comprising a number of pilot lamps 8. The plant 18 can be
controlled and monitored from the control console 20.
It is preferred for the method for producing the control module 1 that the
overall functionality of the control module 1 is divided into a plurality
of basic functions and subfunctions. More preferably, each basic function
is handled by one program module P1 to P10. The program modules P1 to P10
have here in each case interfaces of different interface types A to N
which are clearly defined by the basic functions or subfunctions. The
modular structure and the clearly defined interfaces in particular enable
the automatic rule-based production of the control module 1.
The invention being thus described, it will be obvious that the same may be
varied in many ways. Such variations are not to be regarded as a departure
from the spirit and scope of the invention, and all such modifications as
would be obvious to one skilled in the art are intended to be included
within the scope of the following claims.
*
