SATO Masahito1 OKADA Satoshi1
We have developed the engineering functions for the CENTUM CS 1000, a distributed control system for medium and small-scale plants. The aim of this development is to supply engineering programs that will enable every engineer to achieve the full performance capability of their CENTUM CS 1000 without special training. The engineering functions run as Windows-based applications on personal computers with the Windows NT2 operating system. Portability of data has been prioritized to the extent that engineering data can be exchanged between the engineering functions and popular Windows-based spreadsheets or text editor applications in either a comma-delimited text or text file format.
To simplify system engineering, default settings have been prepared as far as possible. The user should use these default settings and modify them as necessary by selecting items from the dedicated menus. Engineering work has also been simplified by the categorization of engineering windows into two levels so that a system can be configured with minimal settings initially and with detailed settings later on as necessary.
In terms of the debugging and inspection phases, the virtual test function is included as one of the engineering functions in order to shorten the cycle time between debugging, correction, and verification. The virtual test function enables the engineer to debug field control station (FCS) databases at the same time from the same personal computer by inputting data values and modifying settings using the virtual FCSs (in that personal computer). .
As controlled objects have become more complex, plant operation schemes more concentrated, and plant operators fewer in number, the degree of engineering for a distributed control system (DCS) has both multiplied and diversified. Despite this, systems are required to be configured in a shorter time while engineering results are required to be of higher quality. Furthermore, in most medium and small-scale plants, the engineering of a DCS is generally performed by inexperienced engineers or those not specialized in DCSs. That is, engineers in such plants are rarely experienced in DCS engineering.
To overcome these hurdles, the following features have been incorporated into the engineering functions:
|Figure 1 Configuration of Engineering Functions|
This report explains each of these features in more detail. Refer to Figure 1 for the configuration of the engineering functions.
Figure 2 System View and Builders
|Figure 3 Basic Settings and Detailed Settings|
The system generation functions are composed of the System View window that manages and displays all of the engineering databases, and various builders that are used to modify the default settings in the control, operation, and monitoring functions. (See also Figure 2.)
1. System View
The System View window is the main window for the engineering functions and is used to:
As shown in Figure 2, the System View window is composed of three panes. The upper left pane displays the hierarchy of the folders containing engineering data. The contents of the folder selected here are displayed in the right pane. The bottom pane displays messages. If the settings in a particular file need to be modified, that file's builder can be retrieved by double-clicking on the name or icon of that file.
|Figure 4 Database Generation using Builder|
Builders are programs used to modify the settings in the control, operation, and monitoring functions. They are run from the System View window. The builder windows look and feel the same as those of common Windows NT-based applications so users of Windows should not have any problems using them.
Engineering data can be created using familiar Windows-based applications and imported into the corresponding builder. Conversely, builder-created files can be exported and opened in Windows-based applications for complex editing. In order to import and export data, the created data must be saved in a compatible file format: either the comma-delimited file format common to spreadsheet applications such as Microsoft Excel, or the text file format common to word processing and text editor applications such as Microsoft Word. Figure 5 shows an example of data exchange between a builder file and an Excel file.
Figure 5 Data Exchange with Microsoft Excel
|Figure 6 Debugging a Graphic Window|
There are two kinds of debugging functions: one for debugging the control functions and the other for debugging graphic windows. The former is referred to as a test function as it allows the engineer to debug control functions using either actual FCS hardware (a target test) or one of the virtual FCSs within a personal computer (a virtual test). The details of the test function will be described in another report.
The debugging functions for graphic windows allow graphic window actions, such as modifications according to specific process conditions, to be tested even when the tags whose data are assigned in the graphic window have not yet been created in the system. When the debugging functions are run, a graphic window and the debugging dialog box appear. By specifying a tag name, the data item and data value in the dialog box, the graphic window can be debugged. (See also Figure 6.)
The capability for multiple engineers to generate and debug graphic windows independently is of great benefit considering the system requires engineering of a large number of graphic windows.
The system also supports:
The use of personal computers for the engineering platform of the CENTUM CS 1000 system, offers the following advantages: a dedicated computer is no longer necessary, popular Windows-based applications can be used, and the most up-to-date hardware and software can be employed to keep up with technological advancements. From now on, we intend to exploit these merits to improve the engineering functions and develop more sophisticated applications.
Since it was released in 1993, CENTUM CS is widely applied in the plants of oil refinery, petrochemical, chemistry, iron and steel, non-ferrous metal, metal, cement, paper pulp, food and pharmaceutical industries, and power, gas and water supply as well as many other public utilities.