KATAOKA Norikatsu1 TAJIMA Yasuhiro1
It is almost impossible for a single recipe management software package to cover every kind of recipe management application for differing plant scales and complexity. Our objective for the development of a recipe management package for the CENTUM CS 1000 was to design an uncomplicated package with an open interface that would be suitable for small- and medium-scale plants, the target market of the CENTUM CS 1000 distributed control system. The result of this development is PICOT, an FCS data setting/acquisition package that uses Microsoft Excel2 as the user interface. This report gives an outline of the PICOT software package.
Recipe management software refers to the computer software used to manage product names and their corresponding recipes and set the recipe data in the control system in order to control the operations of a plant in which multiple materials are blended to manufacture a number of different products. In the last few years, recipe management software has become more comprehensive and complex in order to cover all kinds of plants and all possible functions. However, not all plants need all functions. A simple function for setting groups of tag data in field control stations (FCSs) is sufficient for some plants.
PICOT, the FCS data setting/acquisition package introduced in this report, is a versatile software package. It can be used alone to provide the simple function of setting groups of tag data in FCSs and collecting the values of those data, or it can be combined with the FCS control function and easily configured to provide the complete range of recipe management functions.
All of the user interfaces of PICOT are spreadsheets of Microsoft Excel 97. This means that all of the settings needed to run PICOT are made and the collected data values viewed on familiar Excel 97 worksheets. This makes it easy for the user to define settings and modify data values. In addition, this enables the user to manage recipes from any computer installed with Excel 97, regardless of whether it is a human interface station (HIS) of the CENTUM CS 1000.
PICOT also features interfaces for the other applications of an HIS, thus allowing supervisory computers to communicate with PICOT and result data to be saved to auxiliary media.
Application to Other Purposes
The PICOT's extensive tag-data access capabilities are not restricted to recipe management but can also be used for a wide range of other purposes such as setting high- and low-limit alarms, saving group data during a test, as well as data acquisition and printing.
Using two or more HISs, a master/slave configuration can be built in order to ensure data security.
Support of Earlier Field Control Station Models
PICOT not only supports the FCSs of the CENTUM CS 1000 but also any FCS model supported by an HIS.
Table 1 Commands
Definition File Name
|Copies the specified grade definition file to the grade file.|
|Assign Product File Name||Copies the specified product definition file to the product file.|
|Download||Downloads the specified group of data to FCSs|
|Upload||Uploads the values of the specified function blocks from the FCSs and stores them to the product file.|
|Write Time Data||Writes the current time to the product file.|
|Check Flag Status||Checks the status of the specified internal switch and quits the procedure if the internal switch is not in the specified status.|
|Set Flag||Sets or resets the specified internal switch.|
|Check Cell Status||Checks the content of the specified cell in the grade file and quits the procedure if it is not in the specified status.|
|Set Production Volume||Sets the value acquired from the specified function block, in the grade file.|
|Start Process||Runs the specified process.|
|Start Macro||Runs the macro in the grade file or product file.|
|Check Host Name||Reads the character string in the specified function block, and quits the procedure if the character string does not agree with the local host name.|
|Quit Procedure||Stops the procedure.|
|Figure 1 Overview of PICOT|
Figure 1 shows an overview of PICOT's function, and Figure 2 shows how it is configured. The definition files are Excel worksheets filled with the settings made by the user. The control file is a copy of definition files. The meaning of each file is outlined below.
Data Setting Procedure
Figure 2 Software Configuration
Data Acquisition Procedure
The following gives an example of recipe management using PICOT.
|Figure 3 Operation Time Chart of Polymerization Reactors A1 and A2|
Assume that two polymerization reactors A1 and A2 are connected in series. Figure 3 shows the operation time chart of reactors A1 and A2 and the times when the %M30001 to %M30004 sequence messages are to be notified to PICOT.
Recipe Reservation Window
To achieve recipe management using PICOT, a recipe reservation window must be prepared using a graphic window of the CENTUM CS 1000. The recipe reservation window serves as the user interface for reserving recipes. In the example shown in Figure 4, up to five recipes can be reserved. To reserve a recipe, the user must set the previously defined recipe name and batch ID in this window. In this example, the user can select one of the three pre-defined brands. The batch ID is an arbitrary four-digit number. Clicking the Set button moves the recipe reserved in reservation No. 1 to the control recipe for reactor A1. As a follow-up to this action, the remaining reservations are shifted up by 1.
Figure 4 Recipe Reservation Window
Function Blocks to Be Prepared for PICOT
The following function blocks must be prepared for the recipe reservation window and PICOT:
The data setting definitions in each grade definition file must be coded such that the data values are set in the user-defined data items of a unit instrument block in an FCS. Likewise, the data acquisition definitions for the result data must be coded such that the values of the user-defined data items of a unit instrument block are collected from an FCS.
Files to Be Prepared for PICOT
The following files must be prepared for use by PICOT:
Operations of Recipe Management Application
The following outlines the operations of the recipe management application in this example:
Before these operations can be carried out, the recipe data must be set in the grade definition files of all three products. In addition to the production control procedure, a batch report can be printed using the print function of Excel once all of the result data for reactors A1 and A2 have been collected.
This practical example shows how PICOT was used to develop application software for the recipe management of a polymerization process. The contents of this application software are as described in the above procedure. Using this example as a base for the engineering of a batch system employing PICOT, will greatly facilitate your engineering work.
PICOT is also useful in various other applications besides recipe management.
When switching the product to be produced, the high- and low-limit alarm settings of the related function blocks may need to be changed all at once. PICOT can do this if a grade definition file is prepared and a sequence message raised for each brand.
During the development of the application software, the same data may be set many times over to repeatedly test that the settings are correct. By defining those data items in a product definition file and grade definition file, the values of the necessary data items can be collected whenever desired and then set in the data items as many times as necessary.
This report gives an overview of PICOT, the new FCS data setting/acquisition package, and examples of how PICOT can be applied to recipe management and other applications. As is mentioned above, PICOT was designed to be versatile and easy- to-use. We believe that users will be able to devise many different ways of using PICOT for a broad range of purposes and that PICOT will prove extremely helpful.
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.
Our distributed control system (DCS) enables automation and control of industrial processes and enhanced business performance. Over 10,000 plants entrust Yokogawa DCS to deliver their production goals.