Java Automation And Related Specification Requests

Introduction

There are currently two JSRs (Java Specification Request) at the JCP (Java Community Process) that addressed needs for automations. JSR-7 is a request for an Industrial Automation Extension API and JSR-60 is an API draft for Building Automation. The RTSJ (Real Time Specification for Java) API, that had a final release at the beginning of the year (2002), is extended under JSR-50, which is an API for Distributed Real-Time Specification. Although, data processing is a major part and very important for application development in the automation industries, Control Systems Engineering is the utmost concern for any software architectural systems design. In this article, I will briefly describe, the application of these APIs and industries involved.

Industrial Automation Extension

This is a request (JSR-7) to draft an industry standard API for the automation industries and it is based on Java and Jini. It is a distributed, real-time, industrial automation extension to the Java platform, which will be utilized in factory automation environments as well as other automation application areas. The development will lead to an Enterprise Industrial Automation and Control System that incorporates control at the factory floor level. There will be management information processing and control using Java distributed process through the internet.

This Internet based solution will be both hard real-time and soft real-time. Hard real-time are defined as systems which must satisfy the deadlines on every occasion while soft real-time describe as systems for which an occasional failure to meet a deadline does not comprise the correctness of the system. It will also have all the capabilities for complex data handling, data warehousing, and integration with legacy systems and devices.

Industrial automation is defined as the control of an industrial process (manufacturing, production, and so on) by automatic rather than manual and Control System Engineering is at the heart and core of this. Automation first became popular in the automobile industry in the 1970s. The purpose of automation is to increase productivity. Productivity is the ratio of physical output to the physical input and it is a reference to labour productivity, which is real output per hour of work.

The proposed name for this package is "java.industrial" although not finalized yet. The target platform includes desktop, server, personal, embedded, card, and a final draft is expected at the end of this year. This API is targeted for development of large scale Java Distributed Control Technology, and it is designed to be scaleable, robust, and reliable Industrial Control solutions utilizing Java technology. The industrial control and automation solutions will utilize reliable Internet infrastructure as the principle mechanism to enable distributed control technology, where Java is already the number one preferred platform for the internet.

The successful adoption of a distributed computer control scheme is often the facilities provided for the plant (physical system for automation) operator or user of the system. A clear system for the day-to-day operation of the plant must be provided. All the information relevant to the current state of its operation should be readily available and facilities to enable interaction with the plant : to change set-points, to adjust actuators (device that provides the motive power to the process such as a dc motor), to change gain parameters for PID (proportional-integral-derivative) controllers, to acknowledge alarm conditions, and so on - should be provided. This can be provided in by Java GUI, either by Java Swing or Java Abstract Windows Toolkit and this interface is called Human Machine Interface (HMI). The GUI tools and are either based on a bit map screen with hotspot to activate a programs. These HMI's are relevant to the local HMI database which in turn will communicate with underlying control structure, which needs to get synchronized in order to offer a cohesive environment. Security is utmost important, because a hacker cannot be allowed to get access to the control automation to change any settings of the plant operations, and Java provides excellent security.

Display can be developed in Java Swing: an alarm overview presenting information on the alarm status of large areas of the plant; a number of area displays presenting information on the control systems associated with each area; loop display giving extensive information on the detail of a particular control loop; show analog data either as a number, or graphically; displays to show trends and summaries of past operations (such as past set-points, alarm set-off time, PID gains, and so on). The safe operations of complex industrial automation such as a chemical plants or a nuclear power stations can be crucially affected by the way in which information is presented to the operator.

This Industrial Automation Extension API will open the door for development of SCADA (Supervisory Control And Data Acquisition ) software application in Java. Large-scale SCADA softwares have been used in the automation industries for more than a decade. It is an industrial measurement and control system consisting of a central host or master terminal unit (MTU) with one or more field data gathering (acquisition), control units or remote terminal units (RTU) and a software application used to monitor and control remotely located field data elements. SCADA systems is utilise predominantly in long distance communications, although some elements of short distance communications may also be present. Similar systems to SCADA are routinely seen in factories, power stations, treatment plants and so on. These are often referred to as Distributed Control Systems (DCS). They have similar functions to SCADA systems, but the field data acquisition or control units are usually located within a more confined area. Data communication in DCS is high speed and it uses LAN (local area network). A SCADA system generally covers larger geographic areas, and rely on a variety of communications systems that are normally less reliable than a LAN. The monitoring and control of SCADA systems may be automatic or initiated by operator commands. Data acquisition (DAQ) is accomplished by RTU field inputs connected to the RTU, and it is a fast rate. The SCADA host will scan the RTU's and the processed data is used to detect alarm conditions.