System Figures of Merit

Future Expandability:

The selection of equipment, standard software and networking shall be such as to offer optimum flexibility for future expansion without affecting the system reliability.

Fault Tolerance:

The system shall be designed to operate in automatic or semi-automatic mode of operation under failure conditions.

Spare Capacity:

The system shall have sufficient capacity to perform all functions as required. A minimum of 30 per cent of the total memory shall be kept unallocated for future use.

Loading:

The data highway shall be designed to be optimally loaded and the same shall be clearly indicated in the offer.

Software Structure and Quality Programs:

shall be in high level language that is effective and economical for the proposed system in respect of Modularisation, rate of coding, store usage and running time. The software structure of the system shall be suitably distributed/centralised for supervision and control of the related process areas following the state of the art architecture.

Integration:

The communication software shall be such that the systems shall be able to communicate independently among themselves as well as with the lower level Basic Control/Process control automation system, as required. Provision shall be made for interfacing the production control system with the higher-level Business Computer system to be provided for the entire steel plant in future.

Programmability:

The information system shall generally be designed such that it shall be possible to change the data items and log formats without undue interference to the system.

Data Integrity and Protection:

Logged information shall be stored for adequate time period ensuring the availability of historical data record. Data captured by the system shall be checked for integrity with respect to their validity and plausibility with annunciation. Storing of essential data to be protected against corruption when the system loses power supply or during failure.

Points to Ponder: 2

A. The above specification document was developed while ordering for the automation system solution for an advanced rolling mill. Compare the functional divisions of the Basic Level and the Process Levels with that of Levels 1, 2 and 3 as discussed in this course.

B. Name three additional functionality requirements of automation systems that you may not have found earlier.

Appendix B: Features of an Industrial DCS: Honeywell’s' Total Plant Solution (TPS) System

Honeywell offered a new generation DCS system christened Total Plant Solutions (TPS) in 1996. The fundamental characterizing feature of the system is the unified environment for business and control. The system is highly integrated, and Honeywell has provided solution from sensing to real-time control to process optimization to batch scheduling and inventory control. In other words the same system supports all level 0 - level 3 function without any very distinct structural boundary. The integration is achieved through a virtual network, which seamlessly integrated a PC based plant wide intranet such as Ethernet, and the process networks such as Honeywell’s LCN and UCN or Foundation Fieldbus. Technologically, it uses state of art hardware and software standards such as window NT, OLE, Fieldbus, Power PC/Intel chips, ODBC (Open Database Connectivity). The new components in the TPS system are the following.

· Global User Station

· Total Plant Desk Top

· Total plant equipment tools

· Total plant history

· Advanced suite of application software for Multivariable Control

· Optimization and Batch process Management

Global User Station (GUS) is the interface to the open business environment. (GUS) is designed to be the Windows NT GUI for all Honeywell Control Systems - TPS as well as TDC 3000. GUS is a Power PC and a process network processor (LCN/UCN). Power PC run all window NT software. The network processor, which is a PCI bus plug-in-board on the Power PC, controls the secure control environment. It runs Honeywell’s RNOS (Real-time Network OS). Thus it is possible to organize and operator interface controlling data both from the Business and the Control Environments. Application software is all based on window WT and support all Microsoft Tools such as OLE, SQL, OBDC, netDDE and video. TPS manages a common database, which shared by controllers in client server architecture. For realizing Level 1 functions TPS has a High Performance Process Manager, Fail Safe Controllers and supports high density I/O, the LCN and fieldbus networks. Between the open environment and the secure control environment is a `firewall’, which prevents the degradation of real-time control by other application due to excessive intrusion and resultant constants improved on resources such as network bandwidth or CPU time. The following are among the Software Packages provided.

· Historian

· Advanced Control Solution for a range of Industry Application.

· Desktop tools provides tightly integrated interfaces to Microsoft

· Excel and Access for Power Trend Analysis.

Honeywell has entered into a strategic alliance with SAP American Inc for integration of business modules for sales procurement, order entry, production invoicing and shipping, with TPS for a tight enough to business and control

Points to Ponder: 3

A. Name three areas of software technology that have significant impacts on modern DCS solutions.

B. What are the advantages of Open Standards compared to Proprietary Standards, in the context of Automation systems?

Lesson Summary

In this lesson, the following topics related to higher levels of automation have been discussed.

A. Production Planning and Control

B. Supervisory Control

C. Distributed Control Systems (DCS)

D. Example functional specifications for Level 2 and Level 3 automation of a large industrial process

E. Features of a modern Industrial DCS system

Answers, Remarks and Hints to Points to Ponder

Points to Ponder: 1

A. How is ERP (short for Enterprise Resource Planning), popular software-based technology related to Level 3 automation?

Ans: ERP is a software technology to integrate all aspects of information related to operation in an organization including its manufacturing and business aspects. It is thus the enabling technology on which Level 3 and Level 4 automation systems can be implemented and integrated. This is evident from the fact that modern DCS systems support interfaces to standard ERP products.

B. The above description of Level 3 automation is given mainly in the context of discrete manufacturing. Do you expect different features for continuous manufacturing processes, such as a refinery or a steel plant?

Ans: For continuous manufacturing, such as refinery and steel, generally, product variety is lower, while production volumes for are high for individual products. Variations in product levels are also slower. It is for this reason, that, longer range scheduling is possible and is somewhat easier. On the other hand, these processes being highly energy intensive and requiring continuous material transformation, synchronism between operations in various units can have big impact on quality and productivity. In general it can be said that, aspects of Level 3 automation may be simpler in process plants, but aspects of Level 2 automation tend to be more complex.

Points to Ponder: 2

Ans: As mentioned in the specification document, the Basic Level shall cover control of all equipment, sequencing, interlocking micro-tracking of strip for specific functions, dedicated technological functions, storage of rolling schedules and look-up tables, fault and event logging etc. Centralised supervisory and monitoring control system shall be provided under basic level automation with dedicated processors and MMI. All necessary signals shall be acquired through drive control system as well as directly from the sensors/instruments as, required. The Process Control Level shall be responsible for computation and control for optimization of operation. Functions like set point generation using mathematical models, learning control, material tracking within the process line/unit including primary data input, real time control of process functions through basic level automation, generation of reports etc. shall be implemented through this level of automation. Therefore, basic level includes both Level 1 and Level 2 functions. Process Control Level includes Level3 functions and some functions that may be called Level 2.

B. Name three additional requirements of automation systems that you may not have found earlier.

Ans: Apart from functionality requirements, there are several IT related require on automation system products. Some of these mentioned above are: Future Expandibility, Software Quality, Data Integrity and Protection

Points to Ponder: 3

A. Name three areas of software technology that have significant impacts on modern DCS solutions.

Ans: Database, Networking and Decision Support

B. What are the advantages of Open Standards compared to Proprietary Standards, in the context of Automation systems?

Ans: Open Standards promote competitiveness among vendors and provides maximum value to the customer, in terms of functionality, quality, reliability and cost of automation systems. Adoption of such standards imply that the customer can purchase equipment from a variety of vendors and integrate into the overall system without difficulty. Proprietary standards were followed earlier by big automation vendors and have largely been replaced by open standards today.