Integration of package units

Transcription

1 Presented at the World Batch Forum European Conference Brussels, Belgium October S. Southgate Drive Chandler, Arizona Fax Integration of package units Ferenc Molnár Manager BatchControl Ltd Dugonics u. 11. Budapest, H-1043 Hungary (36) (36) Tibor Chován Associate Professor University of Veszprém POB. 158 Veszprém, H-8201 Hungary (36) x4209 (36) x4171 KEY WORDS Batch control, S88.01 models, Package unit ABSTRACT One of the current problems of batch automation specialists, especially in the pharmaceutical industry, is the integration of PLC-controlled units (package units, e.g. centrifuges, dryers) into -like control systems maintaining homogenous structure. On the basis of IEC :1997 standard Workgroup 2 of Hungarian Batch Forum prepared a draft Proposal for users and manufacturers of package units that suggests different methods for the integration of package units. The paper discusses the integration from a system-architecture point of view while the communication problems of control equipment are not considered. Integration at unit recipe level: PLC-controlled equipment can run recipe, provides only recipe or parameters. Integration at operation level: runs the recipe, operations are executed by PLC-controlled equipment. Integration on the phase level: executes all tasks except phases that are executed by PLCcontrolled equipment World Batch Forum. All rights reserved. Page 1

2 In the paper the advantages and disadvantages of different levels of integration are compared. Also, suggested parameters for interface between & package are provided. Results: Optimal way of integration. For users: simple, clear and unambiguous specification of integration with package unit to be ordered. For manufacturers: simple, clear and unambiguous specification of integration with to be provided. Reduced programming and installation efforts. For operators: simple way of working. 1. INTRODUCTION The typical system architecture in pharmaceutical industry, especially in the production of active ingredients, uses Package Units for system building or extension. These units are self-controlled and mostly PLC-based units. The typical final processing plant in pharmaceutical industry consists of a crystallizer, a centrifuge and a dryer. Centrifuge is usually available with own control; also more and more dryer manufacturers offer their own PLC-based control equipment for their units; on the other hand crystallizer (or tank reactors in general) rarely has its own control system. If the users want to solve their problem with or -like e.g. hybrid control system, they have to decide which tasks to be solved by and which ones by PLC-based Package Units. In either case users must face the problem of integrating self-controlled units into one system. Some users are frightened by the problem and will not even try the integration. The PLC-controlled Package Unit remains an isolated piece or equipment rather than an integrated part of the overall manufacturing facility. Attempting the integration after installation is a money and time consuming approach; manufacturers will only undertake to modify tested and validated programs for significant extra price. In this case the user can get in a very exposed position as the risk & responsibility for the correct workings of the package may be transferred from vendor to user. How can Package Units, produced by different suppliers, be integrated into one homogeneous system so that the control strategy of each individual unit and the interface to operators is the same and the necessity of learning and using non-standard solutions, special modes and operational methods is avoided? This proposal discusses principally the system-architecture aspects of integration and does not deal with the communication problems. 2. GOAL OF THE PROPOSAL This proposal intends to help end users to design homogeneous systems, to prepare clear User Requirements Specification and to provide unambiguous purchase order simply, reliably and quickly. This proposal can be given to the manufacturer (e.g. that of centrifuge, dryer, etc.) along with the call for offers. This way considerable surplus labour and extra cost can be avoided. Manufacturers can use this proposal to design and produce equipment matching inherently the requirements for integration. They can also get to know what the user wants from relatively simple and short specification World Batch Forum. All rights reserved. Page 2

3 3. BASIC CONCEPTS The theoretical foundation for the solution of the problem is established by IEC :1997 (ISA S88.01) standard not only by supplying unified terminology but also by providing models which allow a consistent approach. Using this standard the system architecture becomes understandable and transparent and consequently easy to learn and use. Subclause of IEC :1997 standard is considered as fundamental for the development of this proposal. To understand this proposal, the knowledge and application of the process, physical and procedural control models as well as recipes is necessary. 4. SYSTEM INTEGRATION USING THE MODELS The connection between the Package Unit (PLC-controlled) and the central control system (e.g. ) can be described using the above models. The control tasks can be allocated to two possible locations: - central control system (e.g. ), - control device of the Package Unit (PLC). unit procedure operation phase PLC Equipment unit procedure Equipment operation Equipment phase Figure 1 - Possible levels of integration Accordingly three different methods of integration can be chosen: 4.1 Integration at unit recipe level In this case the PLC-controlled system is capable of running unit recipes; the recipe runs in PLC; provides only parameters or recipes World Batch Forum. All rights reserved. Page 3

4 unit procedure 1 PLC Equipment unit procedure operation Equipment operation phase Equipment phase Figure 2 - Integration at recipe level Table 1 Integration variables at unit recipe level Code Function Required Comments from to PLC RecSel selection λ RecPar i parameters λ OpPar j Operation parameters λ RecFirstOp First operation to be executed µ If not defined, then the first operation of recipe RecLastOp Last operation to be executed µ If not defined, then the last operation of recipe RecControl control λ Start, Stop, Abort, etc. ProcAuto* Manual/Semi-automatic/Automatic switch (procedural control) λ Control mode RemLoc* Remote/Local switch λ Control location: Remote control Local PLC control from PLC to MeasValue k Measured values RecStatus status Run, Pause, etc. ActOper Current (running) operation µ OpStatus Operation status µ Run, Pause, etc. BasStatus State of phase level equipment Valves, motors Event l Events Alarm m Alarms µ λ - required * may come from PLC to µ - recommended λ World Batch Forum. All rights reserved. Page 4

5 4.2 Integration at operation level In this case controls the execution of unit recipes, while operations and phases runs in PLC. PLC unit procedure operation 2 Equipment unit procedure Equipment operation phase Equipment phase Table 2 Integration variables at operation level Figure 3 - Integration at operation level Code Function Required Comments from to PLC OpSel Operation selection λ OpPar i Parameters of current operation λ OpControl Operation control λ Start, Stop, Abort, etc. BasicAuto* Manual/Automatic switch (basic control) λ Control mode RemLoc* Remote/Local switch λ Control location: Remote control Local PLC control from PLC to MeasValue j Measured values OpStatus Operation status Run, Pause, etc. BasStatus State of basic level equipment Valves, motors Event k Events Alarm l Alarms µ λ - required * may come from PLC to µ - recommended λ World Batch Forum. All rights reserved. Page 5

6 4.3 Integration at phase level In this case controls the execution of unit recipes and operations while phases runs in PLC. PLC unit procedure Equipment unit procedure operation phase 3 Equipment operation Equipment phase Figure 4 - Integration at phase level World Batch Forum. All rights reserved. Page 6

7 Table 3 Integration variables at phase level Code Function Required Comments from to PLC PhSel Phase selection λ PhPar i Parameters of current phase λ PhControl Phase control λ Start, Stop, etc. BasicAuto* Manual/Automatic switch (basic control) λ Control mode RemLoc* Remote/Local switch λ Control location: Remote control Local PLC control from PLC to MeasValue j Measured values λ PhStatus Phase status Run, Pause, etc. BasStatus State of basic level equipment Valves, motors Event k Events Alarm l Alarms µ λ - required * may come from PLC to µ - recommended 5. CONTROL MODES AND STATES Batch control systems can be operated in different modes and they can have different states. Application of modes and states described in IEC :1997 (ISA S88.01) standard is recommended. Selected modes should be used consistently, on the basis of the standard and with the same interpretation for each unit. The same applies for the propagation of modes. 6. SELECTION OF THE LEVEL OF INTEGRATION The level of integration for a given application should be selected with the knowledge of advantages and disadvantages as well as considering the possibilities and requirements. To help the selection a few guidelines are given in the following paragraphs and a summary in subclauses Allocating a task into or PLC (dedicated package controller) also determines who solves the problem. If the task is allocated to the then the problem is solved by the software team. If the task goes into the package PLC then the problem solver is the manufacturer (vendor) who, in most cases, has more experience in the control of its own unit. Certain tasks are difficult to solve in the (e.g. special advanced control algorithms which are not included in library). Forcing a task into the 'wrong box' can cause a disproportionately large World Batch Forum. All rights reserved. Page 7

8 amount of resources to be committed. This can also motivate of the selection of a certain (possibly higher) integration level. 6.1 Unit recipe level - (Unit s in Package Controller) Advantage: - Phase and operation level control is developed by the package manufacturer who knows all about the unit. - Relieves the load on. Disadvantage: - Direct manual control of actuators is complicated from. - Unit recipe control of PLC is modest. - Changing or modification of functions solved in PLC is difficult, sometimes unsolvable. - Documentation is complicated; recipe format is different; editing and storing recipes is different, etc. 6.2 Operation level - (Operations in Package Controller) Advantage: - Phase and operation level control is developed by the manufacturer who knows all about the unit. - Unit recipe control of is usually more advanced. - Simple documentation (batch report). Disadvantage: - Direct manual control of actuators is complicated from. - Changing or modification of functions solved in PLC is difficult, sometimes unsolvable. 6.3 Characteristics of phase level integration (Phases in Package Controller) Advantage: - Operations are flexible. - Unit recipe and operation control of is usually more advanced. - Simple documentation (batch report). Disadvantage: - Operations are developed by the user who knows less about the unit. - Labour and time consuming World Batch Forum. All rights reserved. Page 8

9 7. PRACTICAL EXAMPLES At present manufacturers usually prepare their package unit for autonomous operation and not for being integrated in the overall control system. If an interface for integration is provided at all it rarely gives a choice of the level of integration. The following examples represent some of the typical solutions that reflect the manufacturers' experience on the appropriate level of procedural control. 7.1 Integration of centrifuge control Centrifuge control Centrifuge recipe Centrifuge operation Centrifuge phase Figure 5 - Centrifuge example (Comi Condor) World Batch Forum. All rights reserved. Page 9

10 7.2 Integration of dryer Dryer Operation Dryer operation Dryer phase Figure 6 - Dryer example (Hosokawa, Guedue; the case of Ferrum centrifuge is similar) 7.3 Integration of filter-dryer control Filter-dryer control Operation Phase Filter-dryer phase Figure 6 - Reactor example (MAVAG filter-dryer) 8. LITERATURE 1. ISA-S Batch Control. Part 1: Models and Terminology, Internal Society for Measurement and Control, Thomas G. Fisher Batch Control System: Design, Application, and Implementation, ISA, Molnar F, Radacsy F.: Integration of Package Units into -based systems (in Hungarian), IV. Conference, Lillafured, Hungary, Leif Poulsen: Proposal on Guideline for Development of SP88 Compliant Data Models for Batch Management and Control Systems, EBF Seminar, Milano, Liptak B. (Ed.): Instrument Engineer's Handbook, Process Control Volume, Chilton Book Company, World Batch Forum. All rights reserved. Page 10