Standard Profits: Make2Pack and ISA88
David Chappell is chair of the Make2Pack/ISA88 Part 5 standards development effort, with Complete Manufacturing Automation Associates - LLC, and retired Proctor & Gamble section manager for batch technologies. Help ISA88 committee members increase dialog about, completion of, interest in, and use of Make2Pack. Join in with your comments or questions to help the standard along, on your way to gaining competitive advantage, reducing overall costs by half. David A. Chappell, Make2Pack chair, and other ISA88 Part 5 committee members provide intelligence and specific links for this effort, spanning OMAC, WBF, and ISA standards efforts.
NOTE: ISA grants permission to post portions of the ISA88 (or other applicable standards) in this blog for comments and discussions and postings (or comments) from this blog may be used for ISA and related standards development.
ISA88 Part 5 draft: Traditional automation designs for batch recipes
April 30, 2011
A series of discussions follow seeking input on possible language in ISA88 Part 5 draft standard, Figures 1-5 follow. Please provide comments at the bottom of this posting to ensure the standard is understandable, appropriate, and useful across industries and areas of control, machine control, batch control, and continuous control, as well as flexible and scalable, across hybrid applications.
To help in understanding the focus of Part 5 it is beneficial to discuss some of the dominate traditional approaches used to design, develop and deliver automation used to support ISA 88 batch recipes. The following discussion points provide insight into many of the different traditional approaches used in delivery of ISA 88 modular systems and contrasts those approaches with the recommendations of Part 5.
- Traditional Equipment and Control Modules are custom engineered composites of automation components designed to meet the requirements of a functional strategy (FS) as represented in...
Figure 1: Traditional Automation Module.
- A functional strategy may consist of a totally custom design and implementation or it may utilize components provided by the suppliers of the automation control equipment as represented in Figure 2, which uses a function block provided by a vendor to implement a motor starter. The IEC 61915-2 specification provides methods to interact with function block described as part of that standard and can significantly reduce the amount of custom effort required to implement a FS. As indicated in Figure 2 there is generally additional functionality required to deliver the FS than is provided by the function blocks and the engineer must add that functionality and the methods to interact with the FS of that module. Often the methods and interfaces provide by the function blocks are not appropriate for general use and as part of the additional functionality the module must manage what is exposed and mange interaction with the components used to deliver the FS.
Example of some additional functionality: Simulation, management of permissives and interlocks, ability to bypass the function block and manipulate the outputs directly (Part 1 Automatic and Manual Mode), initialization functionality, alarm management, etc.
Figure 2: FS using vendor supplied function block
- Traditional modules may contain clearly defined methods that allow them to be commanded and controlled from an external source to carry out the functional strategy as represented in Figure 3. In some instances the interactions are obscure and require deep understanding of the FS implementation to be able to interact with it as indicated in Figure 4.
Figure 3: Clearly defined command and control
Figure 4: Obscure command and control
- Command and control encompasses all the external interfaces, data in, status and data out, and commands to activate or change states and behavior as indicated in Figure 5: Command and Control Interfaces.
Figure 5: Command and Control Interfaces
- These command and control methods are generally custom and are generally deep within the custom automation and require detailed understanding of the FS and the implementation to successfully interact with the module.
Next post will discuss Figures 6-12.
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