Make2Pack’s S88.05: Continuous control to packaging

-- Control Engineering, 4/17/2007

West Chester, OH—The standards effort aiming to unify and streamline connections from continuous process control and batch control into discrete packaging re-energized recently. Progress on Make2Pack and ISA's S88.05 included increased attention to its packaging roots with help from OMAC PackML members, better explanation of the effort, clarification in terms, and resumption of monthly in-person meetings.

According to telephone/Web and in-person committee meetings in March and April, Make2Pack chairman David A. Chappell said goals include picking up the pace, engaging more participants, and ensuring the resulting standard continues to gain interest through demonstration efforts and is eventually adopted. Efforts include work on a technical report, which requires a lower level of consensus than a standard and can give participants a strong early starting point for better understanding.

Using the S88.05 modular unified software design concepts can result in 50% savings in development time and engineering resources for new systems and line modifications, with greater preservation and reuse of intellectual assets. The operational visibility and improved operational control will also greatly improve recovery time from system upsets. A mini tutorial that includes other benefits is below.

Progress from meetings in March and early April included:

• Agreement for OMAC efforts to team up with ISA-88 Part 5 standards group to ensure work is complementary. Eventually documents must and will converge. Chappell noted that an OMAC PackML technical report is a companion effort to Part 5 workgroup efforts. "We've heard concern that efforts have become more process in orientation and packaging is losing out to process. We definitely don't want that to happen. The intent is for the resulting standard is to meet packaging as well as process needs to show how abstract standards apply to the real world."
• Revision of a table of S88 and Make2Pack terms aimed to address concerns that use of continuous process terms may have confused those with roots in packaging.. Updates to the table hadn't been made for about nine months, noted Randy Dwiggins, Maverick Technologies, who was part of the team that broke up long blocks of text, eliminated obsolete terms, and made it more digestible.
• Designs such that the industry can leverage the wealth of material in libraries that already exist.
• More communications with the S88 committee.

This diagram shows interactions with a generic automation module, using still-evolving thinking involved in OMAC PackML, Make2Pack, and S88 guidelines and standards, as of early April.

March meeting in Cleveland included discussion of IEC standards approach where definitions will be incorporated in the body narrative. Once the group agrees on the informative language, normative language should follow, broken down into conformance and compliance. The process intends to ensure more efficiency in standards making.

S88 Part 1 working group also is making significant progress incorporating recommendations to clear up some potential areas of misunderstanding of the true intent of S88 Part 1. Dave Emerson, Yokogawa, is applying concepts of procedural control and management. Make2Pack co-chair Dan Seger, Rockwell Automation, is helping with language relating to the continuum of control.

"All of this will lead to great things in near future with ability for systems to interact and intercommunicate without significant engineering effort," Chappell says.

Mini-tutorial: S88, a continuum of control
S88 provides a continuum of control with separation of different types of control. A control component contains control software as part of a Cell, Unit, Equipment Module or Control Module. It may be a product or custom created. Types of control in the continuum are equipment basic control, equipment principle control, procedure aware equipment principle control, operation procedure control, unit procedure control, and cell procedure control.

As the graphic shows, things outside the module can interact with module in a secure, controlled, and safe manner. Traditional control usually doesn't address ownership issues; the Resource Manager and Function Manager provide a method to handle these interactions and a method to manage resources. This ensures that if multiple users issue a command, it doesn't create system upsets, allowing asynchronous sources access. (Historically this has been a problem with additional supervisory HMI interactions. With an appropriate model, an HMI could possibly provide much of the wrapper.)

Committee work and relation presentations will be part of the World Batch Forum at the end of April.

For other upcoming meetings, and committee contacts, see the Make2Pack Website.

—Mark T. Hoske, editor in chief,
Control Engineering Weekly News
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