Data historian built for batch processes

When the term “data historian” is mentioned, most users visualize x-y plots of process variables scrolling across a screen. If the process is batch, it takes patience and perseverance to map process variables to batch events, such as when a phase started or ended, an operator responded to a system prompt, or an alarm occurred and cleared.

When Fisher-Rosemount Systems (FRS, Austin, Tex.) began designing the DeltaV scalable control system, it did so with batch and continuous processes in mind. Integrated throughout DeltaV’s basic design are “hooks” and “handles” that allow other applications to capture exactly what is happening as it occurs. During configuration DeltaV uses these hooks to determine what information should be shared with other applicaitons, such as the batch historian.

No variable tracking required

Unlike other systems, DeltaV does not require users to assign and track variable use for each configured module. This eliminates time consuming reengineering, retesting, and revalidation to avoid register misuse. Embedding these functions in each module’s source code ensures easy reusability, a key benefit when developing flexible batch solutions.

When users require a tracking mechanism not already embedded in a DeltaV module, “actions” can be defined and attached to the module. Still, no register tracking is required, and reusability is easily achieved.

Tracking mechanisms are not confined to control modules. Consistent with S88 batch standards, DeltaV provides a standardized phase logic interface with embedded event tracking. Operators can Start, Hold, Fail, etc. any phase with automatic tracking of each command and response. Operator confusion, when presented with multiple choices, is eliminated with dynamic color changes in the standard phase logic interface.

DeltaV’s inclusion of embedded tracking mechanisms, from base control through recipes, reduces engineering time and facilitates a true built-for batch historian.

Batch historian uniqueness

Real-time and historical process variable information is presented in a traditional x-y chart using the embedded OSI Software’s (San Leandro, Calif.) PI-System application. Batch event data are presented in a Gantt chart-like format. (See photo.)

Each chart bar is dynamic and double clicking on a bar permits drilling down for additional event information.

Data are available in table format beneath the Gantt chart, and automatically highlighted to correspond with the selected chart bar.

Ability to filter data on batch ID, start-, end-, and span-times, and 30 other predefined elements, illustrates the extensive library of embedded tracking mechanisms available.

DeltaV’s batch historian permits combining batches into a single hard copy report, a useful feature when a product goes through intermediate processing steps before becoming a final product. Using drag and drop, batches with different IDs can be assembled and printed as one report including bar and x-y charts.

Custom batch reports can be created using Visual Basic to access the batch historian database and assemble the batch report in Microsoft Word.

Batch processing users who have been “making do” with continuous historian applications, should take a close look at FRS’ DeltaV offering.

For more information, visit www.controleng.com/freeinfo .

Author Information

Dave Harrold, senior editor, dharrold@cahners.com

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