Secure Operation! A Control System with Fail-Safe Backup

A Truly Batch-Ready System with a Fail-Safe Backup Plan
Creating and implementing a batch system that operators can run manually if the batch system is unavailable
Background

Avid gets a lot of these requests! A producer of specialty chemicals contacted Avid to design and deliver an Emerson Delta V control system. This system needed to provide automated batch processing capabilities. The challenge was to design a system capable of manual operation in case the system failed.
 
The company was replacing an existing batch system. The development of the new system required complete operator buy-in.  These requirements prevented an installation using conventional batch configuration techniques. The system needed to eliminate risks from a batch system failure or operator errors.
 
The proposed system would incorporate the basic concepts of the S88 standard for batch process control. S88 provides a consistent set of standards and terminology for batch control. S88 also defines the implementation of the physical model and procedural model. S88 permits system designers to create a universal model for batch control. In this case, strict adherence to S88 would not provide the functionality that the customer required.
 
This implementation required operators to have the ability to manually run process phases. S88 standards encompass layers of programming. These layers begin with continuous control and then move to procedural control:

  • Control modules
  • Equipment modules
  • Phases
  • Operations
  • Unit procedures
  • Procedures
The Delta-V Batch Executive controls the procedural layer. It handles all recipe management, arbitration, and sequential management. The continuous logic executes at the controller layer.
 
Why choose Avid for this project? The client chose Avid for the following reasons:
 
  • Experience with specialty chemical process applications.
  • Unparalleled process control expertise.
  • Ability to recognize and solve complex system and process challenges.
  • A proven history of exceeding client’s expectations.
  • A can-do attitude. Avid acts like an end-user.
Approach

The DeltaV Batch Executive is a software application runs on a peripheral server. The server is a single point of failure.
Avid Solutions developed a program that included all programming levels. The design also allowed manual control of the physical DeltaV functions in the event the Batch Executive failed.
The configuration integrated with the client’s graphic and operator interface standards.

System

To meet the challenges outlined above, Avid modified the configuration. This modification moved phase control to the equipment module level.
This allowed operators to start and stop the equipment modules without having to start a phase.
Avid engineers created custom logic to manage the communication between the DeltaV Equipment Module layers and the DeltaV Batch Layer. This change resulted in failure propagation. Failure propagation is not typical when the Batch Executive fails.
 
The new system allows operators the ability to set recipe parameters at the equipment level in the event of a batch system failure.
When running, the Batch Executive enforces default recipe parameters. This produces consistency in product quality.
The new operator interface now allows the operator can to alternate between running with the batch system or manually. The end result is that the system is set up for the best results possible in either situation. This flexibility allows quick reaction to unforeseen process upsets, reducing any lost production.

Applications:
  • Batch
  • Processing
Technology:
  • DeltaV
  • S88
Technologies
“We approached Avid Solutions with a uniquely difficult task of creating a fully batch-ready system with all of the benefits of batch processing that could also be manually operated, if needed. Their manufacturing floor and processing experience led them to deliver exactly what we needed.”

Results

With batch processing solutions, this company gained quality standardization and optimized production.
Risks associated with cross-contamination and human error were minimized.
The validated batch control system ensured consistent performance and adherence to regulatory standards.
Avid’s solution also provided operators with the flexibility to react to adverse conditions.
 
Need a robust and reliable batch control system that provides operators flexibility and ease of use? Contact us!

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