PID Tuning Support for Tablet Coating Machine

Client: Pharmaceutical company, UK

Background and Objective

A UK-based pharmaceutical manufacturer was facing performance issues with a tablet coating machine. The client required a quick response and a technically deep understanding of automation theory, particularly around PID (Proportional–Integral–Derivative) control. The goal was to diagnose and correct problems in the existing setup that were leading to product losses and operator intervention.

Challenge

The process was unstable, with batches being lost due to poor PID configuration. Operators had to manually intervene during production, adjusting controls by eye without any data to confirm whether the system was behaving correctly. The client needed the issue resolved urgently, and the technical complexity required advanced expertise.

In fact, another company had already declined to take on the job, considering it too small and too technical, as it involved investigating and improving a third-party system.

AG Controls’ Role in PID Tuning Support for Tablet Coating Machine

AG Controls was brought in to perform a diagnostic of the current setup and implement the necessary corrections. The team was able to respond quickly, even while handling other projects, demonstrating the advantage of AG Controls’ team-based engineering model compared with a single-contractor approach.

Our Technical Approach

The work focused on detailed PLC programming and PID setup and tuning. AG Controls:

• Conducted a full diagnostic of the existing PID configuration.
  
• Analysed the PID output in detail rather than relying on visual inspection, providing hard proof of how the system was performing.
  
• Challenged the current configuration and implemented targeted corrections to stabilise the process.

The engineers spent two days on-site with the customer, following all required pharmaceutical procedures during setup and tuning.

Results and Value to the Client

The project achieved its objectives with clear measurable outcomes:

• No more loss of product batches.
• Operators no longer have to intervene – the process now runs automatically and reliably.
  
• The client was so satisfied with the results that they requested additional PID systems across their facility to be checked and tuned using the same approach.
  

Conclusion

This short-turnaround project demonstrated AG Controls’ ability to deliver precise automation improvements under tight deadlines. The intervention provided the client with a stable, verifiable process and removed the need for manual adjustment – leading to greater consistency, reduced waste, and higher confidence in production performance.