- Optima Control Solutions was tasked with replacing an ageing recipe-control system with a modern batch control solution
- Allen-Bradley ControlLogix programmable automation controllers
- EtherNet/IP device-level ring network topology
- Batch servers
- Rockwell Automation integrated-display computer running FactoryTalk View Site Edition (SE)
- Rockwell Software FactoryTalk Batch software solution
- Reduced obsolescence risk
- Reduced downtime
- Quicker and easier migration
- More robust interlinked network
- Server based solution
Addressing obsolescence is an issue facing many companies and failure to create a robust action plan can often lead to problems that not only affect the operation of a line or machine, but can also result in unfavourable issues that could have detrimental effects on quality levels and brands.
The dangers of obsolescence were identified early on at a leading British biscuit manufacturer in its mixing plant, where older hardware was not only showing its age in terms of performance and failures, but was also no longer part of a supported spares regimen.
To address this issue, the biscuit manufacturer approached Rockwell Automation, the manufacturer of the ageing legacy system, who collaborated with Blackburn, UK-based Optima Control Solutions Limited.
Optima Control Solutions was involved due to its comprehensive experience of similar applications combined with the fact that it has undertaken numerous similar upgrade projects and has in-depth knowledge of Rockwell Automation products and solutions.
Like many similar conversion projects, downtime at the mixing plant had to be kept to an absolute minimum. This meant that Control Solutions needed to complete the upgrade project during weekends and other periods of downtime, provide a solution to reduced overall downtime, minimize implementation risks and still offer an operational solution when production was required to ramp up again during the upgrade.
This was achieved by working on the new system during the weekends, then disconnecting it and removing major parts every Sunday evening so the legacy system could resume on the Monday. The system integrator also had to react quickly, as it only had a two month window, from order placement to delivery and installation.
The age of the solution also played a part in creating a challenge. The engineers knew the control system and the operators knew the mixing process, but even with this combined knowledge, it was tough to create a full specification that met all of the manufacturer’s goals. This was overcome with significant interactions with the staff at the plant, which resulted in solution that would serve the needs of all parties.
In addition, rather than just remedying the problem with a standalone solution, Optima Control Solutions also needed to address the coding and recipe control/delivery system and replace it with a batch-server based concept.
Ultimately, this would not only address the short term obsolescence issues, but would also give the biscuit manufacturer the ability to enhance its production control and reporting capabilities. Data could also be backed up and a familiar look and feel for the operators could be maintained for future upgrades.
The migration programme was to take place over three non-co-located mixing lines that feed a significant part of the end user’s plant. At the actual mixing stations, it comprised the replacement of Allen-Bradley® PLC-5® controllers and ageing Allen Bradley 1784-T30C Plant Floor Terminals with Allen-Bradley ControlLogix® programmable automation controllers (PAC) and SCADA systems with FactoryTalk® Batch clients feeding off a modern server-based batch management solution.
According to Mark Lane at Optima Control Solutions: “To maximise system availability we designed and deployed an EtherNet/IP™ device level ring connecting the ControlLogix PAC on each of the mixing lines in a robust factory level network with the Batch server.
An additional Batch server was configured as a backup server. Each mixing line has a Rockwell Automation integrated-display computer running FactoryTalk® View Site Edition (SE) supervisory-level HMI software with a Batch client accessed via an ActiveX. The local PCs are used to select and start recipes on the Batch server. Batch then dictates the quantities of each ingredient and the sequence of mixing operations.
“In operation, the central server loads the recipe and batch data to the controllers and the controllers manage the mixing process,” he continues. “Thanks to the EtherNet/IP network, The Connected Enterprise solutions feeds these process-specific parameters back to the servers – and to the company’s SAP system – for logging, quality control and historical analysis. Another interlinked controller was used on the bulk feed stem too.”
Optima Control Solutions also implemented the Batch solution in accordance with S88 standards as requested on the functional design specification. Recipes are executed from the FactoryTalk® Batch software and the operations required to make product are broken down into phases and allocated to equipment modules. When executing a recipe, multiple phases can execute simultaneously on different modules.
The recipes that are used also follow the principles of S88, with each product requiring a Master recipe, which can only be created by authorised personnel. These Master recipes act as templates to create individual batches. To produce a batch, a control recipe is created from the relevant Master recipe and can be adjusted as necessary to create the batch.
“When we developed the first of the systems,” Mark Turner, Engineering Director at Optima Control Solutions explains, “the intention was to fully utilise the features of FactoryTalk Batch so it would create a batch record of each control recipe, storing time-stamped default and user-specified information about the batch as it is made. Typically with these systems a new batch would be created and then started for each mix of product.”
However, the customer operates its mixing differently. The customer requirement is for a recipe to be selected, a batch created and started and then the recipe steps in this batch to be repeated continuously until the operator selects that the recipe should end. Optima Control Solutions was able to use the FactoryTalk Batch software to achieve the same workflow, which was the biscuit manufacturer’s top priority.
"We have significant experience of these sorts of upgrades and were able to bring this experience into this job. The conversion process itself is made immeasurably easier thanks to the migration solution Rockwell Automation has developed. These include a swing-arm wiring conversion system, developed to help users migrate from legacy PLC solutions to modern Allen-Bradley® ControlLogix® controllers. Test and commissioning of the system took place over several weekends to fit around the needs of production. On each Saturday morning we removed the PLC5 rack and replaced it with the ControlLogix rack, and swing arm adapter kit. Then, on the Sunday evening we reversed the process, leaving the PLC5 in control, so that production could continue. Using the conversion kit this change-over was completed in less than 45 minutes.”
The swing-arm adapter solution from Rockwell Automation not only makes migration projects easier, but thanks to conversion modules, it also makes them less prone to error through the reuse of existing wiring. It is also quicker – in a rack containing ten 32-I/O module slots, savings in the range of 10 hours per rack are not unheard of.
The new server-based batch solution running FactoryTalk Batch software, in conjunction with the higher performing ControlLogix controller, has delivered exactly what the biscuit manufacturer required: a future proof control concept that also gave it much deeper insight into its batching and recipe-control procedures.
“This was not just a ‘sticking plaster’ to address the immediate issues,” Lane explains, “but an expandable, future proof solution which gives the customer better batch tracking and more consistent batches. The biscuit manufacturer not only has greater visibility of its processes – with the HMI screens showing all primary processing steps – but it will also be able to reduce downtime due to system errors. This is complemented by a reduction in operator errors too, with regards to how each of the batches ‘work’, thanks to comprehensive data displays and the fact that every mixer now uses the visual system and layout – breeding plant-wide familiarity.”
By upgrading to a modern process solution, end users will see multiple benefits. Initially, the risk of potentially damaging downtime through the failure of ageing hardware is removed. They also gain access to the extra capabilities and performance inherent with modern process systems. They will also see increased throughput, reduced maintenance costs and better security and quality.
Improved productivity forms one of the primary foundations of the Connected Enterprise, which end users can exploit thanks to contemporary hardware connected via modern protocols, such as EtherNet/IP. This increase in productivity is bought about by access to real-time information, upon which informed and actionable decision can be made.
“Rockwell Automation is a site standard at this location,” Lane concludes. “And for batch processing it is my belief that Rockwell Automation supplies the best technical solution. We also benefited from its technical capabilities too, with a batch specialist helping us to implement this application.”
Allen-Bradley, ControlLogix, FactoryTalk Batch, PanelView, PLC-5, Rockwell Automation and Rockwell Software are trademarks of Rockwell Automation, Inc.
*EtherNet/IP is a trademark of ODVA, Inc.
Trademarks not belonging to Rockwell Automation are property of their respective companies.