Circlip manufacturing facility where the SCADA system was being upgraded

Traceability technologies and processes are vital but so too are the communications solutions you deploy to make them work.   

Phil Howard of Instrumentation Systems & Services and Eamonn Walsh of Brainboxes explain  

Traceability has always been a primary concern to manufacturers but its importance is ever-increasing with the globalization of supply chains, stricter government regulations, continuous efforts to streamline costs, and the need to provide fast, detailed proof of process information. Being able to track and trace all the conditions in the manufacturing process and tag that information to production batches and shipments gives customers a greater level of confidence.

This is especially important with parts such as circlips – the c-shaped fasteners fitted to shafts to prevent lateral movement of components. They are commonly used to prevent things sliding off and although the retaining metal rings are obviously very low cost, their quality is paramount. For example, a circlip located in the middle of a £2000 gearbox in a £75,000 truck needs to be reliable otherwise its failure could cause a very costly problem.

One of the key pieces of data about the circlip which needs to be controlled and recorded is its temperature profile during manufacturing process. This is usually achieved by discrete temperature controllers near to the furnace which in the past were checked regularly by
staff on the production line. It is now increasingly important to capture a much more detailed profile and attach that data to the particular batch of circlips.

Supervisory control and data acquisition (SCADA) systems can now be used to collate and store all the temperature profile data that customers are looking for including when the temperature has strayed outside a pre-defined band and other critical information such as feed rates, work order numbers and operator comments.

Now the quality systems require that customers can see that the heat treatment of the product is tracked all the way through the process with the graphs for the temperatures and, vitally important, no alarms triggered for the batch.

Manufacturing circlips involves a number of complex processes. From the feeders that ensure consistent flow rates to multi-zone furnaces, oil or salt quenching, phosphating and rinsing. This means there can be a double-digit number of controllers on each furnace line. Typically, there would be multiple production lines and many other standalone processes. A central SCADA controller would have real time links to all these controllers in their hostile environments.

In one particular circlip manufacturing facility where the SCADA system was being upgraded there was also a need to replace communications hardware that was experiencing failures due to age. The prevalent technology at the initial time of installation was multiple RS-232 ports each with an isolating RS-232 to RS-485 converter and involved all the associated ‘cable spaghetti’.

Using the Brainboxes ES-571 Ethernet to RS-485 converters allowed the reduction of cabling from 16 RS-232 ports down to a single Ethernet cable. This solution not only simplified the installation, but increased reliability and allowed far greater flexibility in positioning the SCADA computer in relation to the communications equipment.

The new improved SCADA system engineered by ISS and using Prodigy software developed by Tascomp soon proved its worth to such an extent that the client requested it should be integrated into the annealing area of the factory. This wasn’t a major obstacle either financially
or logistically because the ES-571 enabled use of the existing Ethernet infrastructure. This meant there was no need for any additional installation costs or expensive cabling work to worry about.

Commissioning

Using the fully isolated RS-485 offered by the ES-571 completely rules out any possibility of interference having any impact on the validity of the data being collected.

The inclusion of a Brainboxes SW-005 four-port switch and standby ES-571 means that in the unlikely event of a failure, communication can be restored with the absolute minimum of downtime. All Brainboxes Ethernet to Serial devices in its industrial range are suitable for an operating temperature range of -30ºC to +80ºC. This was a key reason why Brainboxes equipment was selected because the original equipment had begun to experience many heat related failures.

Brainboxes’ systems are designed and built in the UK which is another important benefit when it comes to service support. If something doesn’t work, it is essential to know why and get it fixed as quickly as possible. Getting to speak instantly to the people that designed the equipment – such as the ES-571 module – is priceless. And as a result, the hardware commissioning took just one day.

Results

The new SCADA system was able to show that the control of the furnace temperatures could be improved to a much tighter +/-1º. This has reduced the quantity of alarms generated and also highlighted other areas of quality improvement such as overfeeding of product.

The new SCADA system also allows more people to be aware in real time of operations happening on the factory floor. The SCADA software emails everybody on a distribution list with a list of alarms in the last 24 hours and emails supervisors if an unaccepted alarm has been triggered for more than 30 minutes. A new touchscreen PC on the factory floor also allows the operators to easily access the data in the SCADA system.

All of this allows production to run more efficiently. It provides the end customers with proof of process reports in the greatest possible detail and management information to further improve efficiencies and quality.