Wang Components takes the integrated way with Profibus

Set up in 1963, Victorian-based Wang Components was initially involved in the water pumping and irrigation business before moving into the manufacture of quality clamps and couplings. Over the past few years, the company was able to use the features of Profibus to implement a creative automation plan.

In 2001, the company was taken over by Tyco Flow Control, the world’s largest manufacturer of industrial valves and related controls. In what was still essentially a manual set-up at that time, Wang Components operated a cut-to-length machine, a dedicated milling machine and a dual welding system.

With business expanding rapidly, the company decided to automate some specific processes to meet demand for their new range of couplings. “Back in 2000, I visualised where we would like to be in the next five to ten years in terms of equipment, safety considerations, workflows and production processes,” recalls Allan Brady, Works Engineer at Wang Components. The many specialised but interlinked functions within the factory, and the need to satisfy customer requirements made rapid transformation impossible.

So instead of a grand master plan implemented overnight, Brady rolled in a series of process upgrades with integrated fieldbus spread over several years, while keeping the plant running. The first challenge was to get the various required devices to communicate with each other. Brady spent a fair bit of time researching various communications protocols and discovered that none could match Profibus on speed.

Once Profibus was selected, next came the issue of resources. “How could I wire up the entire factory, and the variety of devices and welding technologies, using just the internal resources at our disposal?” he recalls. Fortunately, Profibus offered a relatively pain-free solution with minimal wiring and could use HMI touch screens interfacing directly on the bus. “The wiring topology of Profibus is a single twisted pair,” he says.

As his Profibus networks began to expand and increase in complexity, Brady called in Australia’s only accredited Profibus International Competence Centre (PICC) which has been established by Tyco Flow Control Pacific. Grant Weyman, Technical Services Manager - Controls at PICC, did an audit of the Profibus installation at Wang Components. Using the ProfiTrace 2 analyser, Weyman was able to check the complete Profibus network with one software package and one piece of hardware.

“Profibus dramatically increases asset management effectiveness and reduces down time through better diagnostics. It simplifies routine maintenance and supports preventive maintenance,” explains Weyman.

Commissioning the various devices at the Wang Components plant was simplified by using the GSD files supplied by the vendors. With the Profibus implementation, Wang Components has also been able to share its resources on the shop floor, such as welding power sources, to suit production requirements.

One of the first repetitive tasks that Brady attempted was to weld a 316 stainless steel BSP socket onto a 316 stainless steel tapping band. The task averaged 3-4 minutes manually. The automated system had to pick, orient, place and weld the socket - a job that needed to be extremely accurate, fast and repeatable. The implementation of Profibus opened up all the machine variables through a single communication port. The difference between a good weld and ‘blowing a hole’ is around ±1 to 2%, but Brady was able to achieve a precise weld at a remarkable speed of around 1 m/min. Process time dropped to approximately 25 s, matching the tact time of other stages allowing a progressive build production flow.

The implementation was not without its fair share of teething problems - right from noisy power supplies causing electrical interference to a byte-swapping phenomenon. The first issue was quickly solved by installing a common power supply through the system, including the power to the Profibus nodes. The byte-swapping problem took some solving. The eight bits in the byte, when sent down the Profibus cable, were being received in reverse order. “It was easily fixed with one line of software in the PLC,” explains Brady.

Despite a seemingly dream run, Brady does have one regret. “We made the mistake of not implementing Profisafe,” laments Brady. The decision to implement Profisafe must be taken very early because it determines what type of CPU you purchase. “Most of our systems were implemented before Profisafe was available”, he explained.

Overall, Brady is delighted with the end result - a successful and well-run facility that is well positioned to modernise and grow even further. The company recently implemented a state-of-the-art plasma fusion process to weld thick materials. Wang Components took the smart decision to embrace Profibus early on and managed a staged introduction through their production process without missing a beat. “I counted on the transparency and horsepower of Profibus and my faith wasn’t misplaced,” concludes Brady.