Set up in 1963, Victoria-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 an impressive automation plan in a rather creative manner.
In 2001, the company was taken over by Tyco Flow Control, the world’s largest manufacturer of industrial valving and related controls.
In what was still essentially a manual setup 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 its new range of couplings.
“Back in the year 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,” said 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 integrating fieldbus and spread over several years, while keeping the plant running.
Implementation challenges
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 eventually chose Profibus.
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-screen interfacing directly on the bus.
“The wiring topology of Profibus is a single twisted pair,” he said.
As his Profibus networks began to expand and increase in complexity, Brady called in Australia’s only accredited Profibus International Competence Centre (PICC) which was established by Tyco Flow Control Pacific.
Grant Weyman, Technical Services Manager – Controls at PICC, did an audit of the installation at Wang Components. Using the ProfiTrace 2 analyzer, 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 downtime through better diagnostics. It simplifies routine maintenance and supports preventive maintenance,” explains Weyman.
Commissioning the various devices at the Wang Components plant was indeed simple 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% and Brady was able to achieve a precise weld at a remarkable speed of around 1m/min. Process time dropped to approximately 25 seconds, 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 Profibus’ fieldbus 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,” explained Brady.