Toohey’s took the decision to standardise on Profibus for its brewing and packaging plant in New South Wales. But poor Profibus wiring and incorrect network implementation nearly derailed the can line.
Faced with seemingly unsolvable problems, Tooheys turned to Tyco Flow Control, Australia’s first accredited Profibus International Competence Centre (PICC). Armed with powerful diagnostic tools and a wealth of Profibus knowledge, the PICC team set about fixing the stuttering can line.
With fifteen hundred beer cans rolling off the production line every minute, Tooheys can line at Lidcombe in New South Wales needed a robust automation system. Profibus has been the system of choice at Tooheys brewing and packaging divisions for close to fifteen years.
“In our packaging department, we only buy machines that have Profibus capability,” explains Adonis Malas, Tooheys packaging controls manager. The Brewing Department too uses Profibus extensively to network the instrumentation.
However, despite the company’s exten sive Profibus experience, one of Tooheys can lines set up a year and a half ago and commissioned by external technicians, ran into a host of problems and required ‘outside’ intervention.
As in most breweries, Tooheys brewing unit pipes the beer to the pack aging department’s fillers. The cans are then placed, filled, sealed, pasteurised and shrink wrapped or packed in cartons and placed in pallets.
“The particular problem with this line involved the conveyors — specifically, the line integration or line control system,” explains Adonis. The ‘line’ Adonis refers to consists of a series of discrete but linked machines and includes the filler, pasteuriser, packer and palletiser among others. A Profibus control system running alongside this line integrates the machines and ensures that the cans flow through the process efficiently.
Profibus was implemented on all other Tooheys lines as well, and offered several benefits including savings in wiring, and the availability of a wealth of information from the drives. Profibus also integrated with the Siemens PLCs which are standard across the Tooheys plant.
“We are convinced that Profibus is better suited to a noisy workplace like ours because it is a more robust system,” says Adonis. At the Tooheys plant, Adonis and his team are able to commission and configure devices from one location.
“Diagnostics and troubleshooting are much easier because these functions can be performed from the control room,” adds Adonis. Line control sensors tell the system when the can line is full and thus regulate the conveyor speed.
“The drives themselves act as remote I/O for us,” explains Adonis. “Profibus gives us an added benefit since we do not have to wire all these discrete devices back to the PLC directly or even through remote I/O cards.”
The other major benefit that Profibus delivered was the ability to decentralise the safety system using the ProfiSafe protocol which was integrated and configured very easily. ProfiSafe allows the Tooheys team to pick up emergency spikes up to category 4 level. “Our production line layouts are quite irreg ular and complex,” explains Adonis.
For Adonis and his team there were problems aplenty in the early months caused primarily by improper termina tions, poor network design and incorrect installation.
This resulted in irregular activity on the filling line, incorrect process sequence and production jams — all of which kept occurring in a non-repeat able, random sequence making it all the more difficult to analyse.
A can line is a very wet environment made more so since the line has to be washed down at the end of every shift. Poor installation and a less than ideal hosing down process led to water getting into the variable speed drives leading to faults. “The problem was compounded since we were running ProfiSafe on many of the systems,” explains Adonis. With the occurrence of any Profibus fault, ProfiSafe drops out and produc tion halts until the issue is resolved.
Even environmental conditions such as humidity in the air and moisture in the drives began to impact the operation of the can line. Faced with increased down time and poor performance, Tooheys decided to call for assistance.
“We just couldn’t continue to operate that way. I understand the Profibus system conceptually but could not deter mine the location of the specific faults,” Adonis recalls. “With Profibus, it is diffi cult to see the quality of an installation,” he adds.
Tyco Flow Control, Australia’s first accredited PICC was called in and asked to study Tooheys problematic can line network. Sven Huber, PICC Automation Engineer deployed the powerful ProfiTrace analysis tool and quickly identified three problem areas — incorrect run lengths, wrong segmenta tion and poor terminations.
The first step was to fix the two repeaters and the ProfiHub so as not to exceed the specified lengths. “These were installed, but incorrectly,” says Adonis.
Under PICC’s guidance, the ProfiHub was installed in the middle of the line with the spurs driven off that hub while ensuring that drop lines lengths did not exceed 150 metres in total as specified in Profibus. The repeaters were then relocated to an optimum position.
Huber was also able to analyse several faulty terminations which were problem atic due to water ingress. These were dried out and sealed.
These two changes improved performance but the can line was still running below optimum level. Further analysis with ProfiTrace uncovered another problem — that of incorrect voltage at each node. Tooheys can line network was running at an average of 3 volts as against the 4 to 7 volt range specified for a Profibus network.
Once this issue too was fixed, the can line finally stepped into gear, eighteen months after it was commissioned. PICC’s Huber and his ProfiTrace tool were ultimately the saviours.
But Tooheys is not alone in stum bling upon poor termination problems. This is indicative of a deeper malaise that afflicts many Profibus installations across the country. The industry has been slow to accept the fact that Profibus wiring and installation requires special skills, training and certified technicians.
The Tooheys can line was installed and project managed by a team of external consultants. “The person actu ally terminating the cables on the floor was far removed from any of our internal team members,” says Adonis. “We had no way of knowing if they had any Profibus accreditation at all.”
As often the case, the electricians who run the cables to the drives, lights and equipment are also tasked with laying the Profibus network cables. “They are told to lay some purple Profibus cables too and they place and install them the same way as the elec trical wiring,” says Adonis.
PICC’s Huber is emphatic about the expertise needed when dealing with installing a Profibus network. “Proper termination and installation is vital and must be done by a certified installer to avoid problems like those faced by the Tooheys team,” he says “This is the biggest problem facing our industry,” concludes Huber.
About the PICC
The demand for intelligent automation is growing rapidly in Australia and throughout Asia Pacific.
Profibus is a key component in the successful uptake of intelligent automa tion and the ongoing maintenance of a manufacturing plant.
The Profibus International Competence Centre (PICC) was set up to support technically, the spread of Profibus technology throughout the region.
The PICC will support companies in new product development and will provide technical support for Profibus manufacturers and users.
The PICC’s technical support covers system design, fault diagnosis, design verification, demonstrations of interoperability of products and a comprehensive range of certified training programmes.
Tyco Flow Control has been accred ited as the first PICC in Australia. The Centre’s support framework includes the availability of Profibus experts, hardware equipment from various vendors and system test lab operations.
The PICC is strictly vendor inde pendent, providing an independent service for the implementation of Profibus technology.
Tyco Flow Control also offers the internationally accredited, certified one- day Profibus Installer course.
The course is suitable for engineers and technicians and covers the layout, installation and testing of Profibus DP and PA networks.
A three-and-a-half day certified Profibus Engineers course covering network design, commissioning and live fault finding is also on offer.
Tyco Flow Control’s automation centre contains a variety of control systems and instrumentation for poten tial users and suppliers to become acquainted with the technology using their devices of choice.
These services offered by the Profibus International Competence Centre are completely vendor independent and the sole objective is to support Profibus technology implementation.