Latest News

Full-colour control in print

In a journey spanning five years, Shepparton Newspapers has tripled its colour printing capacity, implemented a complete Rockwell Automation drive and integrated safety control system overhaul, and maximised plant uptime when it’s most needed–in the dead of night.

A crucial vehicle of news dissemination has long been the daily newspaper, spread out across the breakfast table. The ensuing challenge for newspaper publishers–who are now competing with the immediacy of television, radio and the Internet–is how to ensure the morning tabloid contains the most up-to-the-minute information, while still landing in households at the crack of dawn.

This challenge is faced every 24 hours by Shepparton Newspapers, a division of McPherson Media Group, and the publishers of the regional Victorian daily paper, Shepparton News. The essential task of newspaper printing is undertaken by the company’s separate printing division, which takes on the night shift. From the moment the last electronic file is received at 11pm, the heat is on to despatch the first 30 per cent of newspapers to the streets in just an hour and a half.

“It’s definitely all about deadlines and short lead times in the newspaper business,” says Paul Kelly, general manager of Shepparton Newspapers printing division. In addition to the Shepparton News, the facility prints a wide range of other newspapers and advertising material under contract, for which penalties can apply if delivery deadlines are not met.

“Newspaper publishers all want the latest information going to press, preferably before the opposition gets it!”Kelly said.

This places immense importance on the reliability and performance of the printing press. In Kelly’s view, the main KPIs are whether or not the press works, and how fast it can be brought back online when it doesn’t. Moreover, with production runs ranging from 800 to 70,000 copies, printing between four and 120-page papers, production flexibility and the ability to print in full colour are also chief considerations.

According to Kelly, it was ongoing maintenance issues, coupled with escalating demand for full-colour offset printing, that ultimately catalysed a comprehensive upgrade of the Shepparton Newspapers printing press in 2003.

“We were doubling press time to get the number of colour pages we needed, and it wasn’t economically viable,” he says. Five years and two upgrade projects later, the facility has not only tripled its colour printing capacity, but implemented a full drive and integrated safety control system overhaul, based on technology and solutions from Rockwell Automation.

It happens at night

The Shepparton Newspapers printing press comprises a series of vertical printing units, through each of which a continuous roll of paper, known as the web, is fed from bottom to top. As the web passes progressively through the unit, it picks up colours in stages. The units are either a full-colour ‘four-high’, where four stacked elements print cyan, magenta, yellow and black respectively; or a ‘two-high’, where two stacked elements print black and an accent colour. The webs exiting each unit incorporate a group of eight pages (four per side) printed repeatedly. These are automatically overlaid and aligned, before being folded, cut and stacked in the folding machine to form the final individual newspapers.

The primary goal of the first upgrade, carried out in 2003, was to add three new full-colour units, as well as an additional folding machine. Printing press manufacturer Goss International was engaged to provide the new press. This was installed in-line with the existing press, which featured two four-high and several two-high units. Using an innovative clutching system, the lineshafts of the ‘new’ and ‘old’ presses were mechanically linked, allowing them to operate as either one complete machine, or two individual presses, depending on production demands.

The lineshaft is essentially a drive shaft running the length of all the units, to which all press equipment–including the folding machines–is mechanically coupled. As such it is the key driving element of the press. When considering the motor and drive system for the new section of the press, Shepparton Newspapers decided to address reliability issues with the legacy DC drive system associated with the existing press at the same time. Goss recommended Rockwell Automation be appointed to redesign and overhaul the drive and control system as a whole.

“We’d been having all sorts of problems with the existing press–breakdowns once or twice a month that would take two or three hours to fix,” says Kelly.

“These would often lead to production penalties. We had absolutely no technical support for any of the motors or drives, and as a bunch of printers we wouldn’t have a clue as to what we’re looking at! Nevertheless, we needed to be able to get the press back online quickly at three o’clock in the morning. It all happens at night!”

According to Peter Tomazic, Rockwell Automation technical and commercial product manager for global drive systems, it was essential to take a holistic view of the project to ensure that all Shepparton News’ needs were met.

“We looked at what they needed in terms of production flexibility and safety, what they might need if the press was further expanded in the future, and especially what they needed in terms of local service and technical support,” he says. “Every aspect of the solution took these criteria into account.”

In with the new

To replace the legacy DC drive system, Rockwell Automation designed and implemented an AC drive system incorporating five new Reliance RPM AC variable speed induction motors, specially designed to provide continuous torque down to very low speeds. These were coupled with corresponding 93kW (125hp) Allen-Bradley PowerFlex 700 variable speed drives. Two of these motor/drive pairs drive the lineshaft nominally associated with the new section of press (‘Press 1’) and three motor/drive pairs drive the old (‘Press 2’).

The PowerFlex drives are interfaced via ControlNet communications to two Allen-Bradley ControlLogix multi-disciplinary controllers, which provide intelligent drive and logic control. Similarly, each ControlLogix was assigned to control either ‘Press 1’ or ‘Press 2’, with peer-to-peer controller communications via ControlNet.

This control/drive system configuration allows Press 1 and Press 2 to function independently, at different speeds, when the clutch between lineshafts is open. In this scenario, each ControlLogix controller assigns one of the PowerFlex 700 drives per press as the ‘master drive’, which sends torque references to the ‘slave drives’. If the presses are clutched together, one ControlLogix and PowerFlex 700 drive pair takes over as the master and all other PowerFlex 700 drives become slaves, with all driving the same lineshaft.

Operator interaction with the control/drive system takes place via two Allen-Bradley PanelView Plus human-machine interfaces (HMI), connected to the ControlLogix controllers via EtherNet/IP. These allow press setup configurations and lineshaft speeds to be entered, and provide production and drive information to the operators. They also indicate any alarms and faults, and allow interrogation of the system for diagnostics purposes.

“A key part of the total solution was looking at ongoing technical support options,” Tomazic says.

“To address this we brought in local system integrator, Terry Johnstone, to assist with installation and commissioning of the new system.” In addition, a simple Rockwell Automation ‘parts management agreement’ (PMA) was established, where critical spare components of the system (such as a spare PowerFlex 700 drive, ControlLogix processor, and FLEX I/O and ControlLogix I/O modules) are hosted by Shepparton-based Rockwell Automation distributor, Delta Electrical.

“The diagnostics ability and local support has made a huge difference,” says Kelly.

“We hardly ever get unplanned shuts anymore, but when we do, they only last around half an hour. Using the HMI we can identify where the issues are occurring, and we can advise Terry what the problem is before he gets here. The PMA has only come into play once or twice over the past four years, with maybe the replacement of a control board, but it’s good knowing it’s there.”

Split system

Armed with improved colour-printing capacity and a state-of-the-art drive and control system, Shepparton Newspapers’ contract business flourished, until in 2006 a new project was conceptualised to further accommodate the relentlessly escalating demand. “We wanted the flexibility to split the press even further, so we could schedule different sized production runs at either end of the press and utilise all the units most effectively,” says Kelly.

The project involved the insertion of three additional clutch points that allowed different combinations of printing units to be clutched together. This provides greater operational flexibility, with the split no longer limited to being between the ‘new’ and ‘old’ sections of the press. Now, for example, ‘Press 1’ can incorporate three, four, five or six four-high units, depending on what is required for a particular print run, leaving ‘Press 2’ to incorporate the balance as required.

The key challenge, says Kelly, was ensuring that operation of the press remained safe. “It was very easy for me to say exactly what I wanted, but we had to make sure it fit within the safety constraints. Rockwell Automation recommended a risk assessment be carried out, and we thought this was a good idea. The outcome reinforced and clarified the safety issues and gave us a manageable project with specific goals.”

The main safety issues introduced by the project related to the numerous combinations of clutch configurations, which are manually set and entered into the control and drive system via the PanelView HMI. The control system keeps track of which printing units are clutched together, allowing ControlLogix to allocate the required number of drives, including the master drive, for that section of the press. It also must strictly control how the units behave during the ‘plating up’ stage of setup, which is when the printing plates are manually attached to the printer rolls. During plating up, it is essential for operator safety that each print unit’s movement is limited to a locally controlled inching function.

From a safety point of view, it is therefore crucial to ensure that the configuration entered into the control system matches the actual clutch configuration. Should the physical setting be incorrect, the unit being plated up could potentially be called into operation by the other half of the press, creating a serious hazard to the operator.

“We must be 100 per cent certain of the status of each clutch,” says Tomazic. “This was the starting point for the safety control system design. There are simply too many combinations to use safety relays, which is what we used for the first stage of the project. The sheer number of possible configurations introduced in this second stage of the project meant we needed a more sophisticated approach.”

Taking safety seriously

The resulting Rockwell Automation-designed safety control system is founded on the Allen-Bradley GuardLogix safety controller, which has been fully integrated with one of the ControlLogix controllers from the 2003 upgrade. GuardLogix monitors the inputs from a series of paired (for redundancy) Category 3-rated proximity switches fitted to each of the four clutch points. These indicate the actual status of the clutches and must match the configuration entered into the system manually.

The safety audit also revealed several additional areas where safety could be improved, leading to the installation of improved mechanical guarding on the units and ‘safe stop’ buttons on each unit. Inputs for these and the clutch proximity switches are all hardwired into Allen-Bradley safety I/O modules, which are connected via a DeviceNet communications network to the GuardLogix controller.

Tomazic points out that the other great advantage of the GuardLogix safety controller is its ability to initiate controlled shutdown of the press. If any of four ‘emergency stops’ are activated, the safety control system will shut down the entire press. If a ‘safe stop’ button on a print unit is pressed, or a roller guard opened, the section of press clutched to that unit will be shut down in similar fashion.

“The safety control system also initiates a controlled shut if the web breaks, which happens from time to time,” Kelly adds. “In this case, the web is first ejected out the back of the folding machine to prevent it from becoming jammed and potentially damaging the machine. It’s also much easier to start up again.”

According to Kelly, the journey of the past five years has been well and truly worth the effort. With all the upgrade work carefully managed to be carried out during scheduled downtime and maintenance periods, the plant never missed a day’s production. “We really welcome the changes introduced by Rockwell Automation and the operators appreciate the level of sophistication in the system now. With the old drive system, which was all relays and switches, we used to swap a few things around and eventually get the press working again by trial and error. Now we can get the machine back online much more quickly and get back to what we’re good at–printing newspapers.”

For more information, contact;

Ross Vaughan

Rockwell Automation marketing communications manager


Phone: 03 9896 0300


Send this to a friend