Having standardised on Beckhoff industrial PCs from Hayes Control Systems, Rizla, the UK's largest supplier of cigarette papers, found that the versatility of these compact yet powerful products made possible the implementation of an innovative plant monitoring system.
For the engineers at Rizla, the decision to use Beckhoff CX1000 embedded industrial PCs (IPCs), as the basis of the control systems on key production machinery was an easy one to make. Not only are Beckhoff products approved by Imperial Tobacco, Rizla's parent organisation, the CX1000 units also offer a range of important technical benefits.
For example, their modular design allows them to be easily adapted to suit different types of machine, their small size makes them easy to accommodate, and their attractive pricing makes a significant contribution to keeping project costs under control.
Response speed is also a significant factor. On the paper packaging machines, for instance, a vacuum head is used to pull the first paper slightly out of the pack, so that the users of the papers can easily take hold of it.
The process is triggered when the vacuum reaches the requisite level, as indicated by an analogue signal fed to the controller. The CX1000 is required to evaluate this signal and reliably initiate the appropriate actions in just a few milliseconds.
At Rizla, the CX1000 IPCs quickly proved their worth as control devices in a variety of applications and, to date, they have been installed on six drum gumming machines and two five-packers.
The drum gummers apply gum line to the paper at a rate of 60 metres per minute, equivalent to almost a million cigarette papers per hour. The five packer machines load papers into packets, and then put five packets into a box, ready for sale. Each machine produces 120 packs per minute.
Work is also currently in progress on implementing a CX1000-based control system for an interleaving machine. This will make full use of the motion control facilities provided by the CX1000 to provide fast, accurate point-to-point control for a 6A servo drive.
Always seeking ways of improving productivity and efficiency, Rizla's engineering team quickly realised that the IPCs controlling their machines had access to a large amount of data which would be invaluable in monitoring and evaluating plant performance.
Because of the excellent data handling capability and communication features provided by the CX1000, accessing this information was a straightforward task. It was important, however, that it should be delivered to production and maintenance personnel in a convenient and easy-to-use form.
After careful consideration, the solution adopted was to install an Altitude web server, also supplied by Hayes Control Systems, which is linked to the CX1000 IPCs via an Ethernet network. Working with Visual Basic, Matthew Hall, an in-house IT programmer at Rizla, produced software for this server which presents plant information in the form of a series of web pages.
The front page provides access to data archives, and to the site analysis function. When site analysis is selected, a page displaying a detailed site plan is called up. Mouse clicking any of the key areas of this plan effectively zooms in to provide an instant overview of the operational status of the CX1000-controlled machines in that area.
Machines that are running are displayed in green, while those that are stopped are shown in red. Mouse clicking on an individual machine provides more detailed data.
In the case of the gumming machines, for example, the screen shows the type of product being produced, the paper speed, temperatures at key locations, and the amount of paper processed. All of the information is displayed in a user-friendly graphical format.
For the packing machines, the detailed information includes the calculated efficiency of the machine, the guard status, the number of boxes produced and the total downtime. The screen also incorporates a "faults" button, and clicking this shows all of the principal fault modes of the machine, and the number of times it has stopped for each of the faults.
"Thanks to the versatility of the Beckhoff products, the implementation of our control systems and of the monitoring system was straightforward," said Neil Davis, "and the support we received from Hayes Controls was also excellent at every stage of the project. This is particularly gratifying as, in the past, we have had severe support problems with some other suppliers of automation products."
So successful is Rizla's plant monitoring system that plans are under consideration to extend its capabilities. One option, for example, is to track the amounts of raw materials used by each machine. When usage reaches a predefined level, the Altitude server will send an email to the PDA of one of the supply operatives, who will then bring a pallet of the appropriate material to the machine.
This will help to minimise changeover time, and will contribute toward optimising Rizla's just-in-time systems.
Rizla's applications clearly illustrate the versatility of Beckhoff CX1000 industrial PCs. Taking full advantage of the power and economy of modern PC technology, combined with the fast real-time performance provided by Beckhoff's unique TwinCAT software, the controllers are capable of simultaneously handling conventional control functions, multi-axis motion control and data processing.
They are easily interfaced with Ethernet and with virtually all fieldbus systems, and are programmed using familiar IEC61131-compliant languages, making them an ideal choice for virtually every industrial and commercial application.