Phillip Morris one of first to use PROFINET CBA

Philip Morris International has become one of the first companies in the world to implement PROFINET Component Based Automation (CBA). By modularizing a tobacco conditioning process in a pilot plant at its facility in Neuchatel, Switzerland, Philip Morris International expects to achieve more efficient control of the complex processes involved in cigarette manufacturing and a more flexible response to changing production requirements.

Tobacco conditioning is critical for ensuring consistent characteristics of the cigarette. It must compensate for seasonal and climactic influencess or overdue deliveries from specific regions. It must have the capacity to adapt production to constantly changing fashion and consumer tastes. Finally, it must take into account short-term fluctuations in demand. In the pilot project, new tobacco blends and processes will be developed. Production processes are approximately ten times larger.

The plant comprises stations provided by various manufacturers for storage, weighing, moistening, cutting, blending, flavorizing, refining, and drying an extremely wide variety of unconditioned tobacco leaves. These stations are linked via conveyor belts and vibration belts. One purpose of the pilot is to formulate test blends. Another is to modify and optimize existing lines. This second process is important for two reasons. First, to achieve optimum results, the parameters of each station must be continuously adapted. Second, it is often necessary to replace entire stations with new and improved solutions.

For the drying process, in particular, innovation cycles are very short and process results vary greatly in practice, thus requiring frequent station replacement. Moreover, plant components from different production sites are often interchanged in order to utilize investments as long as possible. All of these factors prompted Philip Morris to completely redesign its facility using an entirely modular concept based on PROFINET CBA. This is based on the principle of complete separation between control logic programming and the configuration of communication connections. To this end, ready-to-use machine or device programs are encapsulated. The user specifies which variables are to be available on the interface of each component. These variables are linked graphically to establish communication links for the user. This eliminates explicit programming of communication.

PROFINET CBA provides seamless communication of Ethernet and PROFIBUS. PROFINET defines a cross-manufacturer communication and engineering model and also specifies how the engineering of communication connections takes place on the application level. With PROFINET, Industrial Ethernet and TCP/IP are used for less-time-critical communication between higher-level devices, whereas PROFIBUS DP can be used for real-time tasks in the field. Special network gateways with a PROFINET proxy function are available to link Industrial Ethernet and PROFIBUS DP. Thus, all conventional PROFIBUS devices (standard slaves and intelligent devices) can be integrated 'as is' in PROFINET communication on Ethernet.

Implementation

The automation component of the new facility was implemented by ISIS (Industrial Software and Information Systems) - an experienced system integrator in the tobacco industry head-quartered in Treviso, Italy. ISIS has close ties to Garbuio, another Treviso-based manufacturer of tobacco-conditioning machines that also supplied parts for the Philip Morris test facility.

ISIS and Garbuio formed an ideal team for creating machine modules, encapsulating their software, and developing a functioning automation structure. ISIS actually applied the component-based approach to encapsulate all user programs of the silo/feeder, tunnel belt, dryer, add-back, flavor cylinder, pivot belt, and direct conditioning and casing cylinder.

Each unit has been equipped with an IP65/67-degree-of-protection SIMATIC ET 200X distributed I/O module with an integrated PLC. These have a PROFIBUS interface and are linked to a higher-level, redundant, fiber-optic Industrial Ethernet ring via a SIMATIC Net IE/PB link with proxy functionality. The IE/PB link enables communication between PROFIBUS devices, as well as with any higher-level Ethernet devices. The specific role of this component in this case is to establish communication to a SIMATIC S7 300 PLC, which coordinates all unit controllers.

To this end, a PROFINET communication module, the SIMATIC Net CP 343-1 PN, was added to the S7-300 to connect to the Industrial Ethernet ring. Also connected to this "coordinator CPU" is the entire safety engineering in the field, which is based on AS-Interface Safety at Work. All plant parts are displayed on two higher-level WinCC servers, which provide current process data to several clients on site via Ethernet.

Graphical Configuration of Communication

From a software standpoint, the centerpiece of the component-based approach is the SIMATIC iMap engineering tool. This enables the user to combine modular application units from different manufacturers. The configuring engineer imports all software components with PROFINET capability into the tool and places them in a library. They can then be added to the configuration diagram using a drag-and-drop operation, and the inputs and outputs of components can be linked simply by drawing lines between them.

All required communication relationships are defined in this way, without the need for complex and time-consuming programming steps. Components are displayed on the configuration diagram of the engineering tool independently of the bus system. Thus, the configuring engineer can concentrate on the technological process. In addition to data for communication links, the engineering tool also generates data for access from visualization systems or standard IT applications. Finally, devices are connected to the relevant bus systems in the network view. Once they are downloaded, the communication connections are activated in the individual automation and field devices. HMI stations can also be integrated in the project via drag-anddrop operations. Pictures can then be configured with the visualization software and linked to the technological software components in the usual way.

The plant is commissioned online with the engineering tool, which integrates the appropriate test and diagnostic functions for this purpose. Adjustments can be made during commissioning without placing any limitations on the functions of individual modules. This facilitates the procedure considerably, as adjustments can be made merely by optimizing the plant-wide interaction of modules, rather than changing the software of individual devices and controllers.

25% Savings Potential

A major advantage of PROFINET CBA is that it enables plant parts frequently required for this concept to be preassembled along with the machine construction. This reduces the number of steps that must be carried out (usually under deadline pressure) at the facility and separates them from the less-time-critical configuration and programming procedures. Instead, this work can be carried out directly at the mechanical equipment manufacturer, and ready-to-use componenents can be acceptance-tested in advance. Once a program has been optimized, it can be transferred to same-design machines without modifactions, or easily adapted to similar requirements.

ISIS estimates the savings potential of this initial component-based application at Philip Morris to be at least 25% - which does not even take into account the greatly improved planning reliability that enables far more efficient implementation of resources.

In daily practical applications, modularization and the relatively easy-to-implement encapsulation of machine programs enable plug-and-play-type replacement of individual plant parts with minimal downtime. Likewise, sources of error can be readily identified, which in turn facilitates quality assurance procedures. Control of sensor and conveyor drives as well as machine-to-machine communication are carried out via PROFINET and thus require no additional interfaces. This translates to consistent mechanisms, greater plant transparency, and improved availability for system diagnostics.

A (Trans)Portable Solution

The test facility operator has reported excellent results thus far, which have already led to the first follow-up projects in 'real' production. A new automated tobacco conditioning process based on the pilot facility is currently being planned. In addition, the European headquarters of Philip Morris International has given the go-ahead for modernization of an existing Primary using this new technology. And as for the Mini-Primary in Neuchatel, there are plans to convert it in the near future to an installation in which the different machine modules are directly linked via controllers with PROFINET capability.

By: Andreas Kumperling, who works for the Siemens Competence Center, Food & Beverages, Nuremberg, Germany and Dr. Peter Wenzel, Director of the PROFIBUS User Organization headquartered in Karlsruhe, Germany. Reprinted from PROFIBUS Interface Center's 'Connection' magazine ( www.sea.siemens.com/pic)

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