WorldFIP Network Helps Citroën Build Automobile Doors
BUS OF THE MONTH: WorldFIP
C ompetitive pressures in the automobile industry drive manufacturers to continually search for new ways to lower production costs while attempting to improve the quality of products. Since control systems account for a critical segment of manufacturing equipment, new ways to lower costs and simplify control system implementation are considered and usually very carefully examined by systems engineers.
eripheral equipment–mainly the I/O systems–could be improved. Beginning with meetings in 1993, Mr. Leblanc and his group began to seek better ways to connect PLCs with the machines they control.
The project: fieldbus installation
After careful study and evaluation, Citroën engineers decided to install fieldbus systems based on WorldFIP networking protocol. They decided to begin in the plant area where automobile doors are fabricated. The process involves welding, metal forming, and sealing, with tight coordination of large robots to move the doors between work stations.
Reducing floor space
Fieldbus use has translated into immediate benefits for the factory-floor workers, according to Mr. Leblanc. Cabling was reduced by 20%, yet only minor modifications were necessary in PLC programming. All previous software was retained. The big savings was in cabinets. Physical size of the PLC was drastically re-duced. PLC cabinets went from five doors to one door, he says, improvingmachinery visibility. Citroën engineers now envision the ‘evolu-tion towards zero cabinets.’ Mr. Leblanc says the next step in this path might be to elimin-ate TBX modules entirely, and embed the WorldFIP protocol directly into the robots with an ASIC (application specific integrated circuit).
Plastics Producer Chooses WorldFIP
David Slingsby, Cegelec Industrial Control Products Div., Staffordshire U.K.
N an-Ya Plastics, an Anglo-Taiwanese collaboration, has installed a state-of-the-art control system in its plant in Louisiana, USA. The new control system allows Nan-Ya to produce very high quality plastic for a variety of consumer goods, demanding use of high-speed machinery operating under very accurate control.
ach with three sections: calendar, mixer, and strainer. For each machine, there were five PLCs, three operator interfaces, 27 ac drives, and two supervising personal computers.
ss heavily loaded. The network is more reliable, due to its immunity to electromagnetic interference and its dual redundancy.
WorldFIP at a Glance
John W. Beeston, director of international communications, WorldFIP.
W orldFIP is a full-function producer-consumer style fieldbus started in 1987 (as FIP) by EXERA, a group of multi-industry users. Now a European Standard, it is supported by the international WorldFIP nonprofit association. Major vendor promoters include Cegelec and Groupe Schneider.
three types of traffic in a single connection:
Cyclic: Always transmitted on-time, e.g., for closed-loop control.
Events: Transmitted when occurring, e.g., for alarms.
Messages: Transmitted when required, e.g., download of set-ups, upload of diagnostics.
Products & Services
Levallois-Perret Cedex, France– WorldFIP has been fully implemented into Cegelec’s midrange Alspa 80-35 PLC, allowing easy integration with other WorldFIP compatible devices. Data can be exchanged at speeds up to 1 Mbit/sec for distances up to 1 km (copper or fiber optic networks). By offering two independent physical network connections on each node, the WorldFIP module allows dual-redundant network systems to be implemented with ease. Cegelec
Rueil Malmaison, France– The object of the FipConnect program, developed by Schneider, is to integrate third-party products into FIPIO and WorldFIP architectures. It enables any partner organization to develop a WorldFIP connection on its own equipment. The program covers assistance with de-velopment and provides develop-ment tools, validation, and interoperability tests, as well as promoting the solution. Equipment developed under the program benefits from all the advantages of FIPIO and canstill be used in other WorldFIP environments. Schneider Electric
FIPway Under Windows
Drancy, France– The Applicom PC2000FIP card for ISA PCs is equipped with a processor for communication between Microsoft Windows (3.1, 95, and NT) applications and WorldFIP devices using the FIPway protocol. The Applicom server on the PC2000FIP card is available with application program interfaces–FastDDE (Wonderware), AdvanceDDE (Rockwell Software), DLL, and OPC (OLE for Process Control). It is pro-vided with a card configuration tool,as well as test and diagnostic programs. Applicom International SA
Paris, France– FIPWatcher is a low-cost protocol analyzer that acquiresand displays frames running on theWorldFIP bus. It can also capture error frames. FIPWatcher software datesand displays all frames and gives in-formation on their type and content.The package consists of a PC/ISA cardand software that runs under Windows3.1 or 95. HLP Technologies Circle 254
FIP RemoteI/O System
St. Orens, France– The LT100 is a compact I/O system for WorldFIP. Each rack accommodates up to 15 separate modules for a total of 960 digital or 240 analog inputs. Each module mounts on a DIN rail and includes one functional module (16 or 64 digital in, 16 analog out, etc.). The system can be programmed in C or in Opal, a Windows-based configuration tool. Leroy Automatique