The decision to use IEC 61131-3 within N.V. Emgo, Lommel, Belgium
IntroductionN.V. Emgo in Lommel, Belgium, is the largest producer of glass bulbs for lighting applications (lamps) in the whole world. Every year over 1.7 billion bulbs find their way to light-bulb manufacturers on all continents. Famous names in the customer base include Philips Lighting and Osram.
The glass bulbs are produced around the clock on four production lines. The fastest line yields approx. 1350 bulbs per minute of type A60. On the other lines larger types are produced at a rate of 600 till 700 bulbs per hour.
In 1994 it was decided to improve the glue lines for the boxes of the glass bulbs. In order to remain one step ahead of the competition it was decided to adopt a newer, more advanced control system with more data communication possibilities. This allows very fast and flexible reaction to call-off orders (just-in-time delivery) and last-minute changes in order size.
The decision processBecause the existing controller line could not fulfil the requirements, a new selection had to be made. Because of the investment for introducing a new controller line, such a choice is made at Emgo for 10 years. This means that not only the equipment should be reliable but also the supplier. And because the investment in the application software is much higher than in hardware, also that the development environment for the application software should be up-to-date and future proof.
In starting such a new application, Emgo has a special philosophy. Mr. Guido Wydaeghe, head of engineering within Emgo, explains: "For new applications we want to add external knowledge, as can be provided by external engineering companies. In this way we can make a major improvement not only in the control but also in our own knowledge. It provides us with a good basis to add in a later phase our own experience and functionality."
Why IEC 61131-3?
Mr. Wydaeghe replies: "The investment in the application software in such a project is much higher than in controller hardware. This means that we must take care to secure this software investment to the future. We evaluated the IEC 61131-3 standard, and as an open programming system we really believe in it. The IEC standard provides us with an excellent broad programming environment, with which we can solve all our programming problems, now and in the future."
After a short pause he continues "Because the IEC standard was relatively new, the number of potential suppliers was limited. And also the number of engineering companies familiar with this standard and capable of developing our application was limited. But, the benefits of using this standard are so relevant and real to us, we believe that this is only a matter of time."
Shortform description of the systemThe system is for the glue lines and the reporting system. The boxes are arranged in series of 25 based on priority, labelled, vibrated to settle the bulbs in the box, closing the boxes and apply adhesive tapes, coding of the tape with an inkjet printer and reporting of production and statistical data to the host VAX computer.
Since 1995 the system runs at Emgo, and to their satisfaction: it helps them to increase the efficiency of the available production capacity. Because the selected PLC system, Philips P8 with PDS-7 as programming system, was relatively new, some start-up problems specific to this application occurred. Due to the support of the supplier, these problems were solved, creating an improved environment for future applications.
Currently Emgo is working at their first changes and additions. Via the
IEC 1131 standard this is simplified for them, because it can be implemented
in easy steps in software and hardware.