Obsolescence of control systems

After almost 30 years from the first PLCs and 20 years from the use of PC in the supervisory systems, many articles have been written about this matter and about the correct procedure to list and monitor the plant component status. But despite the numerous articles on the subject, most of all in Small and Medium Enterprises the problem remains.

Personally, I like to underline another aspect, yes, the material becomes older and with difficulties of replacement but to me it is more important the loss of knowledge of the systems due to the turnover increasing and the retirement of the engineer that 20/30 years ago have built the control system.

Focus on that SADAS group, with more than three decade of experience in the customization of control systems, has specialized its engineer with continuous knowledge training policy. A control system integrator like SADAS is a great source of help and advice, because of the knowledge and because the continuous relation with the main component suppliers.

Customer orientation is the driving force behind our company

SADAS can combine solutions to avoid the total replacement of parts and combines the replacement of equipment with the renewing of what is in place, aiming to propose the best solution at the lowest cost. In the paper sector, a sector in which SADAS was born and has grown, the problem of the obsolescence of the equipment as described is very urgent to be addressed.

On the one hand, however, if replacing the old PLC (like SIEMENS S5) with the new S7 systems or the Simatic 1500 is considered a fairly routine, with a lot of applications already done, it is not so for DRIVE control systems or for those DCS systems with a closed environment system supported with difficulties also from the main suppliers. It is especially here that the knowledge of SADAS on products and processes acts successfully, providing the customer with a valid and specialized economic alternative.

Some examples

In the European paper mill typically, you will find two main technical environments: SIEMENS or ABB with the same issue and possible solution. Specifically, in the ABB world, SADAS has recently optimized and started the replacement of the machine drive control keeping the power part as is giving to the customer a very competitive solution.

The problems

• An obsolete but still repairable drive made with many ACS600 and other ACS800;
• The needs to make changes after mechanical modification of the system with the addition of new drives (ACS880);
• The needs to modernize a plant with an obsolete APC control system and to implement a new diagnostic more appropriate to the times;
• And last but not least the need to have a single company who took all the part of the assembly, changes to the panels, sw and start-up.

SADAS was able to guarantee the personnel for the necessary modifications and replacement of the networks already in the pre-stop phase. Then, technically:

• The old APC’s control panels and the supervision made with an old AC450 have been eliminated;
• The new communication interfaces have been inserted, restoring the existing optical fibers to the existing ACS600 and ACS800 DRIVE;
• A new 800M CPU has been inserted with the related communication cards and the new control panels;
• Connected and interfaced with the new and old DCS paper mill system (in this case 800xA and AC450).

The plant started up successfully with the new OPEN drive application software that SADAS has developed over the years.

What does OPEN drive SW mean? It is very simple. SADAS’ SW do not use property blocks, but just the standard library and then perfectly verifiable and maintainable in short and specially in long term. In addition, the new SW allows more up-to-date diagnostic techniques, first out alarm and other, allow an immediate fault analysis from the panels and the HMI. It is important to underline that the choice to maintain an ABB solution has been linked to the presence of the ABB DCS in the paper mill. It would also have been possible to completely change the control system to switch to a SIEMENS control CPU in case of request and especially in case of greater competence of the maintenance technicians. Similarly, in another way, more and more old SIEMENS systems with old SIEMENS controls (such as SIPRO or similar) have been replaced with ABB 800M controls. This is to say that today a modern system is no longer bound to an existing type of brand or product. With the knowledge it is now easier to choose also mixed solutions with the goal to provide the best of each product facilitating the maintenance engineers in their daily jobs. And it is precisely the knowledge that SADAS makes available to the customer.