Migration of control systems

Heterogeneous automation landscapes

Due to the long lifecycle of systems and the acquisition of production locations, many companies today operate control systems from different manufacturers and different generations. While modern systems mainly use open or standardized interfaces, such as Ethernet, OPC or fieldbuses, and rely on standard operating systems like Windows for engineering and operator controls, this is not the case for older systems:

  • Engineering and operator systems use proprietary hardware and software that is partially not supported any longer.

  • Proprietary communication interfaces, for example, between HMI, controllers and I/O modules, make data exchange and communication harder.

  • Standardized interfaces (for example, OPC) are only available as additional functions added at a later time, which makes it more difficult to connect to higher-level archiving and production control systems.

  • Engineering can only be standardized to some degree due to the different systems.

  • Different display, operating and alarm philosophies make the daily work of the operator harder, especially in critical situations.

Heterogeneous automation: In addition to modern control systems (right) there is a number of older, proprietary systems connected by different interfaces

This gives rise to even more problems:

  • The many different systems require an expensive spare parts inventory

  • Spare part supply and support by manufacturers of the old systems slackens or gets more and more expensive

  • The know-how of the old systems is slowly disappearing – for users of the systems as well as manufacturers


All this builds up the pressure to modernize the control systems. Another goal during modernization is to drastically reduce the number of systems that have to be maintained to one or only a few new system platforms in the migration.

Given the central role of the control system for production and the high costs of a control system update, a long-term, planned and gradual approach to the topic, which means the development of a migration strategy for one location or even the entire company, becomes indispensable. The central questions for this process are:

  • Which production lines with older control systems will most likely stay in operation and for how long?

  • Does the respective control system meet the current and foreseeable requirements regarding functionality, flexibility, expendability, interfaces to higher-level MES/MIS systems?

  • Are spare parts and support still available ?

  • What about the in-house know-how regarding handling and maintenance of the old system?

By answering these questions, you can determine which systems have the greatest need for modernization.

For some systems, you may be able to extend the life through corresponding service contracts with the manufacturer. For example, Siemens has started the "APACS 2020" program, so customers with APACS+ or Quadlog automation systems are relatively safe for the next few years even though APACS+ and Quadlog systems have been totally discontinued.

Modernization with a powerful partner

But a migration may be called for in other cases – a modernization whose goal is not only to ensure availability of the control system into the future, but to also start a new generation – which means using the diverse features and options offered by the systems of today.

Based on an in-depth analysis of the existing installation(s), we recommend a migration strategy that specifically meets your conditions and goals.

  • Which systems should be migrated to SIMATIC PCS 7 as a high priority and which can be migrated at a later date?

  • Which migration strategies (complete replacement or stepwise migration) are best suited under the current conditions?

  • Which benefits can be generated from a tool-based implementation of the existing engineering?

  • Which options for control and optimization of your production and the resources required are the results of using a modern control system?

  • Which return on investment can you expect from the migration to SIMATIC PCS 7?


As a powerful supplier of process control technology that is operating in many countries, we have experts that can use their experience from a variety of migration projects to find the right approach for your plant. These experts that work in our "Migration Support Centers" (MSC), our technical support or in the ranks of our experienced partners, are not only familiar with our SIMATIC PCS 7 control system but also have an extensive background in the migration of older systems – not only from Siemens but also from other manufacturers.

This means that with a partner like Siemens you cannot only "tackle" one single migration project if you wish, but also develop a comprehensive migration strategy stretching across several years and many locations that will bring you a critical step closer to the modernization and standardization of your control system landscape.

Complete or stepwise migration

Depending on the state of the existing automation and your goals, we offer a wide variety of migration solutions and products for stepwise or complete migration of older control systems to SIMATIC PCS 7.

For old Siemens systems, including Teleperm M, APACS+/Quadlog, TI505, PMC/OpenPMC and SIMATIC S5, we offer a complete range of migration solutions on every level (HMI, controller, field level, and engineering). You can find more information HERE [link to site].

But, of course, older systems from other manufacturers can also be migrated to SIMATIC PCS 7. Depending on the existing system, there are stepwise concepts in addition to a complete replacement:

  • In addition to our PCS 7 operator station PCS 7/90 OS that was especially developed as operator control and monitoring system for old Bailey Infi90 controllers, our universal, OPC-coupled PCS 7/OpenOS is the ideal solution for modernization of the operator level in all systems that provide a corresponding OPC server. This is true for other process control systems as well as PLC type control systems. In all these cases, the existing operator control can be conveniently replaced with PCS 7/OpenOS – as part of a modernization or for integrating existing controllers into an automation solution with SIMATIC PCS 7. [link to OpenOS]

  • The replacement of older controllers with modern PCS 7 controllers is the crucial step of migration: They will give you a noticeable gain in performance and functionality. A test to see if we are able to save time and reduce costs to a significant degree by using our powerful migration tools for controller engineering is certainly going to be part of this step. Our experts convert the existing engineering, that has been optimized for years to SIMATIC PCS 7 in such a way that it is just like engineering from scratch: Not block for block but on the level of technological functionality. This means you get to keep the valuable know-how of the old system and still have unlimited access to all functions of the new control systems.

  • The replacement of I/O modules and the associated wiring with thousands of process signals takes a long time and is cost-intensive. But in many cases, manufacturers support the I/O modules of old systems longer than other components or you will still have a large inventory of spare parts available. In these cases our flexible solutions for integration of other I/O modules in SIMATIC PCS 7 or cable/connector solutions can effectively facilitate the connection of existing field cables to our ET200 modules.

You can see: With our experience and solutions we will be able to find the best answer even for the migration of your old system.