The TELEPERM M control system set the standard in the 1980s, and while the AS 235/AS 488 controller still performs its service reliably in many plants today, the original OS systems such as OS 265 and OS 525 mostly no longer conform to today’s requirements regarding the display and user guidance and regarding openness towards MES or ERP systems. The objective of a migration is to modernize the existing installed base in a step-wise manner and without a system change while simultaneously protecting existing investments for as long as possible. For this purpose, Siemens began in 1996 to offer its customers optimized migration solutions for the transition from TELEPERM M to SIMATIC PCS 7.

The range of migration products includes not only hardware and software components but also services for converting application software, on-site modifications, and whole-plant migration.


To start, customers concentrated their migration activities on step-wise modernization and on functional expansion of individual components of the existing TELEPERM M system: 

  • OS migration TELEPERM M Replacement of operator control and monitoring systems OS 252, OS 262, OS 265, OS 520, and OS 525 with WinCC/TM-OS or PCS7/TM-OS

  • System expansion with SIMATIC PCS 7/merging of TELEPERM M and SIMATIC PCS 7

  • Replacement of controller level: Replacement of automation systems AS 220, AS 230, and AS 235 with future-viable automation systems AS 388/TM and AS 488/TM while retaining existing application software and TELEPERM M I/O devices

  • Complete replacement of TELEPERM M components and, thus, direct migration from TELEPERM M to SIMATIC PCS 7

OS migration TELEPERM M

PCS 7/TM OS is the answer to the specific modernization demands for operator control and monitoring systems: Here, a modern OS replaces the aging OS 262, OS 265, and OS 520/525. Automation system and field connection level remain unchanged. The OS configuration data can be converted with the aid of a tool; users obtain the up-to-date SIMATIC PCS 7 operating system with uniform adaptation to communication and functionality of TELEPERM M.

System expansion with SIMATIC PCS 7

For system expansions, system components of SIMATIC PCS 7 are now used exclusively; existing TELEPERM M E/A devices continue to be operated in parallel. When old and new systems are merged under a common new OS level, operating personnel can benefit from the uniform look and feel of both systems.

System expansion and merging of TELEPERM M and SIMATIC PCS 7 system components are possible via the following: 

  • Common operator control and monitoring via two-channel OS (PCS 7 and TM)

  • Gateway for AS-AS communication

Replacement of controller level

Process I/O and automation level, including modules, wiring, power supply, and application software, represent a high value that must be preserved. This objective is well-supported by the PCS 7/TM-EA migration package and the services offered within this context for onsite AS conversion as well as for conversion of the user structure of the TELEPERM M automation system to a SIMATIC PCS 7 structure.

AS migration means that engineering data optimized over many years are largely preserved: 

  • Tool-supported conversion of engineering data with high-performance software tools by experienced migration experts

  • Conversion to any target libraries and standards

  • All SIMATIC PCS 7 functions can be used

Complete replacement

In order to benefit from all the advantages of the SIMATIC PCS 7 process control system and to avoid future spare part shortages for TELEPERM M systems, a comprehensive modernization in a single step may be perfectly appropriate.

In this case, the TELEPERM M system is replaced by the modern SIMATIC PCS 7 process control system, including the I/O modules – even during operation, if necessary, to avoid production outages. In addition, Siemens offers different variants – one involving the replacement of TELEPERM M I/O modules with ET 200 modules in the control cabinet and the other involving the use of adapters.

Advantages of migration to SIMATIC PCS 7

The migration of an old system to SIMATIC PCS 7 pays off many times over: It assures the continuity of process control system investments, makes the systems more efficient and productive, and extends the system service life in a cost-effective manner. Additional winning advantages: 

  • Complete transfer of engineering data optimized over years is possible

  • Step-wise or complete system modernization

  • Future viability assured due to use of a modern and flexible process control system

  • Modern technology reduces the risk of plant outages

  • Increased productivity due to higher availability of the new process control system

  • Reduced costs for stocking spare parts and for maintenance

  • Investment protection based on the Totally Integrated Automation (TIA) concept

  • Use of SIMATIC PCS 7 reveals potential for process optimization, thus increasing production output

  • Resource optimization and quality improvement due to increased information density and quality

  • SIMATIC PCS 7 establishes the basis for connection to a Manufacturing Execution System (MES)