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Entry type: FAQ Entry ID: 16827826, Entry date: 04/09/2014

What are the requirements for performing an online delta loading of the OS?

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  • Delta loading of a PCS 7 OS station is possible only if Runtime is activated on the appropriate computer. In the case of redundant servers, both servers must be in Runtime. The Standby OS is also loaded automatically and the OS terminal stations (OS clients) are provided with the current "package" (project data).
  • Each OS station must be completely downloaded at least once. In the case of redundant OS servers, the identical OS project version must be completely downloaded on each server.
  • Delta loading of an OS station is possible only for the OS server.
  • If changes have been made on the client project (authorization in the User Administrator, for example), the OS terminal station (OS client) must be downloaded explicitly. However, downloading an OS terminal station is possible only in the form of a complete download.


  • Detailed information about delta loading is available in section 10.1 "Online Delta Loading" of the manual "SIMATIC Process Control System PCS 7 Compendium Part A - Configuration Guidelines (V7.1/V8.0)" in Entry ID 63187279.
  • The various displays of the "Download OS" dialog are described in Entry ID 26460191.

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