Requirements and installation

Requirements

  • Correct installed WinCC OA version.
  • A license for redundancy is required (redundancy is not supported in demo mode).
  • Two computers with the same operating system.
    Note: Mixing the number of bits of two hot standby redundancy partners (one partner with a 32-bit application and one partner with a 64-bit application) is not supported. In real system operation, the two hot standby redundancy partners must be identical and 64-bit, as a 32-bit server can only be operated as an engineering server. See also Software requirements.
  • 2 network cards per computer for the redundant LAN connection.
  • NIC teaming is not supported. See chapter Hardware requirements.
  • The same WinCC OA version has to be installed on both computers.
  • The WinCC OA projects of the both redundant systems have to be saved with the same name in the same directory.
  • Under Windows the project directory has to be shared explicitly for swapping out/in (Release name = Project name) and you have to set writing/reading rights to the directory; under Linux mountpoints have to exist for the computers - under /nfs/HOST.

Please note the restrictions of following connect- and query-functions in regard to the usage with multiple systems: dpConnect(), dpQuery(), dpQueryConnectAll(), dpQueryConnectSingle()isAnswer() sowie isRefresh().

Please note that following functions automatically refresh values after a redundancy switch and therefor no manual triggering for updating the values is required otherwise the values will be duplicated:

dpConnect(), dpQueryConnectAll(), dpQueryConnectSingle().

When restarting a proxy manager in a redundant project, the connection between the redundant servers might be lost.

In a redundant system, a driver must run on both systems and the drivers must be connected to the same PLC.

Note that the entry for the local host, 127.0.0.1 localhost, must always exist in the hosts file of the operating system.

Drivers, CTRL and all other managers, which should establish a connection to the local Data/Event manager, convert it to "localhost".

In a redundant project the managers must establish a connection to the local as well as the redundant Data/Event manager. Therefore, the manager must either use the manager parameter connectToRedundantHosts or set the config entry connectToRedundantHosts = 1 in the corresponding section of the manager.

Installation

A normal installation of WinCC OA version 3.0 or higher is sufficient for using the redundancy. See chapter Installation for more information on installing WinCC OA. The configuration of a redundant system with WinCC OA is described in detail in the chapter creating a redundant system.

For instruction how to perform a WinCC OA version/patch/service pack upgrade in a redundant system, see WinCC OA Upgrade in a redundant system.