TCP/IP Communication

The different WinCC OA managers need some free port addresses for the communication through 'TCP/IP Socket Connections. A port address is a sophisticated sub categorization in addition to the IP address of the computer. In addition to the address, you distinguishalso the port (for example 192.167.123.12:4999) so that different program packages can communicate through TCP/IP. Two different programs can not communicate through the same port! WinCC OA uses the following ports by default:

You can detect a collision of a port address with existing programs already at the beginning - PMON or the managers do not start correctly. In this case you can assign the used port addresses individually to WinCC OA.

Windows Operating Systems reserve random, unused ports for some applications. It may happen that a certain WinCC OA default port is occupied by Windows before starting the WinCC OA manager so that it is able to occupy this port first. This may have the effect that a WinCC OA project cannot be started - this occupation is not shown in the Windows Task Manager. How to reserve ephemeral ports in Windows in a way that they will not be occupied randomly, can be read in this Microsoft instruction http://support.microsoft.com/kb/812873/en-us .