PROFINET Manual

A TAP (Test Access Point) decouples the data stream to be analyzed without the limitations of port mirroring with regard to data rate and changes to packet content. The TAP is inserted directly into a network connection as shown in Figure 67.

Figure 67:  Reading out data traffic using TAP

•Using TAP, data streams can be read out without the limitations of port mirroring with regard to data rate and changes to packet contents.

•Inserting and removing the TAP requires disconnecting the network connection.

•Only the data stream "flowing" through the TAP can be evaluated.

•Passive TAPs should be preferred, since a failure of a passive TAP does not lead to a failure of the communication path.

•If the TAP remains in the network, diagnostics can be performed later without having to disconnect the network connection again.