PROFINET uses the IEEE 802.3 (Ethernet) based PROFINET RT protocol for cyclic real-time I/O communication and RPC (Remote Procedure Call) via UDP/IP for acyclic services. Any kind or number of network topology is possible. The network can be used parallel to other protocols, such as TCP/IP.
DCP (Discovery and basic Configuration Protocol) is a subprotocol of PROFINET RT which is used for the device scan and to set the station names or the IP configuration. Communication via PROFINET RT and DCP does not require an IP address, but uses the MAC of the Ethernet interface directly for address.