The PROFIBUS DP/DP coupler interconnects two PROFIBUS DP networks. Byte data (0 … 244 byte) is transferred from the DP master of the first network to the DP master of another network and vice versa.

The principle corresponds to the hardware wiring of inputs and outputs used today. The coupler has two independent DP interfaces with which the two DP networks are connected.

The DP/DP coupler is a slave on each DP network. The interchange of data between both DP networks takes place by internal copying in the coupler.