There are three device types according to PROFIBUS DP:
PROFIBUS DP Master Class 1. This class controls the communication process for exchanging process values, with individual slaves using the defined cyclic commands during the configured timeslots. Devices include controllers and PCs.  PROFIBUS DP Master Class 2. This class accesses the fieldbus by using acyclic services, enabling the configuration and parameterization of intelligent field devices. Devices include engineering and operator panels. PROFIBUS DP Slave. These peripheral devices read input information and send output information to the periphery. Devices can process a maximum of 246 bytes of input data and 244 bytes of output data.