Explanations relating to some Profibus data

Data traffic between the DPM1 and its assigned DP slave devices is automatically handled by the DPM1 in a defined, recurring sequence. When configuring the bus system, the user defines the assignment of a DP slave device to the DPM1. The user defines which DP slave devices are to be included in the cyclic user data traffic and which DP slave devices are to be excluded from the cyclic user data traffic. Data traffic between the DPM1 and the DP slave devices is divided into the phases of parameterization, configuration and data transfer. Before a DP slave device is included in the data transfer phase, the DPM1 checks (in the parameterization and configuration phases) whether the current target configuration corresponds to the actual device configuration. The device type, format information and length information as well as the number of inputs and outputs must match. This provides the user with reliable protection against parameterization errors.

Station-related messages on the general readiness for operation of a device are transmitted. Module-related messages indicate a diagnosis within a specific I/O subrange of a device. The error causes are specified in relation to a single input bit or output bit.