DeviceNet is a standard, open bus system acc. to EN50325 which is based on the CAN specification (Controller Area Network). As a multi-master system DeviceNet provides the following I/O communication modes:
Polled‐I/O: The master/scanner transmits the output data cyclically to the related nodes and receives the input data as a response telegram.
Bit‐Strobed‐I/O: The input data is requested from all nodes by the scanner/master with a broadcast telegram.
Change‐of‐State: The telegrams are only transmitted from the slave to the master/scanner in the event of state change. Only the actual change is transmitted and not the complete process image.
Cyclic‐I/O: The slave transmits the data to the master/scanner after a determined cycle time.