MVB process data is periodically broadcast data. It is divided into a total of 4096 logical ports (port numbers range from 0 to 4095). The data length of each PD port can be set to 2, 4, 8, 16, or 32 bytes.
If an MVB device on the bus needs to send PD data, it configures the corresponding PD port as a source port. If it needs to receive data from a certain PD port, it configures that PD port as a sink port.
The MVB master station (bus manager) periodically sends master frames with Fcode from 0 to 4 (corresponding to data lengths of 2 to 32 bytes) according to the configuration. These master frames contain the PD port numbers. If an MVB slave device on the bus finds that the PD port number in the master frame is the source port of its own device, it sends a slave frame containing process data to the bus. Other devices only receive the slave frame data configured as sink ports.
The characteristics of MVB process data are summarized as follows:
• It is periodically broadcast data.
• The sending cycle is controlled by the master station.
• The sending slave station configures the sending port as a source port.
• The receiving slave station configures the receiving port as a sink port.
