DS200TCEAG1ACB Gas turbine electrical module

 Now, no answer is received, and the bus master transfers to point 3. Again, no answer is received, and the bus master transfers to point 4. Here, another collision is detected, and the communication interface transfers to point 5, where only a single answer is received.Eventually, only a single answer is received (a two byte slave frame). These two bytes contain a function code and an address/control field, exactly like a master frame. The slave frame constitutes a master frame which the bus master must send when possible in order to serve the communication interface that answered. For message transfer, the two byte slave frames (to be used as master frames) will contain function code 12 and the address of the communication interface in question in the address/ control field. When the bus master sends this frame as a master frame, the other communication interface is able to transmit its packet, as described in Message Transfer on page 285

Completing the Round

 If collisions were detected during the above event location procedure, the bus master starts again from the top (using function code 9). However, this time no new round is initiated, meaning that only the communication interfaces which have not already been served may answer! This guarantees that all communication interfaces will eventually be served, and that no starvation problems occur. When all communication interfaces have been served, the bus master starts with function code 9 again, indicating that a new round is to begin, thus allowing all communication interfaces to answer.

CDP Configuration

 When a sending CDP is configured or updated, the associated communication interface engages in a configuration protocol with the other communication interfaces. First, it requests to become bus master, as the configuration protocols require that only the bus master may distribute configuration data on the Advant Fieldbus 100. Then it distributes the configuration changes to the other communication interfaces, one by one. These, in turn, regenerate their scan tables in order to support the new configuration. In case a communication interface, not master defined, has CDPs to be configured or updated, this is performed through a master defined communication interface.