Allen-Bradley POINT I/O PROFIBUS 1734-APB, User Manual, Page: 40 / 88

Publication 1734-UM005B-EN-P - June 2001
4-2 Communication and I/O Table Mapping
How Data Communication
Takes Place
Before any data transfer can take place, the adapter has to verify and
accept the PROFIBUS services Set_Parameter and
Check_Configuration that are sent from the master at startup. If the
adapter accepts these services, data transmission is executed
automatically in a cyclic manner with the Data_Exchange service. In
addition to these 3 services, the adapter may notify the master of its
current status by means of the Slave_Diagnostic service.
The master can read the actual configuration with the
Get_Configuration service and send control commands to the adapter
by means of the Global_Command service.