How data communication takes place – Rockwell Automation 1734-APB Point I/O Profibus Adapter Module User Manual

Page 40

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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.

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