Siemens COMBIMASTER 411 Operating Instructions Manual page 18

COMMUNICATION
drive in the automation network. Process data is always transferred. It is processed
as top priority in the shortest time slice in the drive.
Process data is used to control the drive in the automation network, On/Off
commands, setpoint inputs, etc.
The parameter area enables the user to access all parameters stored in the
inverter via the bus system. For example, to read out detailed diagnostic
information, faults messages, etc.
Telegrams for cyclic data transmission thus have the following basic structure:
Protocol frame
(header)
1
PKW: Parameter identifier value
Five types of Parameter Process data Object (PPO) are defined (see Figure 3.2)
according to PROFIDrive Profile, version 2.0 and these contain:
Ø Useful data without parameter area, with two or six words of process data or
Ø Useful data with parameter area, with two, six or ten words of process data.
18
Useful data
1
Parameter (PKW) Process data (PZD)
PPO
PROFIBUS Communication Module
Issue 03/02
Protocol frame
(trailer)
Operating instructions
6SE6400-5AV00-0BP0