Lenze E84Dxxxx - Manual (Page 28)

EDS84DPBUS EN 2.0 - 09/2010
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Communication manual 8400 protec PROFIBUS
Data transfer
6 Data transfer
PROFIBUS master and controller communicate through the exchange of data telegrams via
PROFIBUS. The user data area of the data telegram contains parameter data or process
data. In the controller, different communication channels are assigned to the parameter
data and process data.
Communication channels
 The process data channel serves to transfer process data.
– The process data serve to control the controller.
– The host can directly access the process data. In the PLC, for instance, the data are
directly saved to the I/O area.
– Process data are not saved in the controller.
– Process data are transferred cyclically between the host system and the controllers
(permanent exchange of current input / output data).
– Process data are, for instance, setpoints, actual values, control words and status
words.
– The Inverter Drives 8400 can exchange a maximum of 16 process data word (16 bits/
word) per direction.
 The parameter data channel serves to transfer parameter data.
– The parameter data channel provides access to all Lenze codes.
– In general, the parameter data transfer is not time-critical.
– Parameter data are, for instance, operating parameters, diagnostic information, and
motor data.
– Changes to parameters must be saved via code C00002 of the Inverter Drives 8400
protec.
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Note!
Observe the direction of the information flow!
• Process input data (Rx data):
– Process data from the controller (slave) to the master
• Process output data (Tx data):
– Process data from the master to the controller (slave)