Lenze EMF2133IB - Process Data Transfer

Process data transfer 7
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EDSMF2133IB EN 5.0
7 Process data transfer
request
response
2133PFB008
Fig. 7−1 PROFIBUS process data transfer
PROFIBUS transmits parameter data and process data between the host (master) and the
controllers connected to the bus (slaves). Depending on their time−critical nature, the data
are transmitted via different communication channels.
ƒ Process data are transmitted via the process data channel.
ƒ Process data serve to control the drive controller.
ƒ The transmission of process data is time−critical.
ƒ Process data are cyclically transferred between the host and the controllers
(continuous exchange of current input and output data).
ƒ The host can directly access the process data. In the PLC, for instance, the data are
directly assigned to the I/O area.
ƒ With the function module a maximum of 10 process data words (16 bits/word) can
be exchanged in each direction.
ƒ Process data are not stored in the controller.
ƒ Process data are, for instance, setpoints, actual values, control words and status
words.
) Note!
Observe the direction of the information flow!
ƒ Process input data (Rx data):
– Process data from controller (slave) to host (master)
ƒ Process output data (Tx data):
– Process data from host (master) to controller (slave)