Lenze I/O system 1000 System Manual - Manual (Page 390)

PROFIBUS communication
Communication
Cyclic data transfer
9
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390 EDSIO1000 EN 7.0
9.3.2 Cyclic data transfer
The data communication with PROFIBUS−DP−V0 includes cyclic diagnostics as well as cyclic
process data and parameter data transfer.
Master
(DPM 1)
Slave
buffer receive
Communications
processor
PA
buffer send PE
0 1
 ‚
epm−t228
Fig. 9−3 DP cycle and cycle of backplane bus
0
Backplane bus with transmit and receive buffer
1 Input / output modules
PO: process image of outputs
PI: process image of inputs
 PROFIBUS cycle
‚ Backplane bus cycle
Backplane bus cycle
During a backplane bus cycle
ƒ the input data (PI) on the inputs is collected and transmitted to the transmit buffer
(buffer send),
ƒ the output data (PO) of the receive buffer (buffer receive) is written to the outputs.
PROFIBUS cycle
During a PROFIBUS cycle, the master successively addresses all its assigned slaves with a
DataExchange. During a DataExchange, the memory areas assigned to the PROFIBUS are
transmitted.
ƒ The data of the PROFIBUS input area is transmitted to the receive buffer (buffer
receive).
ƒ The data of the transmit buffer (buffer send) is transmitted to the PROFIBUS output
area.