Omron CJ Series - Page 190

5 Operation
5-38
CJ-series PROFIBUS Master Unit Operation Manual for NJ-series CPU Unit (W509)
T
IN
Slave device Input TRUE (FALSE) delay.
T
PB,Cyc
PROFIBUS I/O data exchange cycle time (See Appendix A Bus Parameters)
T
M,Proc
I/O Processing time in the Master Unit. Minimum value is 430 s but may increase
with increasing I/O data size.
T
M,Rrf
Master request cyclic refresh until actual start of cyclic refresh.
T
CPU,Cyc
CPU cycle time.
T
CPU,Rf
CPU cyclic refresh time.
T
OUT
Slave device Output TRUE (FALSE) delay.
The total I/O response time is the sum of all components:
T
IO
= T
IN
+ 4*T
PB,Cyc
+ 2*T
M,Proc
+ T
M,Rrf
+ 2*T
CPU,Cyc
+ T
CPU,Rf
+ T
OUT
Note The calculation assumes the presence of only one Master Unit on the PROFIBUS network.
 PROFIBUS DP Cycle < CPU Cyclic Refresh
The figure below shows the timing in case the PROFIBUS DP cycle < CPU cyclic refresh.
PROFIBUS Cycle
Slave I/O data refresh
Slave I/O data refresh
TRUE
CPU Cycle
T
PB,Cyc
T
CPU,Cyc
TRUE
T
PB,Cyc
T
CPU,Cyc
T
M,Proc
T
IN
T
OUT
T
M,Proc
+ T
M, Rrf
T
CPU,Rf
T
PB,Cyc
T
PB,Cyc
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PROFIBUS Cycle
Slave I/O data refresh
Slave I/O data refresh
T
PB,Cyc
T
CPU,Cyc
TRUETRUE
T
PB,Cyc
T
M,Proc
+ T
M,Rrf
T
CPU,Cyc
T
M,Proc
T
IN
T
OUT
CPU Cycle
T
CPU,Rf
T
PB,Cyc
T
PB,Cyc
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Execution
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