Omron CJ Series User Manual

5-37
5 Operation
CJ-series PROFIBUS Master Unit Operation Manual for NJ-series CPU Unit (W509)
5-5 I/O Communication Characteristics
5
5-5-5 I/O Response Time
PROFIBUS DP I/O data exchange cycle < CPU cyclic refresh results in the following I/O transfer
characteristics.
• All output data sent by the CPU is transmitted over the PROFIBUS network.
• Not all Input data is transferred to the CPU (referring to the figure above: Input data marked
with I+1, I+4, I+6 and I+8 are lost).
Note To prevent input data not being transferred to the CPU, the CPU cyclic refresh time must be
at least two times the PROFIBUS DP cycle time.
The maximum I/O response time is defined as the time from the moment an input on a slave device
with the lowest PROFIBUS address is switched TRUE (FALSE) until the moment the output on a
slave device with the highest PROFIBUS address is switched TRUE (FALSE).
 PROFIBUS DP Cycle > CPU Cyclic Refresh
The figure below shows the timing in case the PROFIBUS DP cycle > CPU cyclic refresh.
5-5-5 I/O Response Time
CPU Cycle
PROFIBUS Cycle Cycle n
CIO Refresh
Output data refresh
O O+1 O+2 O+4
Input data refresh
I
O+3
Cycle
n+1
Cycle
n+2
Cycle
n+3
Cycle
n+4
Cycle
n+5
Cycle
n+6
Cycle
n+7
Cycle
n+8
I+1 I+2 I+3 I+4 I+5 I+6 I+7 I+8
Unit requests
cyclic refresh
Unit requests
cyclic refresh
Unit requests
cyclic refresh
Unit requests
cyclic refresh
Unit requests
cyclic refresh
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Omron CJ Series Specifications

General

Brand	Omron
Model	CJ Series
Category	Controller
Language	English