Mitsubishi MELSEC-Q Series User Manual page 99

4 FUNCTIONS
PLC CPU
(Sequence scan)
Master station buffer memory
(Remote input RX)
Link scan
Response time of the first station
Response time of the corresponding station
Responses from remote
I/O stations
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(4) Data flows in synchronous and asynchronous modes
The data flows in both the synchronous and asynchronous modes are explained
using examples of communications between the master station and remote I/O
stations.
(a) Data flow in the asynchronous mode
Response time of the final station
Input 1)
I: Delay time due to response delay of remote I/O station
II: Delay time of transmission from the remote I/O station to the master
station
III: Delay time from reception by the master station to storage in the buffer
memory
IV: Delay time until the master station's information is refreshed in the PLC
CPU
Input 2) Input 3)
I II III
Transmission delay time
MELSEC-Q
IV
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