4 - 6 4 - 6
MELSEC-Q
4 WHEN THE QCPU ACCESSES THE OTHER STATION PLC USING THE
DATA LINK INSTRUCTION
(Example) READ instruction execution timing
1) Communication timing when the READ instruction completed
successfully (when resend is not performed)
QCPU
E71 (Local station)
READ
(Execution
completion)
Read request
Read data
E71
(Other station)
Q/QnACPU
Command (UDP)
Receive response
(UDP) ( 4)
Response
Receive response
(UDP) ( 4)
Arrival
monitoring
time ( 1)
2) Communication timing when the READ instruction completed
successfully (when resend is performed)
QCPU
E71 (Local station)
READ
Read request
Read data
E71
(Other station)
Q/QnACPU
Command (UDP)
Receive response
(UDP) ( 4)
( 3)
Command (UDP)
Receive response
(UDP) ( 4)
Response
Receive response
(UDP) ( 4)
(Execution
completion)
(Resend)
Repeat for
the number
of resend.
( 2)
Arrival
monitoring
time ( 1)
1 The user designates the arrival monitoring time with the READ
instruction control data ((S1)+8).
2 The user designates the number of resend with the READ
instruction control data ((S1)+7).
3 Indicates the response not returned within the arrival
monitoring time.
The Ethernet module performs a resend of the command for
the number of resend when this response is not received.
4 The "receive response (UDP)" in the diagram is for the
interlock between the Ethernet module, and this is the
response to the partner station Ethernet module from the
Ethernet module OS.
Содержание QJ71E71-100 Series
Страница 2: ......
Страница 214: ...6 65 6 65 MELSEC Q 6 DEDICATED INSTRUCTIONS MEMO ...
Страница 219: ......