4 - 12 4 - 12
MELSEC-Q
4 WHEN THE QCPU ACCESSES THE OTHER STATION PLC USING THE
DATA LINK INSTRUCTION
(2) Instruction execution timing (for receive processing by the main
program)
(a) When normal completion
Channel 3
Channel 1
Data
sending
Storage
complete
0
END
Sequence scan
0
END
0
END
0
END
0
END
Send command
SEND
(With arrival confirmation)
1 scan
0
END
Sequence scan
0
END
0
END
0
END
RECV
0
END
0
1 scan
?
Receive data
OFF
OFF
Send completion device
(Device designated with (D))
Sending side
Q/QnACPU
Send completion
device ((D)+1 device)
Ethernet
module
Ethernet
module
Receiving side
Q/QnACPU
Receive completion device
((D2)+1 device)
Receive completion device
(Device designated with (D2))
Receive data storage device
(Device designated with (D1))
RECV instruction exection
request flag ( 1)
1 The RECV instruction execution request flag for Channel 3 used at the receiving
side Q/QnACPU is as shown below.
For Ethernet module : Bit 2 of the RECV instruction execution request area
(address: 205) in the buffer memory
For the N/W module
: SBA2 of the link special relay
