Direct Access To Link Devices - Mitsubishi Electric MELSEC Q Series Reference Manual

4.1.4

Direct access to link devices

Data can be directly read from or written to link devices (LB/LW/LX/LY/SB/SW) of the CC-Link IE Controller Network
module using the sequence program.
Specify a link device in the link direct device (J\) for direct access.
Send
request
J1\B100
Send
request
MOV K20 J1\W100
= J1\W200 K300
Output
instruction
J1\Y1000
J1\X1100
● To assure cyclic data integrity of data exceeding 32 bits, configure an interlock program. (
● When a shorter link refresh time is desired
Remove any infrequently used link devices from the link refresh range, and directly read or write them using link direct
devices.
This reduces the points of the link refresh to the CPU module, resulting in a shorter link refresh time. (
Section 6.5)
● When a shorter transmission delay time is desired
Since the link direct device reads or writes data directly to the link devices of the CC-Link IE Controller Network module at
the time of the instruction execution, the transmission delay time can be reduced. (
Link refresh is performed in "END processing" of the sequence scan of the CPU module.
70
Control station
No.1
CC-Link IE Controller
CPU module Network module
J1\B0
X Y LX
Actual I/O Actual I/O
Network No.1
CC-Link IE Controller
Network module
LB0 LB0
Station Station
No.1
LB100 LB100
Station Station
No.2
LW100 LW100
Station Station
No.1
LW200 LW200
Station Station
No.2
LY LX
1000 1000
11FF 11FF
Normal station
No.2
No.1
No.2
No.1
No.2
LY
Cyclic transmission
Link refresh
Page 76, Section 4.1.5)
Page 74, Section 4.1.4 (4))
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