Mitsubishi MELSEC-A Series Reference Manual page 170

7. DATA LINK SETTINGS
(1)
(2)
Assignment of link relay (B)
Data link cannot be executed by using a link relay in a remote I/O system.
(Setting at link parameter is unnecessary.)
Assignment of link register (W)
(a) Assignment for remote I/O stations (M
1) Assign 16 points for the RTOP instruction and 16 points for the RFRP
instruction in the user program of the master station as remote I/O station
No.1.
No.1 requires 17 points (16 points (for RTOP) + 1 point (for OS)) for the M
R area because one special function module is installed.
2) Assign 32 points for the RTOP instruction and 32 points for the RFRP
instruction in the user program of the master station as remote I/O station
No.2.
No.2 requires 34 points (32 points (for RTOP) + 2 points (for OS)) for the M
R area because two special function modules are installed.
Fig 7.13 Link register (W) assignment example
(b) In Fig 7.13, the empty area marked with *1 in the M
a data register (D) by the master station.
R area, M
7 - 32
R area)
R area cannot be used as